mm %■/ Vi<* t Jt >=« ^i Ill ^. ,7. Ca,^ Anecdotes 4 Cabinets useful, but not indis- pensable 5 Study of Insects does not narrow the mind ...... 6 Injuries and benefits caused by Insects 7 Use of names in Natural History. 11 Study of Insects fascinating to youth 11 Anecdote of a little girl . . .11 Beauty of Insects 12 Varieties in the economy of Insects 14 States of Insects 16 Insects produced from eggs . .16 Larva, Caterpillar, Grub, Maggot 16 Pupa, Chrysalis, Aurelia, Nymph 18 /ma^o, perfect Insect . . . .19 CHAPTER II. Structures for protecting Eggs . . 20 Eggs of Insects can bear great degrees of heat and cold . , 20 Bees compared to our mechanics . 21 Mason-Wasps 22 Curious proceedings of one at Lee 22 Her caution outwitted by a Fly . 24 Structures of another Mason- Wasp 24 Her storing of live Caterpillars . 27 Mason-Bees. ...... 27 Nest of one on the wall of Green- wich Park 28 Clay-mine of Mason-Bees at Lee . 29 Estimate of their labours ... 31 Wall-Mason Bees of France . .31 Proceedings of the two-horned Mason-Bee at Lee . . . .33 Structures of Mason-Bees. . . 34 Their restless disposition ... 35 Mining-Bees 36 Their different proceedings in Britain and in France . . .36 CHAPTER III. Carpenter-Bees 38 Methods of working .... 38 History of one at Lee . . . .39 Violet Carpenter-Bee of France . 40 Compared with our joiners . . 42 Elder and Bramble Carpenter Bees 43 Carpenter-Wasps 44 Curious cocoon of. .... 45 Upholsterer-Bees ..... 45 Poppy-flower Bee of Largs and ofBercy 45 Taste of the little architects in ornament 46 Cotton-gathering Bee .... 48 Rose-leaf-cutter Bee .... 50 Her method of working ... 50 Anecdote of St. Fi-ancis Xavier . 53 CHAPTER IV. Carder-Bees 54 Method of preparing and con- veying their materials ... 54 Structure of their nests ... 56 IV CONTENTS. Page Lapidary-Bees 59 Pertinacity in defending their nest 59 Hamble-Bee^ 59 Structures of their nests ... 59 Social-Wasps 59 Nest founded by a single female . 59 Compared with the Burrowing- Owl 61 Materials rasped off from wood . 62 Different opinions of Naturalists . 63 Paper made by Wasps ... 63 Structure of the nest .... 63 Extraordinary number of cells . 65 Hornet's nest 67 Tree- Wasps' nests in Ayrshire . 68 Rose-shaped Wasps'-nest . . .69 Vertical Wasps'-nest .... 70 Wasp-paper compared with ours . 72 Card-making Wasp of Cayenne . 74 CHAPTER V. Architecture of the Hive-Bee. . 78 Discoveries from Aristomachus to Maraldi and Huber ... 78 Nurse-Bees and Wax-workers . 80 Preparation of wax .... 81 Erroneous account by the Abb^ la Pluche 82 Conjectures of Reaumur. . . 83 Discovery of John Hunter . , 83 Experiments of M. Huber . . 84 Singular facts by Mr. Wiston . 87 Dissections by Huber, Madlle. Jurine, and M. Latreille . . 89 Propolis 91 Opinions of Old Naturalists . . 92 Discovery by Huber. ... 92 Various uses of propolis. . . 93 Mr. T. A, Knight's observations 95 Basket for carrying on the thighs of Bees 96 Process of loading . . . .96 Building of the cells .... 97 Division of labour .... 97 Festooned curtain of Wax-workers 98 Commencement of the combs . 100 Huber's history of his experimentslOO Secretion of wax 101 Foundation of the first cell . .101 Workers extract their own wax . 101 View of the proceedings obstructed 104 CHAPTER VI. Pac Form of the cells 105 Mathematical problem solved by Bees 105 Calculated by ]\Iaraldi and Koenig 106 Reasons for the form of the cells. 106 Referred to the form of the Bee. 107 Experiments of Huber . . . 107 Cells commenced in the foundation- wall 109 Deepening of the cells . . .111 Polishing by Nurse-Bees . .112 Distance of the combs from each other 113 Dr. Barclay's discovery . . .114 Irregularities in their workmanship 114 Anecdote from Dr. Bevan . .114 Similar anecdote from Huber , 115 Symmetry in the architecture of Bees explained . . , .116 Curved combs 116 Experiments of Huber . . .117 Size of male cells .... 118 Cells enlarged when honey is plentiful 119 The finishing of the cells . , .120 Varnished with propolis . .120 Strengthened with pissoceros . 121 Discovery by Huber . . . 121 Cells strengthened by the Bee- grubs 123 Difficulties explained . . . 123 Mistake of an American writer . 123 Curious experiments of Huber . 124 Wild Honey-Bees 124 Wild-Bees of America, Ireland, Palestine 124 Honey-guide of Africa . . .126 Bee-hunting in America. , . 127 CHAPTER VII. Carpentry of Treehoppers (Cicadoe) 129 Mistaken for Grasshoppers , .129 Singular cutting instrument of the Treehopper 130 Double files of 131 Their nests 132 Saw-Flies 133 Their ovipositor 133 Structure of 134 CONTENTS. Page Comb-toothed rasp, and saw . 136 Grooves cut by it in the rose-tree 136 CHAPTER VIII. Leaf-rolling Caterpillars . . .140 Lilac-leaf Roller .... 141 Oak-leaf Roller 143 Rose-leaf Roller 143 Nettle-leaf Roller .... 144 Method of proceeding , . . 145 Probable mistake concerning. . 146 Sorrel-leaf Roller .... 147 Admirable and Painted Lady Butterflies 148 Mallow-Butterfly of France . . 149 Willow-leaf Bundler . . .149 Nest of Ziczac Caterpillar . . 150 Nest of Glanville Fritillary . . 151 Experiment on gregarious Cater- pillars by J. R 152 Design in rolling leaves . . .153 CHAPTER IX. Habitations formed of detached leaves 154 The Pond weed Tent-maker . .154 Chickweed Caterpillar's nest . 156 Cypress-spurge Caterpillar's nest 156 Durability of these structures . 157 Moss-cellof a Wall-Caterpillar . 158 Caterpillar of Greenwich Park wail CHAPTER X. . ioy Caddis-Worms . 161 Leaf and reed nests of . . 161 Shell nests of . . . . 162 Stone and sand nests of . . 162 Nest balanced with straws . 163 Carpenter-Caterpillars . 164 Caterpillar of Goat-Moth . 164 Its winter nest . . . . 165 Singular nest of . . . 165 Nest of the .Egeria in a Pop lar. 167 Paper-nest of the Puss-]\Ioth . . 168 How it escapes from its cell . 169 Purple Capricorn-Beetle . . . 170 Page Bark-building Caterpillar of the Oak 172 CHAPTER XI. Earth-Mason Caterpillars. . .174 Outside walls of their nest . .174 Caterpillar of Ghost-Moth . . 175 Experiments of Reaumur . .177 Nests of Ephemera Grubs . . 179 Similar nests in a willow stump 179 Nests of the Cincindela-Beetle . 179 The Ant- Lion 182 Structure of the Grub . . .182 Formation of its traps . . . 183 Reflections upon the economy of Nature 187 CHAPTER XII. Clothes-Moth Caterpillars . .190 Varieties in the species . . .190 Methods of destroying . . . 191 Mode of building . . . .191 Experiments upon . . . .192 Migrations of 194 Tent-Making Caterpillars. . . 195 Mode of constructing these . . 196 Experiments upon . . . .196 Tent upon a Nettle-leaf . . .198 Stone-Mason Caterpillars . . . 199 Their singular proceedings . . 199 Colony of, at Blackheath . . 200 Foundation of their tents . . 201 An attempted robbery . . . 202 Muff-shaped tents . . . .202 Their utility 204 • Leaf-mining Caterpillars . . . 204 On the leaf of the IMonthly Rose- tree 204 On the leaf of the Bramble . . 206 On the leaf of the Primrose . . 207 On the leaf of the Alder . . .208 Vine-leaf Miner 208 Social Leaf-Miners .... 209 Bark-mining Caterpillars. . , 209 CHAPTER XIH. Structures of Crickets . . .211 The House-Cricket . . . .211 The Mole-Cricket . . . .211 The Field-Cricket . . . .214 VI CONTENTS. Mode of depositing eggs Beetles .... Tiie Burying-Beetle . The Dung-Beetle Its cleanliness The Rose-Chafer. The Tumble-dung Beetle The Necklace-Beetle. Page 215 , 216 , 216 218 , 219 , 220 . 220 . 221 CHAPTER XIV. Architecture of Ants. . . .222 Their genuine history begun by Gould. ..."... 222 Mason-Ants 223 Structures of Turf-Ants. . .223 Winter nest of Yellow Ants. • 224 Sort of earth employed in building 225 Proceedings of the Brown Ants , 226 Raft formed by American Ants . 227 Blind Ants ." 228 Night proceedings of Ants . . 229 Proceedings during rain . . . 229 Experiments 229 History of a labouring Ant, by M. Huber 283 Glazed Artificial Formicaries . 236 Section of a ]Mason- Ant's nest . 236 Experiments by J. R. . . . 236 CHAPTER XV. Structures of the Wood-Ants, or Pismires 238 Materials employed .... 238 Coping of their nest .... 239 Interior structure .... 240 Glazed Formicary for experiments 241 Their proceedings at nightfall . 241 Carpenter-Ants 243 Emmets, or Jet-Ants . , . 244 Their galleries in trees . , •. 244 Extremely populous colony at Brockley 246 Dusky Ants 247 Foreign Ants 247 Sugar- Ants of the West Indies . 250 CHAPTER XVI. Structures of White Ants, or Ter- mites 251 Their extraordinary comparative height 251 Their mining operations . The Warrior {Termes Bellicosus). Used as delicate food Commencement of their nests Royal chamber . . . . , Nurseries Galleries and covered ways . Turret-building White Ants . Singular form of their nests. White Ants of trees and timber . Death-Watch .... Page 252 254 255 255 257 259 260 263 263 264 266 CHAPTER XVII, Spinning-Caterpillars . . . 267 Manifold advantages of spinning. 267 Structure of their legs and feet . 268 Side spiracles for breathing . . 268 Internal structure .... 269 Structure of the silk-tube . . 269 Mode of Spinning described by La Pluche 270 Silk- Worms . . . . . .273 Their transformations . . . 273 How they make their exit from the cocoons 276 Parts used in our manufactures . 277 History of the introduction of silk 277 Varieties and species of silk- worms 279 Emperor-Moth 279 Ingenious contrivance of the co- coon 280 Spinning-Caterpillars continued . 281 Elastic cocoon of Tortrix chlorana 281 Slender covering of the Gipsy- Moth 282 Cocoon of the Cream-spot Tiger- Moth 283 Experiment with the Dock- Weevil 283 Nest of Puss-!Moth, with cocoons of Ichneumons .... 283 Cocoon of the Horned IVIason-Bee 284 Experiment with Eriogaster lanestris 285 Social Spinning-Caterpillars , . 286 Winter nest of the Brown -tail Moth 287 Winter nests of the Golden-tail Moth 286 CONTENTS. Vll Pendulous leaf-nests, from Bonnet 289 NestofProcessionary Caterpillars 290 CHAPTER XVIII. Structures of Spiders .... 292 Spiders not properly insects, and why 292 Apparatus for spinning . . . 292 Extraordinary number of spiune- rules 293 Attachment of the end of a thread 295 Shooting of the Lines of Spiders . 296 1. Opinions of Redi, Swammer- dam, and Kirby .... 296 2. Lister, Kirby, and White 297 3. La Pluche and Bingley 299 4. '- D'Isjonval, Mur- ray, and Bowman .... 300 5, Experiments of Mr, Blackvvall 302 His account of the ascent of gossamer 303 6. Experiments by J, R. . . 304 Thread supposed to go off double 305 Subsequent experiments . . . 306 Nests, Webs, and Nets of Spiders. 308 Elastic satin nest of a Spider . 309 Evelyn's account of Hunting Spiders 309 Labyrinthic Spider's nest . .311 Erroneous account of the House Spider 311 Geometric Spiders .... 312 Mason-Spiders 313 Ingenious door with a hinge. . 314 Nest from the West Indies, with spring hinge 314 Raft-Buildmg Spider . . . .316 Diving Water-Spider . . . .318 Observations of M. Clerck . .318 Cleanliness of Spiders, , . .319 Structure of their claws . . . 320 Fanciful account of them patting their webs 321 Proceedings of a Spider in a steamboat 321 CHAPTER XIX. Structures of Gall- Flies . . 323 Page Berry Gall of the oak-leaf, &c. . 323 Ingenious mechanism of the ovi- positor 324 Opinions of Naturalists as to the cause of galls . . .' . .326 Bedeguar of the rose. . . . 328 Artichoke gall of the oak . . 329 Leaf-gall of Dyer's broom . . 331 Rose-willow ...•*. 331 Rose-hawthorn 332 Woolly gall of the oak ■ . . .332 Experiments with the Flies . . 333 Oak-apples 335 Root-galls of the oak . . . 336 Woody gall of the willow . . 336 Oak currant-galls . . . . 337 Weevil-Galls 338 Weevil-gall of the hawthorn . 338 Anbury on the roots of cabbages, &c 339 Semi-Galls of Aphides . . ,340 Mountain-ash leaf-galls . . . 340 Poplar semi-galls oi' the cottony aphis 341 Leaf-rolling Aphides .... 343 Leaf of the currant-bush thus altered 343 Shoot of the lime-tree thus con- voluted 344 Pseudo-Galls 345 Pseudo-gall of the bramble . . 346 • hawthorn. , 346 Scotch fir. . 347 CHAPTER XX. Animal-Galls .349 Enthusiasm of M. Reaumur for study 349 Ovipositor of Breeze-flies . . 350 Opinion of Mr. Bracey Clark on its use 351 Effects produced by the fly upon cattle 352 Observations of Linnaeus on the Reindeer Breeze-fly . . . 353 Opinions of Kirby and Spence . 354 Observations of Mr. B. Clark . 355 Hatching of the egg .... 357 Bumps, or wurbles, thence pro- duced 357 Communication of the grub with the air. ...... 359 VUl CONTENTS. Page F'inal cause of these bnmps . . 360 The Zimb (Breeze-fly ?) of Africa 361 Human Breeze fly .... 361 Grub Parasite in the Garden-Snail 361 Caterpillar'Parasite in the same 362 MISCELLANIES. I. — On the ravages of Insects : — • Voracity of Caterpillars, Grubs, and ]\Iaggots 363 Caterpillars 369 Grubs 387 Maggots 404 II. — On the Collection and Preser- vation of Insects for the pur- poses of Study : — Breeding-cage 425 Larvse-box . Pocket collecting-box Water-net Butterfly-net. Clap-net . . Ring-net. Net forceps . Digger Chip collecting- box Method of setting Insect Cabinet. Page 429 430 430 430 431 432 432 434 , 435 , 437 . 438 III. — Systematic Arrangements of Insects : — The Wing System .... 440 The Locality System . . . 442 The Transformation System. . 444 The Cibarian, Maxillary, or Mouth System 446 The Ovary, or Egg System . . 447 The Eclectic, or JModern System 448 The Quinary System .... 451 ( ix ) ILLUSTRATIONS. 1 Eggs of insects, magnified 2 Larvae, grubs, caterpillars, or maggots 3 Pupae, or chrysalides . 4 Insects in the imago or perfect state 5 Mason-wasp .... 6 Jaws of mason-wasp, magnified 7 Cuckoo-fly ... . . 8 Mason-wasp's nest and cocoons 9 Mason-wasp .... 10 Nests, &c., of mason-wasps . 11 Mason -bee .... 12 Exterior wall of mason-bee's nest . 13 Cells of mason-bee's nest 14 Varieties in cells of mason-bee's nest, thre 15 Mason-bee and nest 16 Cell of mining-bee 17 Cells of carpenter-bees, two figures . 18 Carpenter-bee and cells 1 9 Teeth of carpenter-bee, magnified . 20 Nests of carpenter-wasps, two figures 21 Carpenter-wasp .... 22 Cocoon of a carpenter-wasp . 23 Rose-leaf cutter-bees, and nest lined with 24 Carder-bees heckling moss for their nests 25 Exterior of the carder-bee's nest 26 Breeding cells of the carder-bee 27 Interior of carder-bee's nest, two figures 28 Section of social-wasp's nest . 29 Suspension rod of social-wasp's nest 30 Portion of external crust of social-wasp's 31 Hornet's nest in its first stage 32 Singular wasp's nest . 33 Wasp's cells attached to a branch . 34 Nest of the pasteboard-maker wasp. 35 Part of a honeycomb and bees at work 36 Worker-bee, magnified 37 Abdomen of wax-working bee 38 Structure of the legs of the bee for carryi 39 Curtain of wax-workers secreting wax 40 Wax-worker laying the foundation of the 41 Curtain of wax-workers . . 42 Arrano-ement of cells of hive-bees fio-ures nest g propoli first cell ose-leaves &c. ILLUSTRATIONS. 43 Foundation-wall enlarged and the cells commenced 44 Ovipositors, with files, of the tree-hopper, magnified 45 Excavations for eggs of tree-hopper, with lid raised 46 Ovipositor of saw-fly protruded from its sheath 47 Ovipositor saw of saw-ffy, magnified 48 Portion of saw-fly's comb-toothed rasp, and saw 49 Nest of eggs of saw-fly . . . , 50 Lilac-tree moth ..... 51 Nest of a lilac-leaf roller 52 Another nest of lilac-leaf roller 53 Small green oak-moth 54 Nests of oak-leaf rolling caterpillars. 55 Nest of the nettle-leaf-rolling caterpillar . 56 Leaf-rolling caterpillars of the sorrel 57 Nests of the Hesperia malvoe, with caterpillar, chrysal 58 Nest of willow-leaf-roller 59 Ziczac caterpillar and nest ... 60 Cypress-spurge caterpillar 61 Cocoon of ditto on a branch . 62 Small caterpillar and moss cell of the same 63 Leaf nest of the caddis-worm 64 Reed nest of ditto .... 65 Aquatic nest of ditto .... 66 Shell nests of ditto, five figures 67 Stone nest of ditto .... 68 Sand nest of ditto, balanced with a stone . 69 Nest of ditto, balanced with straws 70 Caterpillar of goat-moth in a willow-tree 71 Winter nest of the goat-caterpillar . 72 Nest of goat-moth, raised to show the pupa 73 Eggs of the puss-moth 74 Rudiments of the cell of the puss-moth 75 Cell built by the larva of the puss-moth . 76 Ichneumon ..... 77 Magnified cells of Pyralis strigulalis 78 Nests of earth-mason caterpillars, two figures 79 Earth -mason caterpillars' nests, caterpillar and moth 80 Earth-mason caterpillars' nests, moth, &c., seven figur 81 Nests of the grubs of ephemera, two figures 82 Grub of ephemera 83 Nest of ephemera in holes of cossus . 84 Grub of the ant-lion, magnified 85 Trap of the ant-lion in different stages, two figures 86 Ant-lions' pitfalls in an experimenting box 87 Cases, &c., of the clothes-moth, and perfect moths 88 Caterpillar's tent upon the leaf of an elm 89 Tent of the caterpillar in different stages , 90 Tents and caterpillars, natural size, and magnified 91 Branch of the willow with seed-spikes . , 92 Aluff tents made of the above cotton 93 Muff-making caterpillar . . • . 94 Leaf of the monthly rose mined by caterpillars 95 Leaf of the dewberry bramble mined fied &c. ILLUSTRATIONS. XI Page 96 Leaf of the primrose mined ....... 207 97 Capricorn beetle rounding off the bark of a tree « . . 210 98 Mole-cricket, with outline of one of its hands .... 212 99 Nest of the Mole-cricket 213 100 Acrida verrucivora depositing her eggs . . . . .216 101 Artificial hive for observing the mason-ants .... 235 102 Vertical section for mason-ant's nest ..... 236 103 Contrivance of mason-ants to strengthen the building of their nest 237 104 Artificial hive for the wood-ant ...... 242 105 Portion of a tree, with chambers, &c., chiselled out by jet-ants . 245 106 Warrior-ant in the winged state . . . . . .255 107 White-ant queen distended with eggs ..... 258 108 Covered way and nest of the termites arborum". . . . 262 109 Section of the hill nest of the termites bellicosi . . . • 262 110 Hill nest of the termites bellicosi 262 111 Turi-et nests of white ants . . . . . . • . 263 112 Leg and pro-leg of a caterpillar, greatlv magnified . . . 268 113 Caterpillar of the goat-moUi. . ' 269 114 Interior structure of the cossus ...... 270 115 Side view of the silk tube 271 116 Section of silk tube, magnified . . . . . .271 117 Labium or lower lip of cossus ...... *271 118 Cocoons of the emperor-moth ...... 280 119 Cocoon of arctia villica ....... 282 120 Net-work cocoon 282 121 Nest of puss-moth, enclosing five cocoons .... 284 122 Winter nest of the social caterpillars of the bi'own-tail moth . 287 123 Winter nests of Porthesia chrysorrhjea ..... 288 124 Pendulous leaf-nests 289 125 Nest and order of marching of the processionary caterpillars . 290 126 Garden spider suspended by a thread from its spinneret . . 293 127 Spinneret of a spider magnified to show the spinnerules . . 294 128 Single thread of a spider, greatly magnified .... 295 129 Attached end of a spider's thread, magnified .... 295 130 Geometric net of the garden spider. ..... 312 131 Nests of the mason spider ....... 315 132 The spider, mygale cfementaria .,,... 315 133 The eyes, magnified ...... .315 134 Parts of the foot and claw, magnified ..... 315 135 Triple-clawed foot of a spider, magnified . .... 320 136 Small berry-shaped galls of the oak-leaf 323 137 Ovipositor of gall-fly, greatly magnified ..... 324 138 Gall-fly, and mechanism of ovipositor, greatly magnified . . 325 139 Bedeguar gall of the rose, produced by Cynips rosae . . . 327 140 One of the bristles of the bedeguar of the rose, magnified . . 328 141 Artichoke gall of the oak-bud, with gall-fly .... 330 142 Leafy gall of of dyer's broom 331 143 Semi-gall of the hawthorn 333 144 Woolly gall of the oak 334 145 Oak-apple galls, one cut open to show the vessels . . 335 146 Root galls of the oak 336 147 Woody gall on a willow branch 337 148 Currant gall of the catkins of the oak 337 Xll ILLUSTRATIOXS. the variou lis ribes ia2 ermiue on 149 Gall of the hawthorn weevil 150 A plant-louse, magnified 151 Galls produced on the leaves of the poplar, with of the insect, eleven figures 152 Leaf of the currant-bush, bulged out by the A\ 153 Shoot of the lime-tree contorted by the Aphis til 154 Pseudo-gall of the bramble . 155 Pseudo-galls of the hawthorn 156 Pseudo-gall on the Scotch fir 157 Ovipositor of the breeze-fly . 158 Grub of the breeze-fly, four figures 159 Fly, maggot, and grub of the ox breeze-fly 160 Bumps or wurbles produced on cattle 161 Viscera of the cossus . 162 Caterpillar of Vanessa urticse magnified . 163 Intestinal canals of the caterpillar, pupa, and butterfly 164 Ravages of the buff-tip caterpillar . 165 Encampment of the caterpillar of the small crab ... ... 166 Transformation of the Gamma moth 167 Saw-fly of the gooseberry 168 Numatus capreae on the osier, and Selandria aln 169 Transformations of the grain-moths 170 Transformations of the honeycomb-moths 171 Transformations of the cockchafer , 172 Wire-worm and click-beetle. 173 Zabrus gibbus, and Melolontha ruficornis. 174 Corn-weevil, magnified 175 Nut and apple tree beetles . 176 Bark mined in rays by beetle-grubs 177 Locust 178 Ovipositor and eggs of the crane-fly 179 Germination of a grain of wheat . . 180 Transformations of the wheat-fly . 181 The Hessian fly and the Markwick fly 182 Cheese-hoppers ..... 183 Transformations of Bibio hortulanus 184 Lace-winged fly and Syrphus 185 Breeding-cage ..... 186 Larvae-box and pocket collecting box 187 Water-net 188 Butterfly-net 189 Clap-net 190 Ring-net and net-forceps 191 French beetle-forceps and pliers . 192 Digger 193 Chip collecting-box .... 1 94 Setting-needles and brush, with the method of 195 Method of mounting small insects . 196 Setting-board frame .... settin the Siberian the alder insects forms INSECT ARCHITECTURE. CHAPTER I. I X T Pv D U C T I N. It can never be too strongly impressed upon a mind anxious for the acquisition of knowledge, that the commonest things by which we are surrounded are deserving of minute and careful attention. The most profound investigations of Philosophy are necessarily connected with the ordinary circumstances of our being, and of the world in which our every-day life is spent. With regard to our own existence, the pulsation of the heart, the act of respiration, the voIud- tary movement of our limbs, the condition of sleep, are among the most ordinary operations of our nature ; and yet how long were the wisest of men struggling with dark and bewildering speculations before they could oifer anything like a satisfactory solution of these phenomena, and how far are we still from an accurate and complete knowledge of them ! The science of Meteorology, which attempts to explain to us the philosophy of matters constantly before our eyes, as dew, mist, and rain, is dependent for its illus- trations upon a knowledge of the most complicated facts, such as the influence of heat and electricity upon the air ; and this knowledge is at present so imperfect, that even these common occurrences of the weather, which men have been observing and reasoning upon for ages, are by no means satisfactorily explained, or reduced to the precision that every science should aspire to. Yet, however difficult it may be entirely to comprehend the phenomena we dail}^ witness, everything in nature is full of instruction. Thus 2 INSECT ARCHITECTURE. the humblest flower of the field, although, to one whose curiosity has not been excited, and whose understanding has, therefore, remained uninformed, it may appear worth- less and contemptible, is valuable to the botanist, not only with regard to its place in the arrangement of this portion of the Creator's works, but as it leads his mind forward to the consideration of those beautiful provisions for the support of vegetable life, which it is the part of the physiologist to study and to admire. This train of reasoning is peculiarly applicable to the econoni}^ of insects. They constitute a very large and interesting part of the animal kingdom. They are every- where about us. The spider weaves his curious web in our houses ; the caterpillar constructs his silken cell in our gardens ; the wasp that hovers over our food has a nest not far removed from us, which she has assisted to build with the nicest art ; the beetle that crawls across our path is also an ingenious and laborious mechanic, and has some curious instincts to exhibit to those who will feel an interest in watching his movements ; and the moth that eats into our clothes has something to plead for our pity, for he came, like us, naked into the world, and he has destroyed our garments, not in malice or wantonness, but that he may clothe himself with the same wool which we have stripped from the sheep. An observation of the habits of these little creatures is full of valuable lessons, which the abundance of the examples has no tendency to diminish. The more such observations are multiplied, the more are w^e led forward to the freshest and the most delighful parts of knowledge ; the more do we learn to estimate rightly the extraordinary provisions and most abundant resources of a creative Provi- dence ; and the better do we appreciate our own relations with all the infinite varieties of Nature, and our dependence, in common with the ephemeron that flutters its little hour in the summer sun, upon that Being in whose scheme of existence the humblest as well as the highest creature has its destined purposes. "If you speak of a stone," sajs St. Basil, one of the Fathers of the Church, " if you speak of a fly, a gnat, or a bee, your conversation will be a sort of INTRODUCTION. 3 demonstration of His power whose band formed tliem, for the wisdom of the workman is commonly perceived in that which is of little size. He who has stretched out the heavens, and dng up the bottom of the sea, is also He who has pierced a passage through the sting of the bee for the ejection of its poison," If it be granted that making discoveries is one of the most satisfactory of hnman pleasures, then we may without hesitation affirm, that the study of insects is one of the most delightful branches of natural history, for it aftbrds peculiar facilities for its pursuit. These facilities are found in the almost inexhaustible variety which insects present to the curious observer. As a proof of the extraordinary number of insects within a limited field of observation, Mr. Stephens informs us, that in the short space of forty days, between the middle of June and the beginning of August, he found, in the vicinity of Ripley, specimens of above two thousand four hundred species of insects exclusive of caterpillars and grubs, — a number amounting to nearly a fourth of the insects ascertained to be indigenous. He further tells us, that, among these specimens, although the ground had, in former seasons, been frequently explored, there were about one hundred species altogether new, and not before in any collection which he had inspected, including several new genera; while many insects reputed scarce were in con- siderable plenty.* The localities of insects are, to a certain extent, constantly changing ; and thus the study of them has, in thi^ circumstance, as well as in their manifold abundance, a source of perpetual variety. Insects, also, which are ^^leiitiful one year, frequently become scarce, or disappear altogether, the next — a fact strikingly illustrated by the uncommon abundance, in 1826 and 1827, of the seven-spot lady-bird ( Coccinella septempunctata) , in the vicinity of London, though during the two succeeding summers this insect was comparatively scarce, while the small two-spot lady -bird (^Coccinella hipunctata) was plentiful. There is, perhaps, no situation in which the lover of nature and the observer of animal life may not find oppor- * Stephens' Illustrations, vol. i., p. 72, note. 4 INSECT AKCEUTECTURE. timities for increasing his store of facts. It is told of a state prisoner, nnder a cruel and rigorous despotism, that when he was excluded from all commerce with mankind, and was shut out from books, he took an interest and found consolation in the visits of a spider ; and there is no improbability in the story. The operations of that persecuted creature are among the most extraordinary exhibitions of mechanical ingenuity ; and a daily watching of the workings of its instinct would beget admiration in a rightly-constituted mind. The poor prisoner had abundant leisure for the speculations in which the spider's web would enchain his understanding. We have all of us, at one period or other of our lives, been struck with some singular evidence of contrivance in the economy of insects, which we have seen with our own eyes. Want of leisure, and probably want of knowledge, have prevented us from following up the curiosity which for a moment was excited. And yet some such accident has made men Naturalists, in the highest meaning of the term. Bonnet, evidently speak- ing of himself, saj^s, " I knew a naturalist, who, when he was seventeen years of age, having heard of the operations of the ant-lion, began by doubting them. He had no rest till he had examined into them ; and he verified them, he admired them, he discovered new facts, and soon became the disciple and the friend of the Pliny of France." * (Reaumur.) It is not the happy fortune of many to be able to devote themselves exclusively to the study of nature, unquestionably the most fascinating of human employments ; but almost every one one may acquire sufficient knowledge to be able to derive a high gratification from beholding the more common operations of animal life. His materials for contemplation are always before him. Some weeks ago we made an excursion to West Wood, near Shooter's Hill, expressly for the purpose of observing the insects we might meet with in the wood : but we had not got far among the bushes, when heavy rain came on. AVe imme- diately sought shelter among the boughs of some thick underwood, composed of oak, birch, and aspen; but we * Contemplation de la Nature, part ii. cli. 42. INTRODUCTIOX. 5 could not meet with a single insect, not even a gnat or a fly, slieltered under the leaves. Upon looking more nar- rowly, however, into the bushes which protected us, we soon found a variety of interesting objects of study. The oak abounded in galls, several of them quite new to us ; while the leaves of the birch and the aspen exhibited the curious serpentine paths of the minute mining caterpillars. When we had exhausted the narrow field of observation immediately around us, we found that we could considerably extend it, by breaking a few of the taller branches near us, and then examining their leaves at leisure. In this manner two hours glided quickly and pleasantly away, by which time the rain had nearly ceased ; and though we had been disappointed in our wish to ramble through the wood, we did not return without adding a few interesting facts to our previous knowledge of insect economy.* It will appear, then, from the preceding observations, that cabinets and collections, though undoubtedly of the highest use, are by no means indispensable, as the obsei-A^er of nature ma}^ find inexhaustible subjects of study in every garden and in every hedge. Nature has been profuse enough in affording us materials for observation, when we are prepared to look about us with that keenness of inquiry, which curiosity, the first step in the pursuit of knowledge, w^ill unquestionably give. Nor shall we be disappointed in the gratification which is thus within our reach. Were it no more, indeed, than a source of agreeable amusement, the study of insects comes strongly recommended to the notice of the well-educated. The pleasures of childhood are generally supposed to be more exquisite, and to contain less alloy, than those of riper jesus ; and if so, it must be because then everything appears new and dressed in fresh beauties : while in manhood, and old age, Avhatever has frequently recurred begins to wear the tarnish of decay. The study of nature affords us a succession of " ever new delights," such as charmed us in childhood, when everything had the attractions of novelty and beauty ; and * The original observations in this vohime which are marked liy tlie initials J, R., are by J. Rennie, A.M., A.L.S. 6 INSECT ARCHITECTURK. thus the mind of the naturalist may have its own fresh and vigorous thoughts, even while the infirmities of age weigh down the body. It has been objected to the stud}' of insects, as well as to that of Natural History in general, that it tends to with- draw the mind from subjects of higher moment ; that it cramps and narrows the range of thought ; and that it destroys, or at least weakens, the finer creations of the fimcy. Now, we should allow this objection in its fullest extent, and even be disposed to carry it further than is usually done, if the collecting of specimens only, or, as the French expressly call them, chips (echantiUons), be called a study. But the mere collector is not, and cannot be, justly considered as a naturalist ; and, taking the term naturalist in its enlarged sense, we can adduce some distinguished instances in opposition to the objection. Eousseau, for example, was passionately fond of the Linnaean botany, even to the driest minutias of its technicalities ; and yet it does not appear to have cramped his mind, or impoverished his imagination. If Eousseau, however, be objected to as an eccentric being, from whose pursuits no fair inference can be drawn, we give the illustrious example of Charles James Fox, and may add the Ucimes of our distinguished poets. Goldsmith, Thomson, Gray, and Darwin, who were all enthusiastic naturalists. We wish particularly to insist upon the example of Gray, because he was very partial to the study of insects. It may be new to many of our readers, who are fiimiliar with the ' Elegy in a Country Church-yard,' to be told that its author was at the pains to turn the characteristics of the Linnaian orders of insects into Latin hexametei's, the manuscript of which is still preserved in his interleaved copy of the ' Systema Naturae.' Further, to use the somewhat exaggerated words of Kirby and Spence, whose work on Entomology is one of the most instructive and pleasing books on the science. ' Aristotle among the Greeks, and Pliny the Elder among the Romans, may be denominated the fathers of Natural History, as well as the greatest philosophers of their day ; yet both these made insects a principal object of their attention : and in IXTRODUCTIOX. 7 more recent times, if we look abroad, what names greater than those of Eecli, Malpighi, Yallisnieri, Swammerdam. Leenwenhoek, Reainniir, Linnaeus, De Geer, Bonnet, and the Hubers ? and at home, what philosophers have done more honour to their country and to human nature than Ray, Willughby, Lister, and Derham ? Yet all these made the study of insects one of their most favourite pursuits." *• And yet this study has been considered, by those who have superficially examined the subject, as belonging to a small order of minds ; and the satire of Pope has been indiscriminately applied to all collectors, while, in truth, it only touches those who mistake the means of knowledge for the end : — " ! would the sons of men once think their eves And reason given them but to study Flies ! See Natiu-e, in some partial, narrow shape, And let the Autlior of the whole escape ; Learn but to trifle ; or, who most observe, To wonder at their Maker, not to serve."t Thus exclaims the Goddess of Dulness, sweeping into her net all those who study nature in detail. But if the matter were rightly appreciated, it would be evident that no part of the works of the Creator can be without the deepest interest to an inquiring mind ; and that a portion of creation which exhibits such extraordinary manifestations of design as is shown by insects must have attractions for the very highest understanding. An accurate knowledge of the properties of insects is of great importance to man, merely with relation to his own comfort and security. The injuries which they inflict upon us are extensive and complicated ; and the remedies which we attempt, by the destruction of those creatures, both insects, birds, and quadrupeds, who keep the ravages in check, are generally aggravations of the evil, because they are directed b}^ an ignorance of the economy of natuie. The little knowledge which we have of the modes by which insects may be impeded in their destruction of much that * Introduction to Entomology, vol. i. t Dunciad, book iv. 8 IXSECT ARCHITECTURE. is valuable to us, has probably proceeded from our contempt of their individual insignificance. The security of property has ceased to be endangered by quadrupeds of prey, and yet our gardens are ravaged by aphides and caterpillars. It is somewhat startling to affirm that the condition of the human race is seriously injured by these petty annoyances ; but it is perfectly true that the art and industry of man have not yet been able to overcome the collective force, the individual perseverance, and the complicated machiner}' of destruction which insects employ. A small ant, according to a most careful and philosophical observer, opposes almost invincible obstacles to the progress of civilization in many parts of the equinoctial zone. These animals devour paper and parchment ; they destroy every book and manuscript. Many provinces of Spanish America cannot, in consequence, show a written document of a hundred years' existence. " What development," he adds, " can the civilization of a people assume, if there be nothing to connect the present with the past — if the depositories of human knowledge must be constantty renewed— if the monuments of genius and wisdom cannot be transmitted to posterity ?" * Again, there are beetles which deposit their larvae in trees in such formidable numbers that whole forests perish beyond the jDower of remedy. The pines of the Hartz have thus been destroyed to an enormous extent ; and in North America, at one place in South Carolina, at least ninety trees in every hundred, upon a tract of two thousand acres, were swept away by a small black, winged bug. And yet, according to Wilson, the historian of American birds, the people of the United States were in the habit of destroying the red- headed woodpecker, the great enemy of these insects, because he occasionally spoilt an apple. f The same delight- ful writer and true naturalist, speaking of the labours of the ivory-billed woodpecker, says, "Mould it be believed that the larvae of an insect or fly, no larger than a gi-ain of rice, should silently, and in one season, destroy some thousand acres of pine-trees, many of them from two to * Humboldt, Voyage, lib. vii., cli, 20, t Amer. Ornith., i., p. 144, IXTRODUCTIOX. 9 three feet in diameter, and a Imndred and fifty feet high? In some places the whole woods, as far as you can see around you, are dead, stripped of the bark, their wintry- looking arms and hare trunks bleaching in the sun, and tumbling in ruins before every blast."* The subterraneous larva of some species of beetle has often caused a complete failure of the seed-corn, as in the district of Halle in 1812. t The corn-weevil, which extracts the flour from grain, leaving the husk behind, will destro}^ the contents of the largest storehouses in a very short period. The wire-worm and the turnip-fly are dreaded by every farmer. The ravages of the locust are too well known not to be at once recollected as an example of the formidable collective power of the insect race. The white ants of tropical countries sweep away whole villages with as much certainty as a fire or an inundation ; and ships even have been destroyed by these indefatigable republics. Our own docks and embankments have been threatened by such minute ravagers. The enormous injuries which insects cause to man may thus be held as one reason for ceasing to consider the study of them as an insignificant pursuit; for a knowledge of their structure, their food, their enemies, and their general habits, may lead, as it often has led, to the means of guarding against their injuries. At the same time we derive from them both direct and indirect benefits. The honey of the bee, the dye of the cochineal, and the web of the silk- worm, the advantages of which are obvious, may well be balanced against the destructive propensities of insects which are off'ensive to man. But a philosophical study of natural history will teach us that the direct benefits which insects confer upon us are even less import- ant than their general uses in maintaining the economy of the world. The mischiefs which residt to us from the rapid increase and the activity of insects are merely results of the very principle by which they confer upon us nrmi- berless indirect advantages. Forests are swept away by * Amer. Oriiith., iii., p. 21. t Blumenbacli ; sec also Insect Transforniatious, p. 2ol. 10 IXSECT ARCPIITECTURE. minute beetles ; but the same agencies relieve us from that extreme abundance of vegetable matter whicli would render the earth uninlmbitable were this excess not periodically destroyed. In hot countries, the great busi- ness of removing corrupt animal matter, which the vulture and the hya3na impeifectly perform, is eifected with certainty and speed by tlie myriads of insects that spring from the eggs deposited in every carcase by some fly seeking therein the means of life for her progeny. Destruc- tion and reproduction, the great laws of Nature, are carried on very greatly through the instrumentality of insects ; and the same principle regulates even the increase of parti- cular species of insects themselves. When aphides are so abundant that we know not how to escape their ravages, flocks of lady-birds instantly cover our fields and gardens to destroy them . Such considerations as these are thrown out to show that the subject of insects has a great philoso- phical importance — and what portion of the works of Nature has not? The habits of all God's creatures, whether they are noxious, or harmless, or beneficial, are worthy objects of our study. If they aftect ourselves, in our health or our possessions, whether for good or for evil, an additional impulse is naturally given to our desire to attain a knowledge of their properties. Such studies form one of the most interesting occupations which can engage a rational and inquisitive mind ; and, perhaps, none of the employments of human life are more dignified than the investigation and survey of the workings and the ways of Nature in the minutest of her productions. The exercise of that habit of observation which can alone make a naturalist —" an out-of-door naturalist," as Daines Barrington called himself — is well calculated to strengthen even the most practical and merely useful powers of the mind. One of the most valuable mental acquirements is the power of discriminating among things which differ in many minute points, but whose general similarity of ap- pearance usuall}^ deceives the common observer into a belief of their identity. The study of insects, in this point of view, is most peculiarly adapted for youth. According INTRODUCTION. 11 to our experience, it is exceedingly difficult for persons arrived at manhood to acquire this power of discrimination ; but, in early life, a little care on the part of the parent or teacher will render it comparatively easy. In this study the knowledge of things should go along with that of words. " If names perish," says Linnaeus, "the knowledge of things perishes also :"* and, without names, how can any one communicate to another the knowledge he has acquired relative to any particular fact, either of physio- logy, habit, utility, or locality ? On the other hand, mere catalogue learning is as much to be rejected as the loose generalizations of the despisers of classification and nomen- clature. To name a plant, or an insect, or a bird, or a quadruped rightly, is one step towards an accurate know^- ledge of it ; but it is not the knowledge itself. It is the means, and not the end, in natural history, as in every other science. If the bias of opening curiosity be properly directed, there is not any branch of natural history- so fascinating to youth as the study of insects. It is, indeed, a common practice in many families to teach children, from their earliest infancy, to treat the greater number of insects as if they were venomous and dangerous, and, of course, meriting to be destroyed, or at least avoided with horror. Associ- ations are by this means linked with the very appearance of insects, which become gradually more inveterate with advancing years; provided, as most frequently happens, the same system be persisted in, of avoiding or destroying almost every insect which is unlucky enough to attract observation. How much rational amusement and innocent pleasure is thus thoughtlessly lost; and how many dis- agreeable feelings are thus created, in the most absurd manner ! "In order to show that the study or (if the word be disliked) the observation of insects is peculiarly fasci- nating to children, even in their early infancy, we may refer to what we have seen in the family of a friend, who is partial to this, as well as to all the departments of natural history. Our friend's children, a boy and girl, were taught, * Nomina si pereant, pcrit et cognitio reniin. 12 INSECT ARCHITECTURE. from the moment they conld distinguish insects, to treat them as objects of interest and curiosity, and not to be afraid even of those which wore the most repulsive appear- ance. The little girl, for example, when just beginning to walk alone, encountered one day a large staph^'liuus (^Goerias olens? Stephexs; vulgo, th". deviVs coach-horse), w^hich she fearlessly seized, and did not quit her hold, though the insect grasped one of her lingers in his formi- dable jaws. The mother, who was by, knew enough of the insect to be rather alarmed for the con.^equences, though she prudently concealed her feelings from the child. She did well ; for the insect was not strong enough to break the skin, and the child took no notice of its attempts to bite her finger. A whole series of disagreeable associations with this formidable-looking family of insects was thus averted at the very moment when a different mode of acting on the part of the mother would have produced the contrary effect. For more than two yeaxs after this occur- rence the little girl and her brother assisted in adding numerous specimens to their father's collection, without the parents ever having had cause, from any accident, to repent of their employing themselves in this manner. The sequel of the little girl's history strikingly illustrates the position for which w^e contend. The child happened to be sent to a relative in the country, where she was not long in having carefully instilled into her mind all the usual antipathies against " everything that creepeth on the earth ;" and though she afterwards returned to her paternal home, UQ persuasion or remonstrance could ever again per- suade her to touch a common beetle, much less a staphy- linus, with its tail turned up in a threatening attitude, and its formidable jaws ready extended for attack or defence.* We do not wish that children should be encouraged to expose themselves to danger in their encounters with insects. The}'' should be taught to avoid those few which are really noxious — to admire all — to injure none. Tlie various beauty of insects —their glittering colours, their graceful forms —supplies an inexhaustible source of * J. R. in Mag. of Xatm-al History, vol. i., p. 334. INTRODUCTIOX. 1 3 attraction. Even the most formidable insects, both in appearance and reality, — the dragon-fly, which is perfectly harmless to man, and the wasp, whose sting every human being almost instinctively shuns, — are splendid in their appearance, and are painted with all the brilliancy of natural hues. It has been remarked, that the plumage of tropical birds is not superior in vivid colouring to what may be observed in the greater number of butterflies and moths.* "See," exclaims Linnt^eus, "the large, elegant painted wings of the butterfly, four in number, covered with delicate feathery scales ! With these it sustains itself in the air a whole day, rivalling the flight of birds and the brilliancy of the peacock. Consider this insect through the wonderful progress of its life, — how different is the first period of its being from the second, and both from the parent insect! Its changes are an inexplicable enigma to us : we see a green caterpillar, furnished with sixteen feet, feeding upon the leaves of a plant ; this is changed into a chrysalis, smooth, of golden lustre, hanging suspended to a fixed point, without feet, and subsisting without food ; this insect again undergoes another transformation, acquires wings, and six feet, and becomes a gay butterfly, sporting in the air, and living by suction upon the honey of plants. What has Nature produced more worthy of our admiration than such an animal, coming upon the stage of the world, and playing its part there under so many different masks ?" The ancients were so struck with the transformations of the butterfly, and its revival from a seeming temporary death, as to have considered it an emblem of the soul, the Greek word psyche signifying both the soul and a butterfly ; and it is for this reason that we find the butterfly intro- duced into their allegorical sculptures as an emblem of immortality. Trifling, therefore, and perhaps, contempt- ible, as to the unthinking may seem the study of a butter- fly, yet when we consider the art and mechanism displayed in so minute a structure, — the fluids circulating in vessels so small as alm.ost to escape the sight— the beauty of the wings and covering — and the manner in which each part is * Miss Jermyn's Butterfly Collector, p. 11. 14 INSECT ARCHITECTUKE. adapted for its peculiar functions, — we cannot but be struck with wonder and admiration, and allow, with Paley, that " the production of beauty was as much in the Creator's mind in painting a butterfly as in giving symmetry to the human form." A collection of insects is to the true naturalist what a collection of medals is to the accurate student of history. The mere collector, who looks only to the shining wings of the one, or the green rust of the other, derives little knowledge from his pursuit. But the ' cabinet of the naturalist becomes rich in the most interesting subjects of contemplation, when he regards it in the genuine spirit of scientific inquiry. What, for instance, can be so delightful as to examine the wonderful variety of structure in this portion of the creation ; and, above all, to trace the beauti- ful gradations by which one species runs into another? Their differences are so minute, that an unpractised eye would proclaim their identity ; and yet, when the species are separated, and not very distantl}", they become visible even to the common observer. It is in examinations such as these that the naturalist finds a delight of the highest order. While it is thus one of the legitimate objects of his study to attend to minute differences of structure, form, and colouring, he is not less interested in the investigation of habits and economy ; and in this respect the insect world is inexhaustibly rich. We find herein examples of instinct to parallel those of all the larger animals, whether the}^ are solitary or social ; and innumerable others besides, altogether unlike those manifested in the superior depart- ments of animated nature. These instincts have various directions, and are developed in a more or less striking manner to our senses, according to the force of the motive by which they are governed. Some of their instincts have for their object the preservation of insects from external attack ; some have reference to procuring food, and involve man}- remarkable stratagems ; some direct their social economy, and regulate the condition under which they live together either in monarchies or republics, their colonizations, and their migrations; but the most powerful instinct which INTRODUCTIOX. 15 belongs to insects lias regard to the preservation of their species. ^Ye find, accordingly, that as the necessity for this preservation is of the ntmost importance in the economy of nature, so for this especial object man}^ insects, whose offspring, whether in the egg or the larva state, are peculiarly exposed to danger, are endued with an almost miraculous foresight, and with an ingenuity, perseverance, and unconquerable industry, for the purpose of avoiding tliose dangers, which are not to be paralleled even by the most singular efforts of human contrivance. The same ingenuity which is employed for protecting either eggs, or caterpillars and grubs, or pupse and chiysalides, is also exercised by many insects for their own preservation against the changes of temperature to which they are exposed, or against their natural enemies. Many species employ those contrivances during the period of their hyber- nation, or winter sleep. For all these purposes some dig holes in the earth, and form them into cells ; others build nests of extraneous substances, such as bits of wood and leaves ; others roll up leaves into cases, which they close with the most curious art; others build a house of mud, and line it with the cotton of trees, or the petals of the most delicate flowers ; others construct cells, of secretions from their own bodies ; others form cocoons, in which they undergo their transformation ; and others dig subter- raneous galleries, which, in their complexity of arrange- ment, in solidity, and in complete adaptation to their purposes, vie with the cities of civilised man. The con- trivances b}^ which insects effect these objects have been accurately observed and minutely described, by patient and philosophical inquirers, who knew that such employ- ments of the instinct with which each species is endowed by its Creator offered the most valuable and instructive lessons, and opened to them a wide field of the most de- lightful study. The construction of their habitations is certainly among the most remarkable peculiarities in the economy of insects ; and it is of this subject that we pro- pose to treat under the general name, wdiicli is sufficiently applicable to our purpose, of Insect Architecture. IG INSECT ARCHITECTURE. In the descriptions which we shall give of Insect Archi- tecture, we shall employ as few technical words as pos- sible ; and such as we cannot well avoid, we shall explain in their places : but, since our subject chiefly relates to the reprodiiction of insects, it may be useful to many readers to introduce here a brief description of the changes which they undergo. It was of old believed that insects were produced spon- taneously by putrefying substances ; and Yirgil gives the details of a process for creating a swarm of bees out of the carcase of a bull : but Kedi, a celebrated Italian naturalist, proved by rigid experiments that they are always, in such cases, hatched from eggs previously laid. Most insects, indeed, lay eggs, though some few are viviparous, and some propagate both ways. The eggs of insects are very various in form, and seldom shaped like those of birds. We Maffnifiod f>?i:s <>f a, Genmrtra aTmilluta ; h, of an unknown water insect; c, of the lacquevnidth ; (/.of a oadrtis-flv {Phriiqavea atrata) ; />, of red nnderwing moth {Catocaia nwpta); f, of Puntia Brassica; g, of the CUtden Nonpareil niuth. have here figured those of several species, as they appear under the microscope. When an insect first issues from the egg, it is called by naturalists larva, and, popularly, a caterpillar, a grub, or a maggot. The distinction, in popular language, seems to be, that caterpillars are produced from the eggs of moths or butterflies; grubs from the eggs of beetles, bees, wasps, &c.; IXTRODUCTTON. 17 and maggots (which are without feet) from blow-flies, house-flies, cheese-flies, &c., though this is not very rigidly adhered to in common parlance. Maggots are also some- times called worms, as in the instance of the meal-worm ; but the common earth-worm is not a larva, nor is it by modem naturalists ranked among insects. There are, however, certain lai-vse, as those of the Cicada, the crickets, the water boatsman (Nofonedci), the cock- roach, &c., which resemble the perfect insects in form, excepting that they are destitute of wings ; but in the pupa state these appear in a rudimentary condition, at least in such species as have wings in the mature stage of existence. a, Ametabolous Pupa of Cicada; />, Caterpillar of tussock moth (Lariafascelina); c, larva of the poplar beetle {Chrysomela popuU),; d, larva of Siiiex ; e, larva of the common gnat. The pupa3 are active and eat. Insects, the larvae and pupae of which are so similar to the adults, are termed Ametabolous (a, without, j^ieraftoKy], change) ; those the larvse of which undergo changes of a marked character, Metaholous (Insecta ametabola and Insecta metabola, Burmeister). Larva3 are remarkably small at first, but grow rapidly. The full-grown caterpillar of the goat moth (Cossus ligni- perda) is thus seventy-two thousand times heavier than c 18 INSECT ARCHITECTURE. when it issues from the egg ; and the maggot of the blow- fl}'- is, in twenty-four hours, one hundred and fifty-five times heavier than at its birth. Some hirvge have feet, othefs are without ; none have wings. They cannot pro- jDagate. They feed voraciously on coarse substances ; and as they increase in size, which they do very rapidly, they cast their skins three or four times. In defending them- selves from injury, and in preparing for their change by the construction of secure abodes, they manifest great ingenuity and mechanical skill. The figures on the preceding page exemplify various forms of insects in this stage of their existence. AVhen larvas are full grow^n, they cast their skins for the last time, undergo a complete change of form, excepting in the case of ametabolous larvae, cease to eat, and remain nearly motionless. The inner skin of the larva now becomes converted into a membranous or leathery covering, which wraps the insect closely up like a mummy : in this a, Pupa ut a water-beetle illijiirophitus) ; b, pupa of Si±inx Ligustri. condition it is termed Pupa, from its resemblance 'to an infant in swaddling bands. Nympha, or nymph, is another term given to insects in this stage ; * moreover from the pupa3 of many of the butterflies appearing gilt as if with gold, the Greeks called them Chrysalides, and the Komans Aurelice, and hence naturalists frequently call a pupa chrysalis, even when it is not gilt. AVe shall see, as we * Generally to ametabolous pupae. INTRODUCTtOX. 19 proceed, the curious contrivances resorted to for protecting insects in this helpless state. After a certain time, the insect which has remained in its pupa-case, like a mass of jelly without shape, is graduallj^ preparing for its final change, when it takes the form of a perfect insect. This state was called by Linnaeus Imago, because the insect, having thrown off its mask, becomes a perfect image of its species. Of some, this last portion of their existence is very short, others live through a year, and some exist for longer periods. They feed lightly, and never increase in size. The chief object of all is to perpetuate their species, after which the greater number quickly die. It is in this state that they exercise those remarkable instincts for the preservation of their race, which are exhibited in their preparations for the shelter of their eggs, and the nourishment of their larvae. The follow- ing are examples of insects in the imago, or perfect state. Insects in the Imago or perfect state. a, Xemoptej-yx coa. Leach.— &, Myrmeleon formicalytix, Fabuicius Fabkicius.— ti, A''epa cinerea, Lin's jeus. Hesi)eria comma. ( 20 ) CHAPTER II. STRUCTURES FOR TROTECTIXG EGGS. — MASON- WASPS ; MASOX- BEES; MINIXG-BEES. The provisions which are made by the different species of insects for protecting their eggs, aj^pear in many cases to be admirably proportioned to the kind of danger and destruction to which they may be exposed. The eggs themselves, indeed, are not so liable to depredation and injury as the young brood hatched from them ; for, like the seeds of plants, they are capable of withstanding greater degrees both of heat and cold than the insects which produce them. According to the experiments of Spallanzani, the eggs of frogs that had been exposed to various degrees of artificial heat were scarcely altered in their productive powers by a temperature of 111° of Fahrenheit, but they became corrupted after 133^. He tried the same experiment upon tadpoles and frogs, and found they all died at 111°. Silkworms died at a tem- perature of 108^, Avhile their eggs did not entirely cease to be fertile till 144^ • The larvge of flesh-flies perished, while the eggs of the same species continued fertile, at about the same comparative degrees of heat as in the pre- ceding instances. Intense cold has a still less effect upon eggs than extreme heat. Spallanzani exposed the eggs of silkworms to an artificial cold 23^ below zero, and yet, in the subsequent spring, they all produced caterpillars. Insects almost invariably die at the temperature of 14°, that is, at IS'' below the freezing point.* The care of insects for the protection of their eggs is not entirely directed to their preservation in the most favourable temperature for being hatched, but to secure them against the numerous enemies which would attempt their destruc- * See Spallanzani's Tracts, by Dalycll, vol. i. INTRODUCTIOX. 21 tion ; and, above all, to protect the grubs, when they are first developed, from those injuries to which they are peculiarly exposed. Their prospective contrivances for accomplishing these objects are in the highest degree curious. Most persons have more or less acquaintance with the hives of the social species of bees and wasps ; but little is generally known of the nests constructed by the solitary species, thougli in many respects these are not inferior to the others in displays of ingenuity and skill. We admire the social bees, labouring together for one common end, in the same way that we look with delight upon the great division of labour in a well-ordered manufactory. As in a cotton-mill some attend to the carding of the raw material, some to its formation into single threads, some to the gathering these threads upon spindles, others to the union of many threads into one, — all labouring with invariable precision because they attend to a single object ; — so do we view with delight and wonder the successive steps by which the hive-bees bring their beautiful work to its completion, — striving, by individual efforts, to accom- plish their general task, never impeding each other by useless assistance, each taking a particular department, and each knowing its own duties. We may, however, not the less admire the solitary wasp or bee, who begins and finishes every part of its destined work ; just as we admire the ingenious mechanic who perfects something useful or ornamental entirely by the labour of his own hands, — ■ whether he be the patient Chinese carver, who cuts the most elaborately-decorated boxes out of a solid piece of ivory, or the turaer of Europe, who produces every variety of elegant form by the skilful application of the simplest means. Our island abounds with many varieties of solitary wasps and bees ; and their nests may therefore be easily dis- covered by those who, in the proper seasons, are desirous of observing the peculiarities of their architecture. 22 INSECT ARCHITECTURE. Masox-Wasps. In September, 1828, a common species of solitary mason- wasp ( Odi/nerus, Late.) was observed by ns (J. K.) on the east wall of a house at Lee, in Kent, ver}" busy in exca- vating a hole in one of the bricks, about five feet from the groiTiKl. Whether there might not have been an accidental hole in the brick, before the wasp commenced her labours, is unknown, as she had made considerable progress in the work when first observed; but the brick was one of the hardest of the yellow sort made in this neighbourhood. The most remarkable circumstance in the process of hewing into the brick was the care of the insect in removing to a distance the fragments which from time to time she suc- ceeded in detaching. It did not appear to suit her design to wear dowii the brick, particle by particle, as the furniture Odynerus.—K atura] size. beetle (^Anohium pertinax) does in making its pin-hole galleries in old wood. Our wasp-architect, on the contrary, by means of her strong tranchant-iooi\\Q^ jaws, severed a piece usually about the bigness of a mustard-seed. It might have been supposed that these fragments would have been tossed out of the hole as the work proceeded, without further concern ; as the mole tosses above ground the earth which has been cleared out of its subterranean gallery. The wasp was of a different opinion ; for it was possible that a heap of brick chips, at the bottom of the wall, might lead to the discovery of her nest by some of her enemies, particular] 3^ by one or other of the numerous tribe of what are called ichneumoi -flies. This name is given to tliem, from the similarity of their habit of destroying eggs, to that of the little animal which proves so formidable an enemy to the multiplication of the crocodile of Egypt. They ma}^ be also denominated cwcAoo-flies, because, like that bird, they thrust MASON-BEES. 23 their egg into the nest of another species. These flies are continually prowling about and prying into every corner, to find, by stealth, a nidus for their eggs. It might have been some such consideration as this which induced the wasp to carry off the fragments as they were successively detached. That concealment was the motive, indeed, was proved; for one of the fragments which fell out of the hole by accident, she immediately sought for at the bottom of the wall, and carried off like the rest. It was no eas}^ Mandibles— Jaws of Mason- Wasp.— Greatly nuignified. matter to get out one of the fragments, as may readily be conceived when the size of the insect is compared with that of the entrance, of which this ( J|) is the exact size, as taken from the impression of a bit of dough upon the hole when fi.nished. It was only by seizing the fragment with her jaws, and retreating backwards, that the matter could be accomplished ; though, after the interior of the excavation was barely large enough to admit of her turning round, she more than once attempted to make her exit head-foremost, b)ut always unsuccessfully. The weight of the fragments removed did not appear to impede her flight, and she generally returned to her task in about two or three minutes. Within two days the excavation was completed ; but it required two other days to line it with a coating of clay, to deposit the eggs, two in number, and, no doubt, to imprison a few live spiders or caterpillars, for the young when hatched — a process which was first observed by Ray and Willughby,* but which has since been frequently ascer- * Rav, Hist. Insect., 254. 24 INSECT ARCHITECTURE. tained. In the present instance, this peculiarity was not seen ; bnt the little architect was detected in closing up the entrance, which was formed of a la3'er of clay more than double the thickness of the interior lining. In November following, we hewed away the brick around this nest, and found the whole excavation was rather less than an inch in depth. Notwithstanding all the precautions of the careful parent to conceal her nest, it was found out by one of the cuckoo flies ( Tachina larvanmi .?) — probabl}^ a common species very similar to the house-fly, but rather larger, which deposited Cuckoo-Fly.— (Tac/Mna taruarunif)— Xatural size. an egg there ; and the grub hatched from it, after devouring one of the wasp-grubs, formed itself a cocoon (a), as did Mason- Wasp's Nest and Coeouns. — About one-thii-ii tlio natural size. the other undevoured grub of the wasp (6). Both awaited the return of summer to change into winged insects, burst their cerements, and proceed as their parents did. Another mason wasp (Ochjnerus murarius, Latr.), diflfer- Mdson-W a?.\).—((klijncnis vinrariit.'i).—'S a.t\\ri\\ size. ing little in appearance from the former, may often be seen MASOX-BEES. 25 frequenting sandy banks exposed to the sun, and construct- ing its singular burrows. The sort of sand-bank which it selects is hard and compact ; and though this may be more difficult to penetrate, the walls are not liable to fall down upon the little miner. In such a bank, the mason-wasp bores a tubular gallery two or three inches deep. The sand upon which Reaumur found some of these wasps at work was almost as hard as stone, and yielded with difficulty to his nail ; but the wasps dug into it with ease, having recourse, as he ascertained, to the ingenious device of moistening it by letting fall two or three drops of fluid from their mouth, which rendered the mass ductile, and the separation of the grains easy to the double pickaxe of the little pioneers. When this wasp has detached a few grains of the moistened sand, it kneads them together into a pellet about Nests, &c., of Mason-Wasps.— About half the natural size. a, The tower of the nest; h, the entrance after the tower is removed ; c, the cell ; d, the cell, with a roll of caterpillars prepared for the larva. the size of one of the seeds of a gooseberry. With the first pellet which it detaches, it lays the foundation of a round tower, as an outwork, immediately over the mouth of its nest. Every pellet which it afterwards carries off from the interior is added to the wall of this outer round tower, which advances in heiurht as the hole in the sand increases 26 INSECT ARCHITECTURE. in depth. Every two or three minutes, however, during these operations, it takes a short excursion, for the purpose, probably, of replenishing its store of fluid wherewith to moisten the sand. Yet so little time is lost, that Eeaumur has seen a mason-wasp dig in an hour a hole the length of its body, and at the same time build as much of its round tower. For the greater part of its height this round tower is perpendicular ; but towards the summit it bends into a curve, corresponding to the bend of the insect's body, which in all cases of insect architecture, is the model followed. The pellets which form the walls of the tower are not very nicely joined, and numerous vacuities are left between them, giving it the appearance of filligree-Avork. That it should be thus slightly built is not surprising, for it is intended as a temporary structure for protecting the insect Avhile it is excavating its hole ; and as a pile of materials, well arranged and ready at hand, for the com- pletion of the interior building,^ — in the same way that workmen make a regular pile of bricks near the spot where they are going to build. This seems, in fact, to be the main design of the tower, which is taken do^Ti as ex- peditiously as it had been reared. Eeaumur thinks that, by piling in the sand which has previouly been dug out, the wasp intends to guard his progeny for a time from being exposed to the too violent heat of the sun ; and he has even sometimes seen that there were not sufficient materials in the tower, in which case the wasp had recourse to the rubbish she had thrown out after the tower was completed. By raising a tower of the materials which she excavates, the wasp produces the same shelter from external heat as a human creature would avIio chose to inhabit a deep cellar of a high house. She further protects her progeny from the ichneumon-fly, as the engineer constructs an outwork to render more difficult tlie approach of an enemy to the citadel. Eeaumur has seen this indefatigable enemy of the wasp peep into the mouth of the tower, and then retreat, apparently frightened at the depth of the cell which he was anxious to invade. The mason-wasp does not furnish the cell she has thus MASON-BEES. 27 constructed with pollen* and honey, like the solitary bees, but with living caterpillars, and these always of the same species — being of a green colour, and without feet. She fixes the caterpillars together in a spiral column : they cannot alter their position, although they remain alive. They are an easy prey to their smaller enemy ; and when the grub has eaten them all up, it spins a case, and is transformed into a pupa, which afterwards becomes a wasp. The number of caterpillars which is thus found in the lower cavity of the mason-wasp's nest is ordinarily from ten to twelve. The mother is careful to lay in the exact quantity of provision which is necessary to the growth of the grub before he quits his retreat. He works through his store till his increase in this state is perfected, and he is on the point of undergoing a change into another state, in which he requires no food. The careful purveyor, cruel indeed in her choice of a supply, but not the less directed by an unerring instinct, selects such caterpillars as she is conscious have completed their growth, and will remain thus imprisoned without increase or corruption till their destroyer has gradually satisfied the necessities of his being. "All that the worm of the wasp," says Eeamur, " has to do in his nest, from his birth to his transformation, is to eat." There is another species of wasp which does not at once enclose in its nest all the sustenance which its larva will require before transformation, but which from time to time imprisons a living caterpillar, and when that is consumed, opens the nest and introduces another.* Mason-Bees. It would not be easy to find a more simple, and, at the same time, ingenious specimen of insect architecture than the nests of those species of solitary bees which have been justly called mason-bees (^Megachile, Latreille). Eeaumur, who was struck by the analogies between the proceedings of insects and human arts, first gave to bees, wasps, and * The prolific powder of flowers. t Bonnet, Contemplation, &e. 1. xii. c. 41. 28 INSECT ARCHITECTURE. caterpillars lliose names which indicate the character of their labours ; and which, though they ma}^ be considered a little fanciful, are at least calculated to arrest the attention. The nests of mason-bees are constructed of various materials; some with sand, some with earth mixed with chalk, and some with a mixture of earthy substances and wood. On the north-east wall of Greenwich Park, facing the road, and about four feet from the ground, we discovered (J. E.), December lOtli, 1828, the nest of a mason bee, formed in the perpendicular line of cement between two bricks. Externally there was an irregular cake of dry mud, precisely as if a handful of wet road-stuff had been taken from a cart-rut and thrown against the wall ; though, upon Mason-Bee.— (.4rti/ioj)/trtra ?-ei«sa).— Natural size. closer inspection, the cake contained more small stones than usually occur in the mud of the adjacent cart-ruts. AVe should in fact have passed it by without notice had there not been a circular hole on one side of it, indicating the perforation of some insect. Tliis hole was found to be the orifice of a cell about an inch deep, exactly of tlie form and size of a lady's tliimble, finel}^ polished, and of the colour of plaster-of-Paris, but stained in various places with yellow. MASOX-BEES. 29 This cell was empty ; but, upon removing the cake of mud, we discovered another cell, separated from the former by a partition about a quarter of an inch thick, and in it a living bee, from Avhich the preceding figure was drawn, and which, as we supposed, had just changed from the pupa to the winged state, in consequence of the im- common mildness of the weather. The one which had occupied the adjacent cell had, no doubt, already dug its way out of its prison, and would probably fall a victim to the first frost. Cells of a Masuu-Bee {Anthophora j-e(Msa).— Oiie-lhinl the natural size. Our nest contained only two cells — perhaps from there not being room between the bricks for more. An interesting account is given by Eeaumur of another mason-bee (Magachile muraricC), not a native of Britain, se- lecting earthy sand, grain by grain ; her gluing a mass of these together with saliva, and building with them her cells from the foundation. But the cells of the Greenwich Park nest were apparently composed of the mortar of the brick wall ; though the external covering seems to have been constructed as Eeaumur describes his nest, with the occa- sional addition of small stones. About the middle of May, 1829, we discovered the mine from which all the various species of mason-bees in the vicinity seemed to derive materials for their nests. (J. E.)" It was a bank of brown clay, facing the east, and close by the margin of the river Eavensbourn, at Lee, in Kent. The frequent resort of the bees to this spot attracted the attention of some workmen, who, deceived by their resem- blance to wasps, pointed it out as a wasps' nest ; though they were not a little surprised to see so numerous a colony 30 INSECT ARCHITECTURE. at this early season. As the bees had clng a hole in the bank, where they were incessantly entering and reappearing, we were of opinion that they were a peculiar sort of the social earth-bees (^Bomli). On approaching the spot, how- ever, we remarked that the bees were not alaimed, and manifested none of the irritation usual in such cases, the consequence of jealous affection for their young. This led us to observe their operations more minutely ; and we soon discovered that on issuing from the hole each bee carried out in its mandibles a piece of clay. Still supposing that they were social earth-bees, we concluded that they were busy excavating a hollow for their nest, and carrying off the refuse to prevent discovery. The mouth of the hole was overhung, and partly concealed, by a large pebble. This we removed, and widened the entrance of the whole, intend- ing to dig down and ascertain the state of the operations ; but we soon found that it was of small depth. The bees, being scared away, began scooping out clay from another hole about a yard distant from the first. Upon our with- drawing a few feet from the first hole, they returned thither in preference, and continued assiduously digging and remov- ing the clay. It became obvious, therefore, from their thus changing place, that they were not constructing a nest, but merely quarrying for clay as a building material. By catching one of the bees ( Osmia bicornis') when it was loaded with its burden, we ascertained that the cla}^ was not only carefully kneaded, but was also more moist than the mass from which it had been taken. The bee, therefore, in pre- paring tlie pellet, which was nearly as large as a garden- pea, had moistened it with its saliva, or some similar fluid, to render it, we may suppose, more tenacious, and better fitted for building. The reason of their digging a hole, instead of taking clay indiscriminately from the bank, appeared to be for the purpose of economizing their saliva, as the weather was dry, and the clay at the surface was parched and hard. It must have been this circumstance which induced them to prefer digging a hole, as it were, in concert, though each of them had to build a separate nest. The distance to which they carried the clay was probably MASOX-BEES. 31 considerable, as tliere was no wall near, in the direction they all flew towards, upon which they could build ; and in the same direction also, it is worthy of remark, they could have procured much nearer the very same sort of clay. What- ever might be the cause of their preference, we could not but admire their extraordinary industry. It did not require more than half a minute to knead one of the pellets of clay ; and, from their frequent returns, probably not more than five minutes to carry it to the nest, and apply it where wanted. From the dryness of the weather, indeed, it was indispensable for them to work rapidly, otherwise the clay could not have been made to hold together. The extent of the whole labour of forming a- single nest may be im- agined, if we estimate that it must take several hundred pellets of clay for its completion. If a bee work fourteen or fifteen hours a-day, therefore, carrying ten or twelve pellets to its nest every hour, it will be able to finish the structure in about two or three days ; allowing some hours of extra time for the more nice workmanship of the cells in which the eggs are to be deposited, and the young grubs reared. That the construction of such a nest is not a merely agreeable exercise to the mason-bee has been sufficiently proved by M. Du Hamel. He has observed a bee (Megachile muraria) less careful to perform the necessary labour for the protection of her offspring than those we have described, but not less desirous of obtaining this protection, attempt to usurp tlie nest which another had formed. A fierce battle was invariably the consequence of this attempt ; for the tme mistress would never give place to the intruder. The motive for the injustice and the resistance was an in- disposition to further labour. The trial of strength was probably, sometimes, of as little use in establishing the right as it is amongst mankind ; and tlie proper owner, exhausted by her efforts, had doubtless often to surrender to the dishonest usurper. The account which Reaumur has given of the operations of this class of bees differs considerably from that which we have here detailed ; from the species being different, or 32 INSECT ARCHITECTURE. from his bees not having been able to procure moist clay. On the contraiy, sand was the chief material used by the mason-bees (^Megachile muraria') ; which they had the patience to select from the walks of a garden, and knead into a paste or mortar, adapted to their building. They had consequently to expend a much greater quantity of saliva than our bees (^Osmia bicurnis), which worked with moist clay. Eeaumur, indeed, ascertained that everj^ individual gi-ain of sand is moistened previous to its being joined to the pellet, in order to make it adhere more effectually. The tenacity of the mass is, besides, rendered stronger, he tells us, by adding a proportion of earth or garden-mould. In this manner, a ball of mortar is formed, about the size of a small shot, and carried off to the nest. \Yhen the sti'uc- ture of this is examined, it has all the appearance externally of being composed of earth and small stones or gravel. The ancients, who were by no means accurate naturalists, having observed bees carrying pellets of earth and small stones, supposed that they employed these to add to their weight, in order to steady their flight when impeded by the wind. The nests thus constructed appear to have been more durable edifices than those which have fallen under our ob- servation ; — for Eeaumur says they were harder than many sorts of stone, and could scarcely be penetrated with a knife. Ours, on the contrary, do not seem harder than a piece of sun-baked clay, and by no means so hard as brick. One circumstance appeared inexplicable to Eeaumur and his friend Du Hamel, who studied the operations of these insects in concert. After taking a portion of sand from one part of the garden-walk, the bees usually took another portion from a spot almost twent}^ and sometimes a hundred paces off, though the sand, so far as could be judged by close examination, was precisely the same in the two places. We should be disposed to refer this more to the restless character of the insect than to any difference in the sand. We have observed a wasp paring the outside of a plank, for materials to form its nest ; and though the j^lank was as uniform in the qualities of its surface, na}^ probably more MASON-BEES. 33 SO than the sand could be, the wasp fidgeted about, nibbling a fibre from one, and a fibre from another poi'tion, till enough was procured for one load. In the same way, the whole tribe of wasps and bees flit restlessly from flower to flower, not unfrequently revisiting the same blossom, again and again, within a few seconds. It appears to us, indeed, to be far from improbable, that this "very restlessness and irritability may be one of the springs of their unceasing industry. By observing, with some care, the bees w^iich we found digging the clay, we discovered one of them ( Osmia hicornis) at work upon a nest, about a gunshot from the bank. The place it had chosen was the inner wall of a coal-house, facing the south-west, the brick-work of which was but roughly finished. In an upright interstice of half an inch in width, between two of the bricks, we fomid the little architect assiduously building its walls. The bricklayer's mortar had either partly fallen out, or been removed by the bee, who had commenced building at the lower end, and did not build downwards, as the social wasps construct their cells. The very different behaviour of the insect here, and at the quarry, struck us as not a little remarkable. When digging and preparing the clay, our approach, however near, produced no alarm ; the work went on as if we had been at a distance ; and though we were standing close to the hole, this did not scare away any of the bees upon their arrival to procure a fresh load. But if we stood near the nest, or even in the way b}' which the bee flew to it, she turned back or made a Avide circuit immediately, as if afraid to betray the site of her domicile. We even observed her turning back, when we were so distant that it could not reasonably be supposed she was jealous of us ; bait probably she had detected some prowling insect depredator, tracking her flight with designs upon her provision for her future progeny. We imagined we could perceive not a little art in her jealous caution, for she would alight on the tiles as if to rest herself; and even when she had entered the coal- house, she did not go directly to her nest, but again rested D S4 INSECT ARCHITECTURE. on a slielf, and at other times pretended to examine several crevices in the wall, at some distance from the nest. But when there was nothing to alarm her, she flew directly to the spot, and began eagerly to add to the building. It is in instances such as these, which exhibit the adapta- tion of instinct to circumstances, that our reason finds the greatest difficult}- in explaining the governing principle of the minds of the inferior animals. The mason-bee makes her nest by an invariable rule ; the model is in her mind, as it has been in the mind of her race from their first crea- tion : they have learnt nothing bj^ experience. But the mode in which they accomplish this task varies according to the situations in which they are placed. They appear to have a glimmering of reason, employed as an accessary and instrument of their instinct. The structure, when finished, consisted of a wall of clay 1 2 3 Cells of Mason- Bees, built, in the first and second figures, bj' Osmia bicornis between bricks, and in tlie third, by Megachile muraria in the fluting of an old pilaster.— About lialt the natural size. supported by two contiguous bricks, enclosing six chambers, within each of which a mass of pollen, rather larger than a cherry-stone, was deposited, together with an egg, from which in due time a grub was hatched. Contrary to what has been recorded by preceding naturalists with respect to other mason -bees, we found the cells in this instance quite parallel and peipendicular ; but it may also be remarked, that the bee itself was a species altogether different from the one which we have described above as the AnthopJiora retiisa, and agreed with the figure of the one we caught quarrying the clay — ( Osmia iiconm). MASON-BEES. 35 There was one circumstance attending the proceedings of this mason-bee which struck as not a little, though we could not explain it to our own satisfaction. Every time she left her nest for the purpose of procuring a fresh supply of materials, she paid a regular visit to the blossoms of a lilac-tree which grew near. Had these blossoms afforded a supply of pollen, with which she could have replenished her cells, we could have easily understood her design ; but the pollen of the lilac is not suitable for this purpose, and that she had never used it was proved by all the pollen in the cells being yellow, whereas that of the lilac is of the same pale, purple colour as the flowers. Besides, she did not return immediately from the lilac-tree to the building, but always went for a load of clay. There seemed to us, therefore, to be only two ways to explain the circumstance : —she must either have applied to the lilac-blossoms to obtain a refreshment of honey, or to procure glutinous materials to mix with the clay. When employed upon the building itself, the bee ex- hibited the restless disposition peculiar to most hymeno- pterous* insects ; for she did not go on with one particular portion of her wall, but ran about from place to place every time she came to work. At first, when we saw Mason-Bee and Xesl, from Ed lumur. her running from the bottom to the top of her building, we naturally imagined that she went up for some of the bricklayer's mortar to mix with her own materials ; but upon minutely examining the walls afterwards, no lime * The fifth order of Liniia3u,s ; insects with four transparent veined winj^s. 36 INSECT ARCHITECTURE. could be discovered in tlieir structure similar to that whidi was apparent in the nest found in the wall of Greenwich Park. Eeaumur mentions another sort of mason-bee, which selects a small cavity in a stone, in which she forms her nest of garden-mould moistened with gluten, and afterwards closes the whole with the same material. Minixg-Bees. A ver}^ small sort of bees (Andrencp) , many of them not larger than a house-fly, dig in the ground tubulai' galleries little wider than the diameter of their own bodies. Samouelle says, that all of them seem to prefer a southern aspect ; but we have found them in banks facing the east, and even the north. Immediately above the spot where we have de- scribed the mason-bees quarrying the clay, we observed several holes, about the diameter of the stalk of a tobacco- Cell of Mining-Bee (.Andrena^.—Ahout half the natural size. pipe, into which those little bees were seen passing. The clay here was very hard ; and on passing a straw into the hole as a director, and digging down for six or eight inches, a very smooth circular gallery was found, tenninating in a thimble-shaped horizontal chamber, almost at right angles to the entrance and nearly" twice as wide. In this chamber there was a ball of bright 3'ellow pollen, as round as a garden pea, and rather larger, upon which a small white grub was feeding ; and to which the mother bee had been adding, as she had just entered a minute before with her thighs loaded with iiollen. That it was not the male, the load of pollen determined ; for the male has no appa- ratus for collecting or transporting it. The whole labour of digging the nest and providing food for the young is MINING-BEES. 37 performed by the female. The females of the solitary bees have no assistance in their tasks. The males are idle ; and the females are unprovided with labourers, such as the queens of the hive command. Keaumur mentions that the bees of this sort, whose operations he had observed, piled up at the entrance of their galleries the earth which they had scooped out from the interior ; and when the grub was hatched, and pro- jDcrly provided with food, the earth was again employed to close up the passage, in order to prevent the intrusion of ants, ichneumon-flies, or other depredators. In those which we have observed, this was not the case ; but every species differs from another in some little pecu- liarity, though they agree in the general principles of their operations. ( 38 ) CHAPTER III. CARPENTER-BEES ; CARPEXTER- WASPS ; UPHOLSTERELl-BEES. Carpenter-Bees. Among the solitary bees are several British species, which come under that class called carpenter-bees by M. Reaumur, from the circumstance of their working in wood, as the mason-bees work in stone. We have frequently witnessed the operations of these ingenious little workers, who are particularly partial to posts, palings, and the wood-work of houses which has become soft by beginning to decay. AVood actually decayed, or affected by dry-rot, they seem to reject as unfit for their purposes ; but they make no objections to any hole previously drilled, provided it be not too large; and, like the mason-bees, they not unfre- quently take possession of an old nest, a few repairs being all that in this case is necessary. When a new nest is to be constructed, the bee proceeds to chisel sufficient space for it out of the w^ood with her jaws. We say her, because the task in this instance, as in most others of solitary bees and wasps, devolves solely upon the female, the male taking no concern in the affair, and probably being altogether ignorant that such a work is going forward. It is, at least, certain that the male is never seen giving his assistance, and he seldom, if ever, approaches the neighbourhood. The female carpenter-bee has a task to perform no less arduous than the mason-bee ; for though the wood may be tolerably soft, she can only cut out a very small portion at a time. The successive portions which she gnaws off may be readily ascertained by an observer, as she carries them away from the place. In giving the history of a mason-wasp (Odynerus'), at page 22, we remarked the care with which she carried to a distance CARPENTER-BEES. 39 little fragments of brick, wliicli she detached in the pro- gress of excavation. We have recently watched a pre- cisely similar procedure in the instance of a carpenter- bee forming a cell in a wooden post. (J. E.) The only difference was, that the bee did not fly so far away with her fragments of wood as the wasp did ; but she varied the direction of her flight every time : and we could observe, that after dropping the chip of wood which she had carried off, she did not return in a direct line to her nest, but made a circuit of some extei^t before wheeling round to go back. On observing the proceedings of this carpenter-bee next day, we found her coming in with balls of pollen on her thighs ; and on tracing her from the nest into the adjacent garden, we saw her visiting eveiy flower which was likely to yield her a supply of pollen for her future progeny. This was not all ; we subsequently 8aw her taking the direction of the clay quarry frequented by the mason-bees, as we have mentioned in page 29, where we recognised her loading herself with a pellet of clay, and carrying it into her cell in the wooden post. We observed her alternating this labour for several days, at one time carrying clay, and at another joollen ; till at length she completed her task, and closed the entrance with a barricade of clay, to prevent the intrusion of any insectivorous depredator, who might make prey (^f her 3'oung ; or of some prying parasite, who might introduce its own eggs into the nest she had taken so much trouble to construct. Some days after it was finished, we cut into the post, and exposed this nest to view. It consisted of six cells of a somewhat square shape, the wood forming the lateral walls ; and each was separated from the one adjacent by a partition of clay, of the thickness of a playing card. The wood was not lined with any extraneous substance, but was worked as smooth as if it had been chiselled by a joiner. There were five cells, arranged in a very singular manner — two being almost horizontal, two perpendicular, and one oblique. The depth to which the wood was excavated in this 40 TXSECT ARCHITECTUJIE. instance was considerably less tlian what we have ob- served in other species which dig perpendicular galleries several inches deep in posts and garden-seats ; and they are inferior in ingenuity to the carpentr}^ of a bee de- <'£\ UiSaj-^j Cells of Carpenter-Bees,.excavated in an old post. In fig. A tbe cells contain the j'oung grubs; in fig. B the cells are empty. Both figures are shown in section, and about half their natural size. scribed by Eeaumur (^Xylocopa violacea), which has not been ascertained to be a native of Britain, though a single indigenous species of the genus has been doubtingiy mentioned, and is figured by Kirby and Spence, in their valuable ' Monographia.' If it ever be found here, its large size and beautiful violet-coloured wings will render mistakes impossible. The violet carpenter-bee usually selects an upright piece of wood, into which she bores obliquely for about an inch ; and then, changing the direction, works perpendicularly, and parallel to the sides of the wood, from twelve or fifteen inches, and half an inch in breadth. Sometimes the bee is contented with one or two of these excavations ; at other times, when the wood is adapted to it, she scoops out three or four — a task which sometimes requires several weeks of incessant labour. The tunnel in the wood, however, is only one pait of the work ; for the little architect has afterwards to divide the whole into cells, somewhat less than an inch in depth. It is necessary, for the proper growth of her progeny, that each should be separated from the other, and be CARPENTEK-BEES. 41 provided with adequate food. She knows, most exactly, the quantity of food which each gmb will require during its growth ; and she therefore does not hesitate to cut it off from any additional supply. In constructing her cells, she does not employ clay, like the bee which we have men- tioned above, but the sawdust, if we may call it so, which A represents a part of an espalier prop, tunnelled in several places by the violet carpenter-bee : the stick is split, and shows the nests and passages by which they are approached. B, a portion of tlie prop, half the natural size. C, a piece of tliin stick, pierced by the carpenter-bee, and split, to show the nests. D, Perspective view of one of the partitions. E, Carpenter-bee {Xylocopa violacea). F, Teeth of the carpenter-bee. greatly inagnitied ; a, the upper side ; b, the lower side. she has collected in gnawing out the gallery. It would not, therefore, have suited her design to scatter this about, as our carpenter-bee did. The violet-bee, on the contraiy, collects her giiawings into a little store-heap for future use, at a short distance from her nest. She proceeds thus : — ■ 42 INSECT ARCHITECTURE. At the bottom of her excavation she deposits an egg, and over it fills a space nearly an inch high with the pollen of flowers, made into a paste with honey. She then covers this over with a ceiling composed of cemented sawdust, Avhich also serves for the floor of the next chamber above it. For this purpose she cements round a wall a ring, of wood-chips taken from her store-heap ; and within this ring forms another, gradually contracting the diameter till she has constructed a circular plate, about the thickness of a crown-piece, and of considerable hardness. This plate of course exhibits concentric circles, somewhat similar to the annual circles in the cross section of a tree. In the same manner she proceeds till she has completed ten or twelve cells ; and then she closes the main entrance with a barrier of similar materials. Let us compare the progress of this little joiner with a human artisan — one who has been long practised in his trade, and has the most perfect and complicated tools for his assistance. The bee has learnt nothing by prac- tice ; she makes her nest but once in her life, but it is then as complete and finished as if she had made a thousand. She has no pattern before her — but the Architect of all things has impressed a plan upon her mind, which she can realize without scale or compasses. Her two sharp teeth are the only tools with which she is provided for her laborious woik ; and yet she bores a tunnel, twelve times the length of her own body, with greater ease than the workman who bores into the earth for water, with his apparatus of augurs adapted to every soil. Her tunnel is clean and regular ; she leaves no chips at the bottom, for she is provident of her materials. Further, she has an exquisite piece of joinery to perform when her ruder labour is accomplished. The patient bee works her rings from the circumference to the centre, and she produces a shelf, united with such care with her natural glue, that a number of fragments are as solid as one piece. The violet carpenter-bee, as may be expected, occupies several weeks in these complicated labours : and during that period she is gradually depositing her eggs, each of CARPENTER-BEES. 43 which is successively to become a grub, a pupa, and a perfect bee. It is obvious, therefore, as she does not lay all her eggs in the same place — as each is separated from the other by a laborious process — that the egg which is first laid will be the earliest hatched ; and that the first perfect insect, being older than its fellows in the same tunnel, will strive to make its escape sooner, and so on of the rest. The careful mother provides for this contingency. She makes a lateral opening at the bottom of the cells ; for the teeth of the young bees would not be strong enough to pierce the outer wood, though they can remove the cemented rings of sawdust in the interior. Eeaumur observed these holes, in several cases ; and he further noticed another external opening opposite to the middle cell, which he supposed was formed, in the first instance, to shorten the distance for the removal of the fragments of wood in the lower half of the building. That bees of similar habits, if not the same species as the violet-bee, are indigenous to this country, is proved by Grew, who mentions, in his ' Earities of Gresham College,' having found a series of such cells in the middle of the pith of an elder branch, in which they were placed lengthwise, one after another, with a thin boundary between each. As he does not, however, tell us that he was ac- quainted with the insect which constructed these, it might as probably be allied to the Ceratina aJbilalris, of which Spinola has given so interesting an account in the ' Annales du Museum d'Histoire Xaturelle ' (x. 286). This noble and learned naturalist tells us, that one evening he per- ceived a female ceratina alight on the branch of a bi amble, partly withered, and of which the extremity had been broken ; and, after resting a moment, suddenly disappear. On detaching the branch, he found that it was perforated , and that the insect was in the very act of excavating a nidus for her eggs. He forthwith gathered a bundle of branches, both of the bramble and the wild-rose, similarly perforated, and took them home to examine them at leisure. Upon inspection, he fuund that the nests were furnished 44 INSECT ARCHITECTURE. like those of the same tribe, with balls of pollen kneaded with honey, as a provision for the grubs. The female ceratina selects a branch of the bramble or wild-rose which has been accidentally broken, and digs into the pith only, leaving the wood and bark nntouched. Her mandibles, indeed, are not adapted for gnawing wood ; and, accordingly, he found instances in which she could not finish her nest in branches of the wild-rose, where the pith was not of sufiicient diameter. Tlie insect usually makes her perforation a foot in depth, and divides this into eight, nine, or even twelve cells, each about five lines long, and separated by partitions formed by the gnawings of the pith, cemented by honey, or some similar glutinous fluid, much in the same manner with the xylocopa violacea, which we have already described. Carpenter-Wasps. As there are mason-wasps similar in economy to mason- bees, so are there solitaiy carpenter- wasps which dig gal WJJ^'i^ Al'-'' A B represent sections of old wooden posts, with the cells ot the carpenter-wasp. In fig. A tlie young grubs are shown feeding <)n the insects placed there for their support by the parent wasp. The cells in flg. B contain cocoons. V, carpenter-wasp, natural size. D, cocoon of a carpenter- wasp, composed of sawdust and wings of insects. leries in timber, and partition them out into several cells by means of the gnawings of the wood which they have detached. This sort of wasp is of the genus Eumenes. The wood selected is generally such as is soft, or in a state of UPIIOLSTEREE-BEES. 45 decay ; and the liole wliicli is dug in it is mncli less neat and regular tlian tliat of the carpenter-bees, while the division of the chambers is nothing more than the rubbish produced during the excavation. The provision which is made for the grub consists of flies or gnats piled into the chamber, but without the nice order remarkable in the spiral columns of green caterpillars provided by the mason- wasp {Odynerus murarius). The most remarkable circumstance is, that in some of the species, when the grub is about to go into the pupa state, it spins a case (a cocoon), into which it interweaves the wings of the flies whose bodies it has previously devoured. In other species, the gnawings of the wood are employed in a similar manner. Upholsterer-Bees. In another part of this volume we shall see how certain caterpillars construct abodes for themselves, by cutting oif portions of the leaves or bark of plants, and uniting them by means of silk into a uniform and compact texture ; but this scarcely appears so wonderful as the prospective labours of some species of bees for the lodgment of their progeny. AVe allude to the solitary bees, known b}^ the name of the leaf-cutting bees, but which may be denomi- nated more generally upholsterer-bees, as there are some of them which use other materials beside leaves. One. species of our little upholsterers has been called the poppy-bee (Osmia papaveris, Late.), from its selecting the scarlet petals of the poppy as tapestry for its cells. Kirby and Spence express their doubts whether it is indigenous to this country : we are almost certain that we have seen the nests in Scotland. (J. E.) At Largs, in Ayrshire, a beautiful sea-bathing village on the Firth of Clyde, in July, 1814, we found in a footpath a great number of the cylindrical perforations of the poppy-bee. Ec'aumur remarked that the cells of this bee which he found at Bercy, were situated in a northern exposure, contrary to what he had remarked in the mason-bee, which prefers the south. The cells at Largs, however, were on an elevated 46 INSECT ARCHITECTURE. bank, facing the south, near Sir Thomas Brisbane's obser- vatory. With respect to exposure, indeed, no certain rule seems applicable ; for the nests of mason-bees which we found on the wall of Greenwich Park faced the north-east, and we have often found carpenter-bees make choice of a similar situation. In one instance, we found carpenter-bees working indifferently on the north-east and south-west side of the same post. As we did not perceive any heaps of earth near the holes at Largs, we concluded that it must either have been carried off piecemeal when they were dug, or that they were old holes reoccupied (a circumstance common with bees), and that the rubbish had been trodden down by passengers. Eeaumur, who so minutely desciibes the subsequent operations of the bee, sa3"s nothing respecting its excavations. One of these holes is about three inches deep, gradually widening as it descends, till it assumes the form of a small Florence flask. The interior of this is rendered smooth, uniform, and polished, in order to adapt it to the tapestry with which it is intended to be hung, and which is the next step in the process. The material used for tapestry by the insect upholsterer is supplied by the flower-leaves of the scarlet field-poppy, from which she successively cuts off small pieces of an oval shape, seizes them between her legs, and conveys them to the nest. She begins her work at the bottom, which she overlays with three or four leaves in thickness, and the sides have never less than two. When she finds that the piece she has brought is too large to fit the place intended, she cuts off what is superfluous, and carries awa}^ the shreds. By cutting the fresh petal of a poppy With a pair of scissors, we may perceive the difiiculty of keeping the piece free from wrinkles and shrivelling ; but the bee knows how to spread the pieces which she uses as smooth as glass. AVhen she has in this manner hung the little chamber all around with this splendid scarlet tapestry, of which she is not sparing, but extends it even beyond the entrance, she then fills it with the pollen of flowers mixed with honey, to the height of about half an inch. In this magazine UPHOLSTERER-ISEES. 47 of provisions for her future progeny she lays an egg, and over it folds down the tapestry of poppy-petals from above. The upper part is then filled in with earth ; but Latreille says, he has observed more than one cell constructed in a single excavation. This may account for Eeaumur's de- scribing them as sometimes seven inches deep ; a circum- stance which Latreille, however, thinks very surprising. It will, perhaps, be impossible ever to ascertain, beyond a doubt, whether the tapestry-bee is led to select the bril- liant petals of the poppy from their colour, or fiom any other quality they may possess, of softness or of warmth, for instance. Reaumur thinks that the largeness, united with the flexibility of the poppy-leaves, determines her choice. Yet it is not improbable that her eye may be gratified by the appearance of her nest ; that she may possess a feeling of the beautiful in colour, and may look with complacency upon the delicate hangings of the apart- ment which she destines for her offspring. Why should not an insect be supposed to have a glimmering of the value of ornament ? How can we pronounce, from our limited notion of the mode in which the inferior animals think and act, that their gratifications are wholly bounded by the positive utility of the objects which surround them ? Why does a dog howl at the sound of a bugle, but because it offends his organ of hearing ? — and why, therefore, may not a bee feel gladness in the brilliant hues of her scarlet drapery, because they are grateful to her oi-gans of sight ? All these little creatures work, probably, with more neat- ness and finish than is absolutely essential for comfort ; and this circumstance alone would imply that they have some- thing of taste to exhibit, which produces to them a plea- surable emotion. The tapestry-bee is, however, content with ornamenting the interior only of the nest which she forms for her progeny. She does not misplace her embellishments with the error of some human artists. She desires security as well as elegance; and, therefore, she leaves no external traces of her operations. Hers is not a mansion rich with columns and friezes without, but cold and unfurnished 48 INSECT ARCHITECTUKE. \^dtlim, like tlie desolate palaces of Venice. She covers her tapestry quite round with the common earth; and leaves her eggs enclosed in their poppy-case with a cer- tainty that the outward show of her labours will attract no plunderer. The poppy-bee may be known by its being rather more than a third of an inch long, of a black colour, Btudded on the head and back with reddish-grey hairs ; the belly being grey and silky, and the rings margined with grey above, the second and third having an impressed transversal line. A species of solitarj^ bee (^Anthidium manicafum, Fabricius), by no means uncommon with us, fonns a nest of a peculiarly interesting structure. Kirby and Spence say, that it does not excavate holes, but makes choice of the cavities of old trees, key -holes, and similar localities ; yet it is highlj^ probable, we think, that it may sometimes scoop out a suitable cavity when it cannot find one ; for its mandibles seem equally capable of this, with those of any of the car- penter- or mason- bees. Be this as it may, the bee in question having selected a place suitably sheltered from the weather, and from the intrusion of depredators, proceeds to form her nest, the exterior walls of which she forms of the wool of pubescent plants, such as rose-campion {^Lychiis coronaria), the quince {Pyrus cydonid), cats-ears (Stachys hmafa), &c. *' It is very pleasant," says Mr. AYhite, of Selborne, " to see ^^dth what address this insect strips off the down, lunning from the top to the bottom of the branch, and shaving it bare with all the dexterity of a hoop-shaver. AY hen it has got a vast bundle, almost as large as itself, it flies away, holding it secure between its chin and its fore-legs." * The material is rolled up like a libbon ; and we possess a spe- cimen in which one of these rolls still adheres to a rose- campion stem, the bee having been scared away before obtaining her load. * Naturalist's Cakndar. p. 100. UPHOLSTERER-BEES. 49 The manner in wliicli the cells of the nest are made seems not to be very clearly understood. M. Latreille says, that, after constructing her nest of the down of quince-leaves, she deposits her eggs, together with a store of paste, formed of the pollen of flowers, for nourishing the grubs. Kirby and Spence, on the other hand, tell us, that " the parent bee, after having constructed her cells, laid an egg in each, and filled them with a store of suitable food, plasters them with a covering of vermiform masses, appa- rently composed of honey and pollen; and having done this, aware, long before Count Eumford's experiments, what materials conduct heat most slowly," she collects the down from woolly plants, and " sticks it upon the plaster that covers her cells, and thus closely envelops them with a warm coating of down, impervious to ever}" change of temperature." "From later observations," however, they are " inclined to think that these cells may possibly, as in the case of the humble-bee, be in fact formed by the larva previously to becoming a pupa, after having eaten the provision of pollen and honey with which the parent bee had surrounded it. The vermicular shape, however, of the masses with which the cases are surrounded, does not seem easily reconcileable with this supposition, unless they are considered as the excrement of the larva." * AVhether or not this second explanation is the true one, we have not the means of ascertaining ; but we are almost certain the first is incorrect, as it is contrary to the regular procedure of insects to begin with the interior part of any structure, and work outwards. We should imagine, then, that the down is first spread out into the fonn required, and afterwards plastered on the inside to keep it in form, when probably the grub spins the vermicular cells previous to its metamorphosis. It ^ might prove interesting to investigate this more minutely ; and as the bee is by no means scarce in the neighbourhood of London, it might not be difScult for a careful observer to witness all the details of this singular architecture. Yet we have repeatedly endeavoured, but * Introduction to Entomology, vol. i. p. 435, 5th edit. E 50 ixsECT akchitecturp:. without success, to watch the bees, when loaded with down, to their nests. The bee may be readily known from its congeners, bf its being about the size of the hive-bee, but more broad and flattened, blackish-brown above, with a row of six yellow or white spots along each side of the rings, very like the rose-leaf cutter, and having the belly covered Avith yellowish -brown hair, and the legs fringed witli long hairs of a rather lighter colour. A common bee belonging to the family of upholsterers is called the rose-leaf cutter (^Afegachile ceiituncularis, Latr.). The singularly ingenious habits of this bee have long attracted the attention of naturalists ; but the most interest- ing description is given by Reaumur. So extraordinary does the construction of their nests appear, that a French gar- dener having dug up some, and believing them to be the work of a magician, who had placed them in his garden with evil intent, sent them to Paris to his master, for advice as to what should be done hj way of exorcism. On applying to the Abbe Xollet, the owner of the garden was soon per- suaded that the ne.sts in question were the work of insects ; and M. Reaumur, to wliom they were subsequently sent, found them to be the nests of one of the upholsterer-bees, and probably of the rose-leaf cutter, though the nests in question were made of the leaves of the mountain ash (^Pyrm aucuparia). The rose-leaf cutter makes a cylindrical hole in a beaten pathway, for the sake of more consolidated earth (or in the cavities of walls or decayed wood), from six to ten inches deep, and does not throw the eaith dug out from it into a heap, like the Andrense.* In this she constructs several cells about an inch in length, shaped like a thimble, and made of cuttings of leaves (not petals), neatly folded together, the bottom of one thimble-shaped cell being inserted into the mouth of the one below it, and so on in succession. It is interesting to observe the manner in which this bee procures the materials for forming the tapestry of * See p. oG. UPHOLSTERE R-BEES. 51 her cells. The leaf of the rose-tree seems to be that which she prefers, though she sometimes takes other sorts of leaves, particularly those with serrated margins, such as the birch, the perennial mercury (^Mercurialis perennis), mountain- ash, &c. She places herself upon the outer edge of the leaf which she has selected, so that its margin may pass between her legs. Turning her head towards the point, she com- mences near the footstalk, and with her mandibles cuts out a circular piece with as much expedition as we could do with a pair of scissors, and with more accuracy and neatness than could easily be done by us. As she proceeds, she keeps the cut portion between her legs so as not to Kose-leaf cutter Bees, and Nest lined with rose-leaves. impede her progress ; and using her body for a trammel, as a carpenter would say, she cuts in a regular curved line. As she supports herself during the operation upon the portion of the leaf which she is detaching, it must be obvious, when it is nearly cut oft', that the weight of her body might tear it away, so as to injure the accuracy of its 52 INSECT ARCHITECTUKE. curvilineal shape. To prevent any accident of this kind, as soon as she suspects that her weight might tear it, she poises herself on her wings, till she has completed the incision. It has been said, by naturalists, that this ma- noeuvre of poising herself on the wing, is to prevent her falling to the ground, when the piece gives way; but as no winged insect requires to take any such precaution, our explanation is probably the true one. With the piece which she has thus cut out, held in a bent position perpendicularly to her body, she flies off to her nest, and fits it into the interior with the utmost neatness and ingenuity ; and, without emplojdng any paste or glue, she trusts, as Eeaumur ascertained, to the spring the leaf takes in drying, to retain it in its position. It requires from nine to twelve pieces of leaf to form one cell, as they are not always of precisely the same thickness. The interior surface of each cell consists of three pieces of leaf, of equal size, narrow at one end, but gradually widening at the other, where the width equals half the length. One side of each of the pieces is the serrated margin of the leaf from which it was cut, and this margin is always placed outer- most, and the cut margin innermost. Like most insects, she begins with the exterior, commencing with a layer of tapestry, which is composed of three or four oval pieces, larger in dimensions than the rest, adding a second and a third layer proportionately smaller. In forming these, she is careful not to place a joining opposite to a joining, but with all the skill of a consummate artificer, laj^s the middle of each piece of leaf over the margins of the others, so as b}^ this means both to cover and strengthen the junctions. By repeating this process, she sometimes forms a fourth or a fifth layer of leaves, taking care to bend the leaves at the narrow extremity or closed end of the cell, so as to bring them into a convex shape. AYhen she has in this manner completed a cell, her next business is to replenish it with a store of honey and pollen, which, being chiefly collected from thistles, forms a beautiful rose-coloured conserve. In this she deposits a single egg, and then covers in the opening with three pieces of leaf, so UPHOLSTERER-BEES. 53 exactly circular, that a pair of compasses could not define their margin with more accuracy. In this manner the industrious and ingenious upholsterer proceeds till the whole gallery is filled, the convex extremity of the one fitting into the open end of the next, and serving both as a basis and as the means of strengthening it. If, by any accident, the labour of these insects is interrupted or the edifice deranged, they exhibit astonishing perseverance in setting it again to rights. Insects, indeed, are not easily forced to abandon any work which they may have begun. The monkish legends tell us that St. Francis Xavier, walking one day in a garden, and seeing an insect, of the Mantis genus, moving along in its solemn way, holding up its two fore legs, as in the act of devotion, desired it to sing the praises of God. The legend adds that the saint imme- diately heard the insect carol a fine canticle with a loud emphasis. We want no miraculous voice to record the wonders of the Almighty hand, when we regard the insect world. The little rose-leaf cutter, pursuing her work with the nicest mathematical art — using no artificial instruments to form her ovals and her circles — knowing that the elastic property of the leaves will retain them in their position — making her nest of equal strength throughout, by the most rational adjustment of each distinct part — demands from us something more than mere wonder ; for such an exercise of instinctive ingenuity at once directs our admiration to the great Contriver, who has so admirably proportioned her knowledoie to her necessities. ( 54 ) CHAPTEE IV. CARDER-BEES ; HUMBLE-BEES ; SOCIAL-WASRS. The bees and wasps, whose ingenious architecture we have already examined, are solitary in their labours. Those we are about to describe live in society. The perfection of the social state among this class of insects is ceitainly that of the hive-bees. They are the inhabitants of a large city, where the arts are carried to a higher excellence than in small districts enjoying little communication of intelligence. But the bees of the villages, if we may follow up the parallel are not without their interest. Such are those which are called carder-bees and humble-bees. Carder-Bees. The nests of the bees which Eeaumur denominates carders {Bomhus muscorum, Latr.) are b}^ no means uncommon, and are well worth the study of the naturalist. During the hay harvest, they are frequently met with by mowers in the open fields and meadows ; but they may sometimes be discovered in hedge-banks, the borders of copses or among moss-grown stones. The description of the mode of building adopted by this bee has been copied by most of our writers on insects from Eeaumur ; though he is not a little severe on those who write without having ever had a single nest in their possession, ^\e have been able to avoid such a reproach ; for we have now before us a very complete nest of carder-bees, which differs from those described by Eeanmur, in being made not of moss, but withered grass. With this exception, we find that his account agrees accurately with our own observations. (J. R.) The carder-bees select for their nests a shallow excava- tion about half a foot in diameter ; but when they cannot CARDER-BEES. 55 find one to suit their purpose, they undertake the Herculean task of digging one themselves. They cover this hollow with a dome of moss — sometimes, as we have ascertained, of withered grass. They make use, indeed, of whatever materials may be within their reach ; for they do not attempt to bring anything from a distance, not even when they are deprived of the greater portion by an experimental naturalist. Their only method of transporting materials to r'fl^^i.^?^ vjz-if Fig. A represents two Carder-bees heckling moss for their uests. B, exterior view of the nest of the carder-bee. the building is by pushing them along the ground — the bee, for that purpose, working backwards, with its head turned from the nest. If there is only one bee engaged in this labour, as usually happens in the early spiing, when a nest is founded by a solitary female who has outlived the winter, she transports her little bundles of moss or grass by successive backward pushes, till she gets them home. 56 IXSECT ARCHITECTURE. In .the latter part of the season, when the hive is populous and can afford more hands, there is an ingenious division of this labour. A file of bees, to the number sometimes of half a dozen, is established, from the nest to the moss or grass which they intend to use, the heads of all the file of bees being turned from the nest and towards the material. The last bee of the file lays hold of some of the moss with her mandibles, disentangles it from the rest, and having carded it with her fore-legs into a sort of felt or small bundle, she pushes it under hei* body to the next bee, wdio passes it in the same manner to the next, and so on till it is brought to the border of the nest, — in the same way as we sometimes see sugar-loaves conveyed from a cart to a warehouse, by a file of porters throwing them from one to another. The elevation of the dome, which is all built from the interior, is from four to six inches above the level of the field. Beside the moss or grass, they frequently employ coarse wax to form ihe ceiling of the vault, for the pur- pose of keeping out rain, and preventing high winds from destroying it. Before this finishing is given to the nest, we have remarked, that on a fine sunshiny day the upper portion of the dome was opened to the extent of more than an inch, in order, we suppose, to forward the hatching of the eggs in the interior ; but on the approach of night this was carefully covered in again. It was remarkable that the opening which we have just mentioned was never used by the he^s for either their entrance or their exit from the nest, though they were all at work there, and, of course, would have found it the readiest and easiest passage. But they invariably made their exit and their entrance through the covert- way or gallery which opens at the bottom of the nest, and, in some nests, is about a foot long and half an inch wide. This is, no doubt, intended for concealment from field-mice, pole-cats, wasps, and other depredators. On removing a portion of the dome and bringing the interior of the structure into view, we find little of the architectural regularity so conspicuous in the combs of a common bee-hive ; instead of this symmetr}', there are CARDER-BEES. 57 only a few egg-sliaped, dark-coloured cells, placed some- what irregularly, but approacliing more to the horizontal than to the vertical position, and connected together with small amorphous* columns of brown wax. Sometimes there are two or three of these oval cells placed one above another, without anything to unite them. These cells are not, however, the workmanship of the old bees, but of their young grubs, who spin them when they are about to change into nymphs. But, from these cases, when they are spun, the enclosed insects have no means of escaping, and they depend for their liberation on the old bees gnawing off the covering, as is done also by ants in the same circumstances. The instinct with which they know the precise time when it is proper to do this is truly wonderful. It is no less so, that these cocoons are by no means useless when thus untenanted, for they subsequently serve for honey-pots, and are in- deed the only store-cells in the nest. For this purpose the edge of the cell is repaired and strengthened with a ring of wax. The true breeding-cells are contained in several amor- phous masses of brown-coloured wax, varying in dimensions, but of a somewhat flat and globular shape. On opening Broediug-Cells. any of these, a number of eggs or grubs are found, on whose account the mother bee has collected the masses of wax, which also contain a supply of pollen moistened with honey, for their subsistence. The number of eggs or grubs found in one spheroid of wax varies from three to thirty, and the bees in a whole * Shapeless. 58 IXSECT ARCHITECTURE. nest seldom exceed sixty. There are three sizes of bees, ol which the females are the largest; but neither these nor the males are, as in the case of the hive-bee, exempt from labour, the females, indeed, always found the nests, since they alone survive the winter, all the rest perishing with cold. In each nest, also, are several females, that live in harmony together. The carder-bees may be easily distinguished from their Interior views of Carder-Bee's Nest. congeners (of the same genus), by being not unlike the coloui' of the withered moss with which they build their nests, having the fore part of their back a dull orange, and hinder part ringed with different shades of greyish yellow. They are not so large as the common humble-bee (Bomhus terrestris, Latr.), but rather shorter and thicker in the body than the common hive-bee (^Ajyis melUfica.) LAPLDAIIY-BEES. — HUMBLE-BEES. 59 Lapidary-Bees. A bee still more common, perhaps, than the carder is the orange-tailed bee, or lapidary (Bomhus lapidaria), readily known by its general black colour and reddish orange tail. It builds its nest sometimes in stony ground, but prefers a heap of stones such as are gathered off grass fields or are piled up near quarries. Unlike the carder, the lapidary carries to its nest bits of moss, which are very neatly arranged into a regular oval. ' These insects associate in their labours ; and they make honey with great industr3% The individuals of a nest are more numerous than the carders, and likewise more pertinaciously vindictive. About two years ago Ave discovered a nest of these bees at Compton- Bassett, in Wiltshire, in the centre of a heap of limestone rubbish ; but owing to the brisk defensive waifare of their legionaries, we could not obtain a view of the interior. It was not even safe to approach within many yards of the place ; and we do not exaggerate when we say that several of them pursued us most pertinaciously about a quarter of a mile. (J. E.) Humble-Bees. The common humble-bee {Bomhus terrestris) is precisely similar in its economy to the two preceding species, with this difference, that it forms its nest underground like the common wasp, in an excavated chamber, to which a winding passage leads, of from one to two feet, and of a diameter sufficient to allow of two bees passing. The cells have no covering beside the vault of the excavation and patches of coarse wax similar to that of the carder-bee. Social-Wasps. The nest of the common wasp ( Vespa vulgaris) attracts more or less the attention of everybody ; but its interior architecture is not so well known as it deserves to be, for its singular ingenuity, in which it rivals even that of the hive-bee (^Ajns 7neUiJica). In their general economy the social or republican wasps closely resemble the humble- bee (^Bombus), every colony benig founded by a single 60 INSECT ARCHITECTURE. female who has survived the winter, to the rigours of which all her summer associates of males and working wasps uniformly fall victims. Nay, out of three hundred females which may be found in one vespiary, or wasp's nest, towards the close of autumn, scarcely ten or a dozen survive till the ensuing spring, at which season they awake from their hybernal lethargy, and begin with ardour the labours of colonization. It may be interesting to follow one of these mother wasps through her several operations, in which she merits more the praise of industr}^ than the queen of a bee-hive, who does nothing, and never moves without a numerous train of obedient retainers, always ready to execute her commands and to do her homage. The mother wasp, on the contrary, is at first alone, and is obliged to perform every species of drudgery herself. Her first care, after being roused to activity by the re- turning warmth of the season, is to discover a place suitable for her intended colony ; and, accordingly, in the spring, wasps may be seen prying into every hole of a hedge-bank, particularly where field-mice have burrowed. Some authors report that she is partial to the forsaken galleries of the mole ; but this does not accord with our observations, as we have never met with a single vespiary in any situation likely to have been frequented by moles. But though we cannot assert the fact, we think it highly probable that the deserted nest of the field-mouse, which is not uncommon in hedge-banks, may be sometimes appropriated by a mother wasp as an excavation convenient for her purpose. Yet, if she does make choice of the burrow of a field-mouse, it requires to be afterwards considerably enlarged in the interior chamber, and the entrance gallery veiy much narrowed. The desire of the wasp to save herself the labour of excavation, by forming her nest where other animals have burrowed, is not without a j)arallel in the actions of quad- rupeds, and even of birds. In the splendid continuation of Wilson's American Ornithology, by Charles L. Bonaparte (whose scientific pursuits have thrown round that name a SOCIAL-WASPS. 61 beneficent lustre, pleasingly contrasted with his uncle's glory), there is an interesting example of this instinctive adoption of the labours of others, " In the trans-Mississip- pian territories of the United States, the burrowing-owl resides exclusively in the villages of the marmot, or prairie- dog, whose excavations are so commodious, as to render it unnecessary that the owl should dig for himself, as he is said to do where no burrowing animals exist.* The villages of the prairie-dog are very numerous and variable in their extent, — sometimes covering only a few acres, and at others spreading over the surface of the country for miles together. They are composed of slightly-elevated mounds, having the form of a truncated cone, about two feet in width at the base, and seldom rising as high as eighteen inches from the surface of the soil. The entrance is placed either at the top or on the side, and the whole mound is beaten down externally, especially at the summit, resembling a much- used footpath. From the entrance, the passage into the mound descends vertically for one or two feet, and is thence continued obliquely downwards imtil it terminates in an apartment, within which the industrious prairie-dog con- structs, on the approach of cold weather, a comfortable cell for his winter's sleep. The cell, which is composed of fine dry grass, is globular in form, with an opening at top, capable of admitting the finger ; and the whole is so firmly compacted, that it might without injury, be rolled over the floor."t In case of need the wasp is abundantly furnished by nature with instruments for excavating a burrow out of the solid ground, as she no doubt most commonly does, — digging the earth with her strong mandibles, and carrying it off or pushing it out as slie proceeds. The entrance- gallery is about an inch or less in diameter, and usually runs in a winding or zigzag direction, from one to two feet in depth. In the chamber to which this gallery leads, and * The owl observed by Vieillot in St. Domingo digs itself a burrow two feet in depth, at the bottom of which it deposits its eggs upon a bed of moss. t American Ornitholog}% by Charles Lucien Bonaparte, vol. i. p. 69, 62 IXSECT ARCHITECTURE. wliicL, when completed, is from one to two feet in diameter, the mother wasp lays the foundations of her city, beginning with the walls. The building materials emploj^ed by wasps Avere long a matter of conjecture to scientific inquirers; for the bluish- gi'ey papery substance of the whole structure has no resem- blance to any sort of wax employed by bees for a similar purpose. Now that the discovery has been made, we can with difficult}^ bring ourselves to believe that a naturalist so acute and indeftitigible as M. Eeaumur, should have, for twenty years, as he tells us, endeavoured, without success, to find out the secret. At length, however, his perseverance was rewarded. He remarked a female wasp alight on the sash of his window, and begin to gnaw the wood with her mandibles ; and it struck him at once that she was procur- ing materials for building. He saw her detach from the wood a bundle of fibres about a tenth of an inch in length, and finer than a hair ; and as she did not swallow these, but gathered them into a mass with her feet, he could not doubt that his first idea was correct. In a short time she shifted to another pail of the window-frame, carrying with her the fibres she had collected, and to which she continued to add, when he caught her, in order to examine the nature of her bundle ; and he found that it was not 3'et moistened nor rolled into a ball, as is always done before emploj^ing it in building. In every other respect it had precisely the same colour and fibrous texture as the walls of a vespiary. It struck him as remai'kable that it bore no resemblance to wood gnawed by other insects, such as the goat-moth cater- pillar, which is granular like sawdust. This would not have suited the design of the wasp, who was well aware that fibres of some length form a stronger texture. He even discovered, that before detaching the fibres, she bruised them Qes charpissoit) into a sort of lint (charine) with her mandibles. All this the careful naturalist imitated by bruising and paring the same wood of the window-sash with his penknife, till he succeeded in making a little bundle of fibres scarcely to be distinguished from that collected by the wasp. SOCIAL-WASPS. 63 We have ourselves frequently seen wasps employed in procuring their materials in this manner, and have always observed that they shift from one part to another more than once in preparing a single load, — a circumstance which we ascribe entirely to the restless temper peculiar to the whole order of hymenopterous insects. Eeaumur found that the wood which they preferred was such as had been long ex- posed to the weather, and is old and dry. White of Sel- borne, and Kirby and Spence, on the contrary, maintain tliat wasps obtain their paper from sound timber, hornets only from that which is decayed.* Our own observations, however, confirm the statement of Eeaumur with respect to wasps, as, in every instance which has fallen under our notice, the wood selected was very much we.athered : and in one case an old oak post in a garden at Lee, in Kent, half destroyed by dry-rot, was seemingly the resort of all the wasps in the vicinity. In another case, the deal bond in a brick wall, which had been built thirty years, is at this moment TJune, 1829) literally striped with the gnawings of wasps, which we have watched at the work for hours together. (J. E.) The bundles of ligneous fibres thus detached, are mois- tened before being used, with a glutinous liquid, which causes them to adhere together, and are then kneaded into a sort of paste, or papier mache. Having prepared some of this material, the mother wasp begins first to line with it the roof of her chamber, for wasps always build downwards. The round ball of fibres which she has previously kneaded up with glue, she now forms into a leaf, walking back- wards, and spreading it out with her mandibles, her tongue, and her feet, till it is as thin almost as tissue paper. One sheet, however, of such paper as this would form but a fragile ceiling, quite insufficient to prevent the earth from falling down into the nest. The wasp, accordingly, is not satisfied with her work till she has spread fifteen or sixteen layei*s one above the other, rendering the wall alto- gether nearly two inches thick. The several layers are not * Reaumur, vol. vi. bottom of pa,2:e 182 ; Hist, of Sell), ii. 228 ; and lutrod. to Eutomol. i. 504, 5th edition. 64 IXSECT ARCHITECTURE. placed in contact like the layers of a piece of pasteboard, but with small intei-^^als or open spaces between, appear- ing somewhat like a grotto built with bivalve shells, particularly when looked at on the outside. This is pro- bably caused b}^ the insect working in a curvilineal manner. Having finished the ceiling, she next begins to build the first terrace of her city, which, under its protection, she suspends horizontally, and not, like the combs in a bee-hive, in a pei-pendicular position. The suspension of which we speak is also light and elegant, compared with the more Section of the Social- Wasp's Xest. a a, the external wall; b, c c, five small terraces of cells for the neuter wasps; d d, e e, three rows of larger cells for the males and females. heavj^ union of the hive-bees' combs. It is, in fact, a hang- ing floor, immoveably secured by rods of similar materials with the roof, but rather stronger. From twelve to thirty of these rods, about an inch or less in length, and a quarter of an inch in diameter, are constructed for the suspension of the terrace. They are elegant in form, being made SOCIAL-WASrS. 65 gradually narrower towards the middle, and widening at each end, in order, no doubt, to render their hold the stronger. The terrace itself is circular, and composed of an immense number of cells, formed of the paper already described, and of almost the same size and form as those of a honeycomb, each being a perfect hexagon, mathematically exact, and every hair's breadth of the space completely filled. These cells, however, are not used as honey-pots by wasps, as they are by bees ; for wasps, certain foreign species excepted, make no honey, and the cells are wholly appropriated to the rearing of their young. Like other hymenopterous insects, the grubs are placed with their heads downwards ; and the openings of the cells are also downwards; while their united bottoms form a nearly uniform level upon which the inhabitants of the nest may walk. We have seen, in describing the economy of the carder-bee, that when a young bee had escaped from its cradle-cell, and so rendered it empty, that cell was subsequently appropriated to the storing of honey. But in the case of wasps, a cell thus evacuated is immediately cleaned out and repaired for the reception of another grub — an egg being laid in it by a female wasp as soon as it is ready. When the foundress-wasp has completed a certain number of cells, and deposited eggs in them, she soon intermits her building operations, in order to procure food for the young grubs, which now require all her care. . In a few weeks these become perfect wasps, and lend their assistance in the extension of the edifice ; enlarging the original coping of the foundress by side walls, and forming another platform of cells, suspended to the first by columns, as that had been suspended to the ceiling. In this manner several platforms of combs are constructed, the outer walls being extended at the same time ; and, by the end of the summer, there is generally from twelve to fifteen platforms of cells. Each contains about 1000 cells — forty-nine being contained in an inch and a half square, and, of course, making the enormous number of about 16,000 cells in one colony. Reaumur, upon these data, F 66 INSECT ARCHITECTURE. calculates that one vespiary may produce every year more than 30,000 wasps, reckoning only 10,000 cells, and each serving successively for the cradle of three generations- But, although the whole structure is built at the expense of so much labour and ingenuity, it has scarcely been finished before the winter sets in, when it becomes nearly useless, and serves only for the abode of a few benumbed females, who abandon it on the approach of spring, and never A, represents one of the rods from which the terraces are suspended. B, a portion of the external crust. return ; for wasps do not, like mason-bees, ever make use of the same nest for more than one season. Both Eeaumur and the younger Huber studied the proceedings of the common wasp in the manner which has been so successful in observing bees — by means of glazed hives, and other contrivances. In this, these na- turalists were greatly aided by the extreme affection of wasps for their young ; for though their nest is carried off, or even cut in various directions, and exposed to the light, they never desert it, nor relax their attention to their progeny. When a wasp's nest is removed from its natural situation, and covered with a glass hive, the first operation of the inhabitants is to i^epair the injuries it has suffered. They carry off with surprising activity all the earth or other matters which have fallen by accident into the nest; and when they have got it thoroughly cleared of everything extraneous, they begin to secure it from further derangement, by fixing it to the glass with papyraceous columns, similar to those which we have already described. The breaches which the nest may have suffered are then repaired, and the thickness of the walls is SOCIAL-WASPS. iji augmented, with the design, perhaps, of more effectually excluding the light. The nest of the hornet is nearly the same in structure with that of the wasp ; but the materials are considerably coarser, and the columns to which the platforms of cells are suspended are larger and stronger, the middle one being twice as thick as any of the others. The hornet, also, does not build underground, but in the cavities of trees, or in the thatch or under the eaves of barns. Eeaumur once found upon a wall a hornet's nest which Hornet's Nest in its first stage. had not been long begun, and had it transferred to the outside of his study-window ; but in consequence, as he imagined, of the absence of the foundress-hornet at the time it was removed, he could not get the other five hornets, of which the colony consisted, either to add to the building or repair the damages which it had sustained. M. Reaumur differs from our English naturalists, A\hite, 68 INSECT ARCHITECTURE. and Kirby and Silence, with, respect to tlie materials em- ployed by the hornet for building. The latter say that it employs decayed wood ; the former, that it uses the bark of the ash-tree, but takes less pains to split it into fine fibres than wasps do ; not, however, because it is destitute of skill ; for in constructing the suspensory columns of the platforms, a paste is prepared little inferior to that made by wasps. We cannot, from our own observations, decide which of the above statements is correct, as we have only once seen a hornet procuring materials, at Compton-Bassett, in Wiltshire ; and in that case it gnawed the inner bark of an elm which had been felled for several months, and was, consequently, dry and tough. Such materials as this would account for the common yellowish-brown colour of a hornet's nest. (J..E.) When hornets make choice of a tree for their domicile, they select one which is in a state of decay, and already partly hollowed; but they possess the means, in their sharp and strong mandibles, of extending the excavation to suit their purposes ; and Eeaumur frequently witnessed their operations in mining into a decayed t]-ee, and carrying off what they had gnawed. He observed, also, that in such cases they did not make use of the large hole of the tree for an entrance, but went to the trouble of digging a gallery, sufScient for the passage of the largest hornet in the nest, th-rough the living and undecayed portion of th.e tree. As this is perforated in a winding direction, it is no doubt intended for the purpose of protecting the nest from the intrusion of depredators, who could more easily eifect an entrance if there were not such a tortuous way to pass through. One of the most remarkable of our native social-wasps is the ti^ee-wasp ( Vesjm Britannica), which is not uncommon in the northern, but is seldom to be met with in the southern parts of the island. Instead of burrowing in the ground like the common wasp ( Vespa vulgaris), or in the hollows of trees like the hornet ( Vespa crahro), it boldly swings its nest from the extremity of a branch, where it SOCIAL-WASPS. 69 exhibits some resemblance, in size and colour, to a Welsli wig hung out to dry. We have seen more than one of these nests on the same tree, at Catrine, in Ayrshire, and at A¥emyss Bay, in Renfrewshire. The tree which the Britannic wasp prefers is the silver fir, whose broad flat branch serves as a protection to the suspended nest both from the sun and the rain. AYe have also known a wasp's nest of this kind in a gooseberry-bush, at Eed-house Castle, East Lothian. The materials and structure are nearly the same as those employed by the common wasp, and which we have already described. (J. E.) A singular nest of a species of wasp is figured by Eeaumur, but is apparently rare in this country, as Kirby and Spence mention only a single nest of similar construc- tion, found in a garden at East-Dale. This nest is of a flattened globular figure, and composed of a great number of envelopes, so as to assume a considerable resemblance to a half-expanded Provence rose. The British specimen mentioned by Kirby and Spence had only one platform of cells ; Eeaumur had two ; but there was a large vacant space, which would probai3ly have been filled with cells, had the nest not been taken away as a specimen. The whole nest was not much larger than a rose, and was com- posed of paper exactly similar to that employed by the common ground- wasp.* * Two British species of wasp, Vespa Holsatica, Fabr., and Vespa Britannica, Leach, if indeed they be truly distinct species, make pendent vespiaries, attached to the branch of a shrub or tree. The nest of the Vespa Holsatica is said to be much larger than that of the other, and in the north of England it is often found in gooseberry-bushes. A nest of this kind we have ourselves seen in such a bush, in Derbyshire, — it was pendent and loosely constructed externally of foliaceous layers. In the Mag. of Nat. Hist. 1839, p. 458, Mr. Shuckard gives an account of the nest of a wasji, which he regards as Vespa Britannica, — remarkable for the material of which it was constructed, and for the locality in which it was found. This nest, which was exhibited at a meeting of the Entomological Society, was foiuid near Croydon, built in a sparroAv's nest, and attached to the lining feathers. " The smallness of the nest," says Mr. Shuckard, " and also of the tier of cells, as well as the peculiar material of which it appeared composed, led to a discussion, the tendency of which seemed to support the opinion that it was most probably the 70 IXSECT ARCHITECTURE. There is another species of social-wasp {Epipone nidulans, Latr.) meriting attention from the singular construction of its nest. It forms one or more terraces of cells, similar to those of the common wasp, but without the protection of an outer wall, and quite exposed to the weather. Swam- W'asp's Xest. merdam found a nest of this description attached to the stem of a nettle. Reaumur says they are sometimes attached to the branch of a thorn or other shrub, or to stalks of grass ;— peculiarities which prove that there are several species of these wasps. neat of a Polistcs, a social-wasp not yet found in this coimtry, but if not of Polistes, certainly not yet determined or known." The nest was ovate, about an inch and a half long, with a tier of cells internally, originating from a common pedicle. It aj^peared to be constnicted " of the agglutinated particles of a soft white wood, probably willow, very imperfectly tritrmited ;" whence it had externally a rough granulated appearance. It Avas sprinkled with black specks, arising perhaps from the intermixtiu-e of more decayed portions of the wood ; and was of a very fragile textiu-e. " The natiu-e of the material, and its unfinished execution, as well as tlie situation in which it was found, appear to me to be its own peculiarities, and I nuist necessarily consider it merely an accidental variation in material and locality from the usual nests of the Vespa Britannica of Leach." — ]Mr. Shuckard concludes his paper by stating that he strongly suspects the identity of Vespa Holsatica and Vespa Britannica. SOCIAL-WASPS. 71 The most remarkable circumstance in the architecture of this species of vespiary is, that it is not horizontal, like those formerly described, but nearly vertical. The rea- son appears to be, that if it had been horizontal, the cells must have been frequently filled with rain ; whereas, in the position in which it is placed, tlie rain runs off with- out lodging. It is, besides, invariably placed so as to face the north or the east, and consequently is less exposed to rains, which most frequently come with southerly or westerly winds. It is another remarkable peculiarity, that, unlike the nests of other wasps, it is covered with a shining coat of varnish, to prevent moisture from soaking into the texture of the wasp's paper. The laying on this varnish. Wasps' Cells attached to a Branch. indeed, forms a considerable portion of the labour of the colony, and individuals may be seen employed for hours together spreading it on with their tongues. Few circumstances are more striking, with regard to insects, as Kirby and Spence justly remark, than the great and incessant labour which maternal affection for their progeny leads them to undergo. Some of these 72 INSECT ARCHITECTURE. exertions are so disproportionate to the size of the insect, that nothing short of ocular conviction cotild attribute them to such an agent. A wild bee, or a wasp, for instance, as we have seen, will dig a hole in a hard bank of earth some inches deep, and five or six times its own size, labouring unremittingly at this arduous task for several days in succession, and scarcely allowing itself a moment for eating or repose. It will then occupy as much time in searching for a store of food ; and no sooner is this finished, than it will set about repeating the process, and, before it dies, will have completed five or six similar cells, or even more. We shall have occasion more particularly to dwell upon the geometrical arrangement of the cells, both of the wasp and of the social-bee, in our description of those interesting operations, which have long attracted the notice, and com- manded the admiration of mathematicians and naturalists. A few observations may here be properly bestowed upon the material with which the wasp-family construct the interior of their nests. The wasp is a paper-maker, and a most perfect and intelligent one. AVhile mankind were arriving, by slow degrees, at the art of fabricating this valuable substance, the wasp was making it before their eyes, by very much the same process as that by which human hands now manufacture it with the best aid of chemistry and ma- chinery. While some nations carved their records on wood, and stone, and brass, and leaden tablets, — others, more advanced, wrote with a style on wax, — others em- ployed the inner bark of trees, and others the skins of animals rudely prepared, — the wasp was manufacturing a firm and durable paper. Even when the papyrus was rendered more fit, by a process of art, for the transmission of ideas in writing, the wasp was a better artisan than the Egyptians ; for the early attempts at paper- making were so rude, that the substance produced was almost useless, from being extremely friable. The paper of the papyrus was formed of the leaves of the plant, dried, pressed, and polished ; the wasp alone knew how to reduce vegetable SOCIAL-WASPS. 73 fibres to a pulp, and then unite tliem by a size or glue, spreading the substance out into a smooth and delicate leaf. This is exactly the process of paper-making. It would seem that the wasp knows, as the modern paper- makers now know, that the fibres of rags, whether linen or cotton, are not the only materials that can be used in the formation of paper ; she employs other vegetable matters, converting them into a proper consistency by her assiduous exertions. In some respects she is more skilful even than our paper-makers, for she takes care to retain her fibres of sufficient length, by which she renders her paper as strong as she requires. Many manufacturers of the present day cut their material into small bits, and thus produce a rotten article. One great distinction between good and bad paper is its toughness ; and this difference is invariably produced by the fibre of which it is composed being long, and there- fore tough ; or short, and therefore friable. The wasp has been labouring at her manufacture of paper, from her first creation, with precisely the same instruments and the same materials ; and her success has been unvarying. Her machinery is very simple, and there- fore it is never out of order. She learns nothing, and she forgets nothing. Men, from time to time, lose their excel- lence in particular arts, and they are slow in finding out real improvements. Such improvements are often the effect of accident. Paper is now manufactured very extensively by machinery in all its stages ; and thus, instead of a single sheet being made by hand, a stream of paper is poured out, which would form a roll large enough to extend round the globe, if such a length were desirable. The inventors of this machinery, Messrs. Fourdrinier, it is said, spent the enormous sum of 40,000/. in vain attempts to render the machine capable of determining with precision the width of the roll ; and, at last, accomplished their object, at the suggestion of a bystander, by a strap revolving upon an axis, at a cost of three shillings and sixpence. Such is the difference between the workings of human knowledge and experience, and those of animal instinct. We proceed slowly and in the dark — but our course is not bounded by 74 IXSECT ARCHITECTURE. a narrow line, for it seems difficult to say what is tlie perfection of any art ; animals go clearly to a given point — but tliey can go no further. We may, however, learn something from their perfect knowledge of what is within their range. It is not improbable that if man had attended in an earlier state of society to the labours of wasps, he w^oiild have sooner known how to make paper. \\e are still behind in our arts and sciences, because we have not always been observers. If we had watched the operations of insects, and the stnicture of insects in general, with more care, we might have been far advanced in the know- ledge of many arts which are yet in their infancy, for nature has given us abundance of patterns. We have learnt to perfect some instruments of sound by examining the structure of the human ear ; and the mechanism of an e^^e has suggested some valuable improvements in achro- matic glasses. Eeaumur has given a very interesting account of the wasps of Cayenne (Chartergus nidulans), which hang their nests in trees.* Like the bird of Africa called the social grosbeak (Loxia socio), they fabricate a perfect house, capable of containing many hundreds of their communit}^ and suspend it on high out of the reach of attack. But the Cayenne wasp is a more expert artist than the bird. He is a pasteboard-maker ; — and the card with which he forms the exterior covering of his abode is so smooth, so strong, so imiform in its texture, and so white, that the most skilful manufacturer of this substance might be proud of the work. It takes ink admirably. The nest of the pasteboard-making wasp is impervious to water. It hangs upon the branch of a tree, as represented in the engraving; and those rain-drops which penetrate through the leaves never rest upon its hard and polished surface. A small opening for the entrance of the insects terminates its funnel-shaped bottom. It is impossible to unite more perfectly" the qualities of lightness and strength. * IMemoires siir les Insectes, torn, vi., mem. vii. See also Bonnet, vol. ix. SOCIAL-WASPS. 75 In the specimen from which we take our description, the length of which is nine inches, six stout circular plat- forms stretch internally across, like so many floors, and fixed all round to the walls of the nest. They are smooth above, with hexagonal cells on the under surface. These platforms are not quite flat, but rather concave above, like a watch-glass reversed ; the centre of each platform is perforated for the admission of the wasps, at the extremity of a short funnel-like projection, and through this access is gained from story to story. On each platform, therefore. JS'est of the Pasteboard-maker AVasp, with part removed to show tlie arrangement ol the Cells. can the wasps walk leisurely about attending to the pupa3 secured in the cells, which, with the mouths downward, cover the ceiling above their heads — the height of the latter being just convenient for their work. Pendent wasps'-nests of enormous size are found in Ceylon, 76 INSECT ARCHITECTURE. suspended often in the talipot-tree at the height of seventy feet. The appearance of these nests thus elevated, with the larger leaves of the tree, used by the natives as umbrellas and tents, waving over them, is very singular. Though no species of European wasp is a storer of honey, yet this rule does not apply to certain species of South America. In the * Annals and Magazine of Natural History' for June, 1841, will be found a detailed account, with a figure, of the pendent nest of a species termed by Mr. A. White Myraptera sGutellaris. The external case consists of stout cardboard covered with conical knobs of various sizes. The entrances are artfully protected by pent-roofs from the weather and heavy rains ; and are toi-tuous, so as to render the ingress of a moth or other large insect difficult. Internally are fourteen combs, exclusive of a globular mass, the nucleus of several circular combs, which are succeeded by others of an arched form — that is, constituting segments of circles. Many of the uppermost combs were found to have the cells filled with honey of a brownish-red colour, but which had lost its flavour. After entering into some minute details, Mr. A. AVhite makes the following interesting observations : — " Azara, in the account of his residence in various parts of South America, mentions the fact of several icasps of these countries collecting honey. The Baron Wachenaer, who edited the French translation of this work, published in 1809, thought that the Spanish traveller, who was unskilled in entomology, had made some mistake with regard to the insects, and regarded the so-called wasps as belonging to some hee of the genus of which Apis amaltliea is the type (MeUpona). Latreille (who afterwards corrected his mistake) also believed that they must be referred to the genera MeUpona or Trigona — insects which in South America take the place of our honey-bee. These authors were afterwards clearly convinced of the correctness of Azara's observations, by the circumstance of M. Auguste de St. Hilaire finding near the river Uruguay an oval grey-coloured nest of a papery consistence, like that of the European wasps, suspended from the branches of a small shrub about a foot from the ground: he and two other attendants partook of SOCIAL-WASPS. 77 some honey (contained in its cells) and found it of an agreeable sweetness, free from the pharmaceutic taste which so frequently accompanies European honey. He gives a detailed account of its poisonous effects on himself and his two men." Afterwards he procured specimens of the wasp, which was described by Latreille under the name of Polistes Lecheguana. It would seem that, the nest described by Mr. White agrees with that of a wasp termed Cliiguana by Azara (or Lecheguana), and is very different to the slight paperj" nest of the Polistes Lecheguana of Latreille. We may add that M. Auguste de St. Hilaire speaks of two species of wasp remarkable for storing honey in South America ; the honey of one is white, of the other reddish. That the habits of these honey-wasps must differ considerably from those of any of our European species we may at once admit ; perhaps in some points of their economy these insects may approach the bee. ( '8 ) CHAPTEE V. ARCHITECTURE OF THE BEE-HIVE. ^9 m't^H |f ill- ffm i„ ".fA? Part of a Honeycomb, and Bees at work. Although the liive-bee {Apis mellifica) has engaged the attention of the curious from the earliest ages, recent dis- coveries prove that we are yet only beginning to arrive at a correct knowledge of its wonderful proceedings. Pliny informs us that Astromachus, of Soles, in Cilicia, devoted fifty-eight years to the study ; and that Philiscus the Thracian spent his whole life in forests for the purpose of observ'ing them. But in consequence (as we may naturally infer) of the imperfect methods of research, assuming that what they did discover was known to Aristotle, Columella, and Pliny, we are justified in pronouncing the statements of these philosophers, as well as the embellished poetical pictures of Virgil, to be nothing more than conjecture, almost in every particular erroneous. It was not indeed HIVE-BEES. 79 till 1712, when glass hives were invented by Maraldi, a mathematician of Nice, that what we may call the in-door proceedings of bees could be observed. This important invention was soon afterwai'ds taken advantage of by M. Eeanmnr, who laid the foundation of the more recent discoveries of John Hunter, Schirach, and the Hubers. The admirable architecture which bees exhibit in their miniature cities has, by these and other naturalists, been investigated with great care and accuracy. We shall endeavour to give as full an account of the wonderful structures as our limits will allow. In this we shall chiefly follow M. Huber, the elder, whose researches appear almost miraculous when we consider that he was blind. At the early age of seventeen this remarkable man lost his sight by gutta serena, the " drop serene " of our own Milton. But though cut off from the sight of Nature's works, he dedicated himself to their study. He saw them through the eyes of the admirable woman whom he married ; his philosophical reasonings pointed out to her all that he wanted to ascertain ; and as she reported to him from time to time the results of his ingenious experiments, he was enabled to complete, by diligent investigation, one of the most accurate and satisfactory accounts of the habits of bees which have ever been produced. It had long been known that the bees of a hive consist of three sorts, which was ascertained by M. Eeaumur to be distinguished as workers or neuters, constituting the bulk of the population ; drones or males, the least numerous class ; and a single female, the queen and mother of the colony. Schirach subsequently discovered the very extraordinary fact, which Huber and others have proved beyond doubt, that when a hive is accidentally deprived of a queen, the grub of a worker can be and is fed in a particular manner so as to became a queen and supply the loss.* But another discovery of M. Huber is of more importance to the subject * It is right to remark that Huish aud others have suggested that tlie grubs thus royalized may originally be misplaced queens ; yet this admission is not necessary, since Madlle. Jmine has proved, by dissec- tion, the workers to be imperfect females. 80 INSECT ARCHITECTURE. of architecture now before iis. By minute research, he ascertained that the workers which had been considered by former naturalists to be all alike, are divided into two important classes, nurse-bees and wax-makers. The nurse-bees are rather smaller than the wax-workers, and even when gorged with honey their belly does not, as in the others, appear distended. Their business is to collect honey, and impart it to their com23anions ; to feed and take care of the young grubs, and to complete the combs and cells which have been founded by the others ; but they are not charged with provisioning the hive. The wax-workers, on the other hand, are not only a little larger, but their stomach, when gorged with honey, is capable of considerable distention, as M. Huber jDroved by repeated experiments. He also ascertained that neither of the species can alone fulfil all the functions shared among the workers of a hive. He painted those of each class with different colours, in order to study their proceedings, and their labours were not interchanged. In another experi- ment, after supplying a hive deprived of a queen with.brood and pollen, he saw the nurse-bees quickly occupied in the nutrition of the grubs, while those of the wax-working class neglected them. When hives are full of combs, the wax- workers disgorge their honey into the ordinary magazines, making no wax : but if they want a reservoir for its recep- tion, and if their queen does not find cells ready made wherein to lay her eggs, they retain the honey in the stomachj and in twenty-four hours they produce wax. Then the labour of constructing combs begins. It might perhaps be supposed that, when the country does not afford honey, the wax-workers consume the provi- sion stored up in the hive. But they are not permitted to touch it. A portion of honey is carefully preserved, and the cells containing it are protected by a waxen covering, which is never removed except in case of extreme necessity, and when honey is not to be otherwise procured. The cells are at no time opened during summer ; other reservoirs, always exposed, contribute to the daily use of the com- munity; each bee, however, supplying itself from them HIVP>13EES. 81 with nothing but what is required for present wants. Wax- workers appear with large bellies at the entrance of their hive, only when the country affords a copious collection of honey. From this it may be concluded that the production of the waxy matter depends on a concurrence of circum- stances not invariably' subsisting. Nurse-bees also produce wax, but in a very inferior quantity to what is elaborated by the real wax-workers. Another characteiistic whereby an attentive observer can determine the moment of bees collecting sufficient honey to produce wax, is the strong odour of both these substances from the hive, which is not equally intense at any other time. From such data, it was easy for M. Huber to discover whether the bees worked in wax in his own hives, and in those of the other cultivators of the district. There is still another sort of bees, first observed by Huber in 1809, which appear to be only casual inmates of the hive, and which are driven forth to starve, or are killed in conflict. They closely resemble the ordinary workers, but are less hairy, and of a much darker colour. These have been' called hlack bees, and are supposed by Huber to be defective bees;* but Kirby and Spence conjecture that they are toil-worn superannuated workers, of no further use, and are therefore sacrificed, because burden- some to a community which tolerates no unnecessary inmates. The very great number of black bees, however, which sometimes appear, does not well accord with such an opinion. The subject remains, therefore, still in uncer- tainty. Preparation of Wax. In order to build the beautiful combs, which every one must have repeatedly seen and admired, it is indispensable that the architect-bees should be provided with the materials — with the wax, in short, of which they are principally formed. Before we follow them, therefore, to the operation of building, it maybe necessary to inquire how the wax itself is procured. Here the discoveries of recent inquirers have * Huber on Bees, p. 338. 82 INSECT ARCHITECTURE. been little less singular and unexpected tlian in other departments of the history of these extraordinary insects. Now that it has been proved that wax is secreted by bees, it is not a little amusing to read the accounts given by our elder naturalists, of its being collected from flowers. Our countr^'man, Thorley,* appears to have been the first who suspected the true origin of wax, and Wildman (17(39) seems also to have been aware of it; but Eeaumur, and particularly Bonnet, though both of them in general shrewd and accurate observers, were partially deceived by appearances. The bees, we are erroneously tokl, search for wax "upon all sorts of trees and plants, but es]iecially the rocket, the simple poppy, and in general all kinds of flowers. They amass it with their hair, with which their whole body is invested. It is something pleasant to see them roll in the yellow dust which falls from the chives to the bottom of the flowers, and then return covered with the same grains ; but their best method of gathering the wax, especially when it is not very plentiful, is to carry away all the little particles of it with their jaws and fore feet, to press the wax upon them into little pellets, and slide them one at a time, with their middle feet, into a socket or cavity, that opens at their hinder feet, and serves to keep the burthen fixed and steady till they retuin home. They are sometimes exposed to inconveniences in this work by the motion of the air, and the delicate texture of the flowers which bend under their feet, and hinder them from packing up their booty, on which occasions they fix themselves in some steady place, where they press the wax into a mass, and wind it roinid their legs, making fi*equent returns to the flowers ; and when they have stocjked themselves with a suflicient quan- tity, they immediately repair to their habitation. Two men, in the compass of a whole day, could not amass so much as two little balls of wax ; and yet they are no more than the common burthen of a single bee, and the produce of one journey. Those who are employed in collecting the wax from flowers are assisted by their companions, who * Melisselogia, or Female Monarchy, Svo., Lond. IT-Ii. ( HIVE-BEES. 83 attend them at tlie door of the hive, ease them of their load at their arrival, brush Iheir feet, and shake out the two balls of wax ; upon which the others return to the fields to gather new treasure, while those who disburthened them convey their charge to the magazine. But some bees, again, when they have brought their load home, cany it themselves to the lodge, and there deliver it, laying hold of one end by their hinder feet, and with their middle feet sliding it out of the cavity that contamed it ; but this is evidently a work of supererogation which they are not obliged to perform. The packets of wax continue a few moments in the lodge, till a set of officers come, who are charged w^tli a third commission, which is to knead this wax with their feet, and spread it out into diiferent sheets, laid one above another. This is the unwrought wax, which is easily distinguished to be the produce of different flowers, by the variety of colours that appear on each sheet. When they afterwards come to work, they knead it over again ; they purify and whiten, and then reduce it to a uniform colour. They use this wax with a wonderful frugality ; for it is easy to observe that the whole family is conducted by prudence, and all their actions regulated by good govern- ment. Everything is granted to necessity, but nothing to superfluity ; not the least grain of wax is neglected, and if they waste it, they are frequently obliged to provide more ; at those very times when they want to get their provision of honey, they take off the wax that closed the cells, and carry it to the magazine."* Reaumur hesitated in believing that this was a correct view of the subject, from observing the great diflerence between wax and pollen ; but he was inclined to think the pollen might be swallowed, partially digested, and disgorged in the form of a kind of paste. Schirach also mentions, that it was remarked by a certain Lusatian, that wax comes from the rings of the body, because, on withdrawing a bee while it is at work, and extending its body, the wax may be seen there in the form of scales. The celebrated John Hunter shrewdly remarked that the * De la Pluche, Spectacle de la Natm-e, vol. i. 84 INSECT ARCHITECTURE. pellets of pollen seen on the thighs of bees are of different colours on different bees, while the shade of the new-made comb is always uniform ; and' therefore he concluded that pollen was not the origin of wax. Pollen also, he observed, is collected with greater avidity for old hives, where the comb is complete, than for those where it is only begun, which would hardly be the case were it the material of wax. He found that when the weather was cold and wet in June, so that a young swarm was prevented from going abroad, as much comb was constructed as had been made in an equal time when the weather was favourable and fine. The pellets of pollen on the thighs being thence proved not to be wax, he came to the conclusion that it was an external secretion, originating between the plates of the belly. When he first observed this, he felt not a little embarrassed to explain the phenomenon, and doubted whether new plates were forming, or whether bees cast their old ones as lobsters do their shell. By melting the scales, he ascertained at least that they were wax ; and his opinion was confirmed by the fact, that the scales are only to be found during the season when the combs are con- structed. But he did not succeed in completing the dis- covery by observing the bees actually deta(?h the scales, though he conjectured they might be taken up by others, if they were once shaken out from between the rings.* • We need not be so much surprised at mistakes committed upon this subject, when we recollect that honey itself was believed by the ancients to be an emanation of the air- — a dew that descended uj)on flowers, as if it had a limited commission to fall only on them. The exposure and cor- rection of error is one of the first steps to genuine know- ledge ; and when we are aware of the stumbling-blocks whicli have interrupted the progress of others, avc can always travel more securely in the wa}^ of truth. That wax is secreted is proved both by the wax-pouches within the yings of the abdomen, and by actual experiment. Huber and others fed bees entirely upon honey or sugar, * Philosopliical Trans, for 1792, p. 143. HIVE-BEES. 85 and, notwitlistanding, wax was produced and combs formed "as if they had been at liberty to select their food, " ^\"hen bees were confined," says M. Hnber, " for the purpose of discovering Avhether honey w^as sufficient for the production of wax, they supported their captivity patiently, and showed uncommon perseverance in rebuilding their combs as we lemoved them. Our experiments required the presence of grubs ; honey and water had to be provided ; the bees were to be supplied with combs containing brood, and at tJie same time it was necessary to confine them, that they might not seek pollen abroad. Having a swarm by chance, which had become useless from sterility of the queen, we devoted it for our investigation in one of my leaf-hives, which Avas glazed on both sides. We removed the queen, and substituted combs containing eggs and young grubs, but no cell with farina ; even the smallest particle of the substance which John Hunter conjectured to be the basis of the nutriment of the young was taken away. " Xothing remarkable occurred during the first and second day : the bees brooded over the young, and seemed to take an interest in them ; but at sunset, on the third, a loud noise was heard in the hive. Impatient to discover the reason, we opened a shutter, and saw all in confusion ; the brood was abandoned, the workers ran in disorder over the combs, thousands rushed towards the lower part of the hive, and those about the entrance gnawed at its grating. Their design was not equivocal ; they wished to quit their prison. Some imperious necessity evidently obliged them to seek elsewhere what they could not find in the hive and apprehensive that they might perish if I restrained them longer from yielding to their instinct, I set them at liberty. The whole swarm escaped, but the hour being unfavourable for their collections, they flew around the hive, and did not depart far from it. Increasing darkness and the coolness of the air compelled them very soon to return. Probably these circumstances calmed their agita- tion ; for we observed them peaceably remounting their combs ; order seemed re-established, and we took advantage of this moment to close the hive. 86 INSECT ARCHITECTURE. "Next day, the lOtli of July, we saw the rudiments of two royal cells, which the bees had formed on one of the brood-combs. This evening, at the same honr as on the preceding, we again heard a loud buzzing in the closed hive; agitation and disorder rose to the highest degree, and we were again obliged to let the swarm escape. The bees did not remain long absent from their habitation ; they quieted and returned as before, ^\e remarked on the 20th that the ro3^al cells had not been continued, as would have been the case in the ordinary state of things. A great tumult took place in the evening ; the bees appeared to be in a delirium ; we set them at liberty, and order was restored on their return. Their captivity having endured five days, we thought it needless to protract it farther ; besides, we were desirous of knowing whether the brood was in a suitable condition, and if it had made the usual progress ; and we wished also to try to discover what might be the cause of the periodical agitation of the bees. M. Burnens (the assistant of Huber), having exposed the two brood-combs, the royal cells were immediately recog- nised ; but it was obvious that they had not been enlarged. AYhy should they ? Neither eggs, grubs, nor that kind of paste peculiar to the individuals of their species were there ! The other cells were vacant likewise ; no brood, not an atom of paste, was in them. Thus, the worms had died of hunger. Had we precluded the bees from all means of sustenance b}^ removing the farina ? To decide this point, it was necessarj^ to confide other brood to the care of the same insects, now giving them abundance of pollen. They had not been enabled to make any collec- tions while we examined their combs. On this occasion they escaped in an apartment where the windows were shut ; and after substituting young worms for those they had allowed to perish, we returned them to their prison. Next day we remarked that they had resumed courage ; they had consolidated the combs, and remained on the brood. They were then provided with fragments of combs, where other workers had stored up farina ; and to be able to observe what they did with it, we took this substance HIVE-BEES. 87 from some of their cells, and spread it on the board of the hive. The bees soon discovered both the farina in the combs and what we had exposed to them. They crowded to the cells, and also descending to the bottom of the hives, took the pollen grain by grain in their teeth, and conveyed it to their mouths. Those that had eaten it most greedily mounted the combs before the rest, and stopping on the cells of the young worms, inserted their heads, and re- mained there for a certain time. M. Burnens opened one of the divisions of the hive gently, and powdered the woi'kers, for the purpose of recognising them when they should ascend the combs. He observed them during several hours, and by this means ascertained that they took so great a quantity of pollen only to impart it to their 3'oung. Then withdrawing the portions of comb which had been placed by us on the board of the hive, we saw that the pollen had been sensibly diminished in quantity. They were returned to the bees, to augment their provision still further, for the purpose of extending the experiment. The royal, as well as several common, cells were soon closed ; and, on opening the hive, all the worms were found to have prospered. Some still had their food before them ; the cells of others that had spun were shut with a waxen covering. " We witnessed these facts repeatedly, and always with equal interest. They so decisively prove the regard of the bees towards the grubs which they are intrusted with rearing, that we shall not seek for any other explanation of their conduct. Another fact, no less extraordinary, and much mol'e difficult to be accounted for, was exhibited by bees constrained to work in wax, several times successively, from the syrup of sugar. Towards the close of the experi- ment they ceased to feed the young, though in the be- ginning these had received the usual attention. They even frequently dragged them from their cells, and carried them out of the hive."* Mr. Wiston, of Germantown, in the United States, men- tions a fact conclusive on this subject. " I had," says he, * Hubcr on Bees. 8S IXSECT ARCHITECTURE. "a late swarm last summer, which, in consequence of the drought, filled only one box with honey. As it was late in the season, and the food collected* would not enable the bees to subsist for the winter, I shut up the hive, and gave them half-a-pint of honey every day. They immediately set to work, filled the empty cells, and then constructed new cells enough to fill another box, in which they de- posited the remainder of the honey." A more interesting proof is thus related by the same gentleman. "In the summer of 1824, I traced some wild bees, w^hich had been feeding on the flowers in my meadow, to their home in the woods, and which I found in the body of an oak-tree, exactly fifty feet above the ground. Having caused the entrance to the hive to be closed by an expert climber, the limbs were separated in detail, until the trunk alone was left standing. To the upper extremity of this, a tackle-fall was attached so as to connect it with an adjacent tree, and, a saw being applied below, the naked trunk was cut through. AMien the immense weight was lowered nearly to the earth, the ropes broke, and the mass fell with a violent crash. The part of the tree which con- tained the hive, separated b}^ the saw% was conveyed to my garden, and placed in a vertical j^osition. On being re- leased, the bees issued out by thousands, and though alarmed, soon became reconciled to the change of situation. By removing a part of the top of the block the interior of the hive was exposed to view, and the comb itself, nearly six feet in height, was observed to have fallen down two feet below the roof of the cavity. To repair the damage \vas the first object of the labourers : in doing which, a large part of their store of honey was expended, because it was at too late a season to obtain materials from abroad. In the following February these industrious but unfortunate insects issuing in a confused manner from the hive, fell dead in thousands aroimd its entrance, the victims of a poverty created by their efforts to repair the ruins of their habitation."* In another experiment, M. Iluber confined a swarm so * American Quarterly Review for June, 1828, p. 382. HIVE-BEES. 89 that they had access to nothing beside honey, and five times successively removed the combs with the precaution of preventing the escape of the bees from the apartment. On each occasion they produced neWcombs, which puts it beyond dispute that honey is sufficient to effect the secre- tion of wax without the aid of pollen. Instead of supply- ing the bees with hone}^, they were subsequently fed, exclusively, on pollen and fruit; but though they were kept in captivity for 'eight days under a bell-glass, with a comb containing nothing but farina, they neither made wax nor was any secreted under the rings. In another series of experiments, in which bees were fed with different sorts of sugar, it was found that nearly one-sixth of the sugar was converted into wax, dark-coloured sugar yielding more than double the quantity of refined sugar. It may not be out of place to subjoin the few anatomical and physiological facts which have been ascertained by Huber, Madlle. Jurine, and Latreille. The first stomach of the worker-bee, according to Worker-boe, magnified— showing tlie position of the scales of Wax. Latreille,* is appropriated to the reception of honey, but this is never found in the second stomach, which is sur- rounded with muscular rings, and from one end to the other very much resembles a cask covered with hoops. It is within these rings that the wax is produced ; but the * Latreille, Mc'm. Acad, des Sciences, 1821. 90 INSECT ARCHITECTUKE. secreting vessels for this purpose have hitherto escaped the researches of the acvitest naturalists. Huber, however, plausibly enough conjectures that they are contained in the internal lining of the wax-pockets, which consists of a cellular substance reticulated with hexagons. The w^ax- pockets themselves, which are concealed b}^ the over- lapping of the rings, may be seen by pressing the abd(jmen of a worker-bee so as to lengthen it, and separate the rings further from each other. AYhen this lias been done, there may be seen on each of the four intermediate hoops of the belly, and separated by what may be called the keel (carina), two whitish-coloured pouches, of a soft texture, and in the form of a trapezium. AVithin, the little scales or plates of wax are produced from time to time, and are Abdomen of Wax- worker Bee. removed and employed as we shall presently see. We may remark, that it is chiefly the wax-workers which produce the wax; for though the nurse-bees are furnished with wax-pockets, they secrete it only in very small quantities ; while in the queen-bee, and the males or drones, no pockets are discoverable. " All the scales," says Huber, " are not alike in every bee, for a difference is perceptible in consistence, shape, and thickness ; some are so thin and transparent as to HIVE-BEES. 1)1 require a magnifier to be recognised, or we have been able to discover nothing but spicnlee similar to those of water freezing. Neither the spiciilse nor the scales rest imme- diately on the membrane of the pocket, a slight liquid medium is interposed, serving to lubricate the joinings of the rings, or to render the extraction of the scales easier, as otherwise they might adhere too firmly to the sides of the jjockets." M. Huber has seen the scales so large as to project bej^ond the rings, being visible without stretching the segments, and of a whitish yellow, from greater thick- ness lessening their transparency. These shades of difierence in the scales of various bees, their enlarged dimensions, the fluid interposed beneath them, the correspondence between the scale, and the size and form of the pockets, seem to infer the oozing of this substance through the membranes whereon it is moulded. He was confirmed in this opinion by the escape of a transparent fluid on piercing the membrane, whose internal surface seemed to be applied to the soft parts of the belly. This he found coagulated in cooling, when it resembled wax, and again liquefied on exposure to heat. The scales themselves, also, melted and coagulated like wax.* By chemical analysis, however, it appears that the wax of the rings is a more simple substance than that which composes the cells ; for the latter is soluble in ether, and in spirit of turpentine, while the former is insoluble in ether, and but partially soluble in spirit of turpentine. It should seem to follow, that if the substance found lying under the rings l:>e really the elements of wax, it undergoes some subsequent preparation after it is detached ; and that the bees, in short, are capable of impregnating it with matter, imparting to it whiteness and ductility, whereas in its unprepared state it is only fusible. Propolis. Wax is not the only material employed by bees in their architecture. Beside this, they make use of a brown, * Hubcr on Bees, p. 325. 92 IXSECT ARCHITECTURE. odoriferous, resinous substance, called propolis,^ more tena- cious and extensible than wax, and well adapted for cementing and varnisliing. It was strongly suspected by Reaumur that the bees collected the propolis from those trees which are known to produce a similar gummy resin, such as the poplar, the birch, and the willow ; but he was thrown into doubt by not being able to detect the bees in the act of procuring it, and by observing them to collect it where none of those trees, nor any other of the same description, grew. Plis bees also refused to make use of bitumen, and other resinous substances, with which he supplied them, though Mr. Knight, as we shall afterwards see, was more successful, j Long before the time of Eeaumur, however, Mouffet, in his Insectaram Theatrum, quotes Cordus for the opinion that propolis is collected from the buds of trees, such as the poplar and birch ; and Keim says it is collected from the pine and fir.| Huber at length set the question at rest; and his experiments and observations are so interesting, that we shall give them in his own words : — " For many years," says he, " I had fruitlessly endea- voured to find them on tre^s producing an analogous sub- stance, though multitudes had been seen returning laden with it. " In July, some branches of the wild poplar, which had been cut since spring, with very large buds, full of a reddish, viscous, odoriferous matter, were brought to me, and I planted them' in vessels before hives, in the way of the bees going out to forage, so that they could not be insensible of their presence. Within a quarter of an hour, the}^ were visited by a bee, which separating the sheath of a bud with its teeth, drew out threads of the viscous substance and lodged a pellet of it in one of the baskets of its limbs ; from another bud it collected another pellet for the opposite limb, and departed to the hive. A second bee * From two Greek words, irpo ttoXls, meaning before the city, as the substance is principally applied to the projecting parts of the hive. t Phil. Trans, for 1807, p. 242. X Schirach, Hist, des Abeilles, p. 241. HIVE-BEES. 93 took tlie place of the former in a few minutes, following tlie same procedure. Young shoots of poplar, recently cut, did not- seem to attract these insects, as their viscous matter had less consistence than the former. * "Different experiments proved the identity of this substance with the propolis; and now, having only to discover how the bees applied it to use, we peopled a hive, so prepared as to fulfil our views. The bees, building upwards, soon reached the glass above ; but, unable to quit their habitation, on account of rain, they were three weeks without bringing home propolis. Their combs remained perfectly white until the beginning of July, when the state of the atmosphere became more favourable for our observa- tions. Serene, warm weather engaged them to forage, and they returned from the fields laden with a resinous gum, resembling a transparent jelly, and having the colour and lustre of the garnet. It was easily distinguished from the farinaceous pellets then collected by other bees. The workers bearing the propolis ran over the clusters, sus- pended from the roof of the hive, and rested on the rods supporting the combs, or sometimes stopped on the sides of their dw^elling, in expectation of their companions coming to disencumber them of their burthen. We actually saw two or three arrive, and carry the propolis from off the limbs of each with their teeth. The upper part of the hive exhibited the most animated spectacle ; thither a multitude of bees resorted from all quarters, to engage in the pre- dominant occupation of the collection, distribution, and application of the propolis. Some conveyed that of which they had unloaded the purveyors in their teeth, and deposited it in heaps; others hastened, l)efore its harden- ing, to spread it out like a varnish, or formed it into strings, proportioned to the interstices of the sides of the hives to be filled up. Nothing could be more diversified than the operations carried on. " The bees, apparently charged with applying the pro- * Kirby and Speuce observed bees very busy in collecting propolis from the tacamahaca-tree {Populus bahainifera). — lutrod., ii. 186. 94 INSECT ARCHITECTURE. polls within the cells, were easily distinguished from the multitude of Avorkers, by the direction of their heads to- wards the horizontal pane forming the roof of the hive, and on reaching it, they deposited their burthen nearly in the middle of intervals separating the combs : then they con- veyed the propolis to the real place of its destination. They suspended themselves by the claws of the hind legs to points of support, afforded by the viscosity of the pro- polis on the glass ; and, as it were, swinging themselves backwards and forwards, brought the heap of this substance nearer to the cells at each impulse. Here the bees employed their fore feet, which remained free, to sweep what the teeth had detaclied, and to unite the fragments scattered over the glass, which recovered all its transparency when the whole propolis was brought to the vicinity of the cells. " After some of the bees had smoothed down and cleaned out the glazed cells, feeling the way with their antennae, one desisted, and having approached a heap of propolis, drew out a thread with its teeth. This being broken oft', it was taken in the claws of the fore feet, and the bee, re- entering the cell, immediately placed it in the angle of two portions that had been smoothed, in which operation the fore feet and teeth were used alternately; but probably proving too clumsy, the thread was reduced and polished ; and we admired the accuracy with which it was adjusted when the work was completed. The insect did not stop here : returning to the cell, it prepared other parts of it to receive a second thread, for which we did not doubt that the heap would be resorted to. Contrary to our expecta- tion, however, it availed itself of the portion of the thread cut off on the former occasion, arranged it in the appointed place, and gave it all the solidity and finish of which it was susceptible. Other bees concluded the work which the first had begun : and the sides of the cells were speedily secured with threads of propolis, while some were also put on the orifices ; but we could not seize the moment when they were varnished, though it may be easily conceived how it is done."* *' Hubcr on Bees, p. 408. iiiVE-r.EES. 95 This is not the only use to which bees apply the propolis. They are extremely solicitous to remove such insects or foreign bodies as happen to get admission into the hive. When so light as not to exceed their powers, they first kill the insect with their stings, and then drag it out with their teeth. But it sometimes happens, as was first observed by Maraldi, and since by Eeaumur and others, that an ill-fated snail creeps into the hive : this is no sooner perceived than it is attacked on all sides, and stung to death. But how are the bees to carry out so heavy a burthen? Such a labour would be in vain. To prevent the noxious smell which would arise from its putrefaction, they immediately embalm it, by covering every part of its body with piopolis, through which no effluvia can escape. When a snail with a shell gets entrance, to dispose of it gives much less trouble and expense to the bees. As soon as it receives the first wound from a sting, it naturally retires within its shell. In this case, the bees, instead of pasting it all over Avith propolis, content themselves with gluing all round the margin of the shell, which is sufficient to render the animal for ever immovabl}^ fixed. Mr. Knight, the learned and ingenious President of the Horticultural Society, discovered by accident an artificial substance, more attractive than any of the resins experi- mentally tried by Eeaumur. Having caused the decorti- cated part of a tree to be covered with a cement composed of bees'-wax and turpentine, he observed that this was frequented by hive-bees, who, finding it to be a very good propolis ready made, detached it from the tree with their mandibles, and then, as usual, passed it from the first leg to the second, and so on. When one bee had thus collected its load, another often came behind and despoiled it of all it had collected ; a second and a third load were frequently lost in the same manner ; and yet the patient insect pursued its operations without manifesting any signs of anger* Probably the latter circumstance, at which Mr. Knight seems to have been surprised, was nothing more than an *:= Philosopliical Trans, for 1807, p. 242. 90 INSECT ARCHITPXTURE. instance of the division of laboiu' so strikingly exemplified in every part of tlie economy of bees. It may not be out of place here to describe the apparatus with which the worker-bees are provided for the purpose of carrying the propolis as well as the pollen of flowers to the hive, and which has just been alluded to in the observations of Mr. Knight, The shin or middle portion of the hind 23air of legs is actually formed into a triangular basket, admirably adapted to this design. The bottom of this basket is composed of a smooth, shining, horn-like substance, hollowed out in the substance of the limb, and surrounded with a margin of strong and thickly-set biistles. ^Miatever structure of the legs of the Bee, for carrying projiolis ami pollen, magnified. materials, therefore, may be placed by the bee in the interior of this basket, are secured from falling out by the bristles around it, whose elasticity will even allow the load to be heaped bej^ond their points without letting it fall. In the case of propolis, when the bee is loading her sin- gular basket, she first kneads the piece she has detached with her mandibles, till it becomes somewhat dry and less adhesive, as otherwise it would stick to her limbs. This , preliminary process sometimes occupies nearly half an hour. She then passes it backwards by means of her feet to the cavit}^ of her basket, giving it two or three pats to make it adhere ; and when she adds a second portion to the first, she often finds it necessary to pat it still hai dcr. AVhen she HIVE-BEES. 97 has procured as mucli as the basket will conveniently hold, she flies off with it to the hive. The Building of the Cells. The notion commonly entertained respecting glass hives is altogether erroneous. Those w^ho are unacquainted with bees imagine that, by means of a glass hive, all their pro- ceedings may be easily watched and recorded ; but it is to be remembered that bees are exceedingly averse to the intrusion of light, and their first operation in such cases is to close up every chink by which light can enter to dis- turb them, either by clustering together, or by a plaster composed of propolis. It consequently requires consider- able management and ingenuity, even with the aid of a glass hive, to see them actually at w^ork. M. Huber employed a hive with leaves, which opened in the manner of a book; and for some purposes he used a glass box, inserted in the body of the hive, but easily brought into view by means of screws. But no invention hitherto contrived is sufficient to ob- viate every difficulty. The bees are so eager to afford mutual assistance, and for this purpose so many of them crowd together in rapid succession, that the operations of individuals can seldom be traced. Though this crowding, however, appears to an observer to be not a little con- fused, it is all regulated with admirable order, as has been ascertained by Keaumur and other distinguished naturalists. When bees begin to build the hive, they divide them- selves into bands, one of which produces materials for the structure ; another works upon these, and forms them into a rough sketch of the dimensions and partitions of the cells. All this is completed by the second band, who examine and adjust the angles, remove the superfluous wax, and give the work its necessary perfection ; and a third band brings pro- visions to the labourers, who cannot leave their work. But no distribution of food is made to those whose charge, in collecting propolis and pollen, calls them to the field, because it is supposed they will hardly forget themselves ; H 98 INSECT ARCHITECTURE. neither is any allowance made to those who begin the architecture of the cells. Their province is very trouble- some, because they are obliged to level and extend, as well as cut and adjust the wax to the dimensions required ; but then they soon obtain a dismission from this labour, and retire to the fields to regale themselves with food, and wear off their fatigue with a more agreeable employment. Those who succeed them, draw their mouth, their feet, and the extremity of their body, several times over all the work, and never desist till the whole is polished and completed ; and as they frequently need refreshments, and yet are not permitted to retire, there are waiters always attending, who serve them with provisions when they require them. The labourer Avho has an appetite, bends down his trunk before the caterer to intimate that he has an inclination to eat, upon which the other opens his bag of honey, and pours out a few drops : these may be distinctly seen rolling through the whole of his trunk, which insensibly swells in every part the liquor flows through. When this little repast is over, the labourer returns to his work, and his body and feet repeat the same motions as before.* Before they can commence building, however, when a colony or swarm migrates from the original hive to a new situation, it is necessary first to collect propolis, with which every chink and cranny in the place where they mean to build may be carefully stopped up ; and secondly, that a quantity of wax be secreted by the wax- workers, to form the requisite cells. The secretion of wax, it would appear, goes on best when the bees are in a state of repose ; and the wax-workers, accordingly, suspend themselves in the interior in an extended cluster, like a curtain which is composed of a series of intertwined festoons or garlands, crossing each other in all directions — the uppermost bee maintaining its position by laying hold of the roof with its fore legs, and the succeeding one by laying hold of the hind legs of the first. " A person," says Eeaumur, " must have been born devoid of curiosity rot to take interest in the investigation * Spectacle de la Nature, tome i. IIIVE-BEES. 99 of such wonderful proceedings." Yet Eeaumur himself seems not to have understood that the bees suspended them- selves in this manner to secrete wax, but merely, as he imagined, to recruit themselves by rest for renewing their labours. The bees composing the festooned curtain are individually motionless ; but this curtain is, notwithstand- Curtain of \Vax-\voiker& secietiiig wax. ing, kept moving by the proceedings in the interior; for the nurse-bees never form any portion of it, and continue their activity— a distinction with which Keaumur was unacquainted. Although there are many thousand labourers in a hive, 100 IXSECT ARCHITECTURE. they do not commence foundations for combs in several places at once, but wait till an individual bee has selected a site, and laid the foundation of a comb, which serves as a directing mark for all that are to follow. Were we not expressly told by so accurate an observer as Huber, we might hesitate to believe that bees, though united in what appears to be an harmonious monarchy, are strangers to subordination, and subject to no discipline. Hence it is, that though many bees work on the same comb*, they do not appear to be guided by any simultaneous impulse. The stimulus which moves them is successive. An indi- vidual bee commences each operation, and several others successively apply themselves to accomplish the same purpose. Each bee appears, therefore, to act individually, either as directed by the bees preceding it, or by the state of advancement in which it finds the work it has to proceed with. If there be anything like unanimous consent, it is the inaction of several thousand workers while a single individual proceeds to determine and lay down the foun- dation of the first comb. Reaumur regrets, that, though he could b}^ snatches detect a bee at work in founding cells or perfecting their structure, his observations were generally interrupted by the crowding of other bees between him and the little builder. He was therefore compelled rather to infer the different steps of their procedure from an ex- amination of the cells when completed, than from actual observation. The ingenuity of Huber, even under all the disadvantages of blindness, succeeded in tracing the minutest operations of the workers from the first waxen plate of the foundation. We think the narrative of the discoverer's experiments, as given b}^ himself, will be more interesting than any abstract of it which we could fur- nish : — " Having taken a large bell-shaped glass receiver, we glued thin wooden slips to the arch at certain intervals, because the glass itself was too smooth to admit of the bees supporting themselves on it. A swarm, consisting of some thousand workers, several hundred males, and a fertile queen, was introduced, and they soon ascended to HIVE-BEES. 101 the top. Those first gaining the slips fixed themselves there by the fore-feet ; others, scrambling up the sides, joined them, by holding their legs with their own, and they thus formed a kind of chain, fastened by the two ends to the upper parts of the receiver, and served as ladders or a bridge to the workers enlarging their number. The latter were united in a cluster, hanging like an inverted pyramid from the top to the bottom of the hive. " The country then affording little honey, v/e provided the bees with syrup of sugar, in order to hasten their labour. They crowded to the edge of a vessel containing it ; and, having satisfied themselves, returned to the group. We were now struck with the absolute repose of this hive, contrasted with the usual agitation of bees. Meanwhile, the nurse-bees alone went to forage in the country ; they returned with pollen, kept guard at the entrance of the hive, cleansed it, and stopped up its edges with propolis. The wax-workers remained motionless above fifteen hours : the curtain of bees, consisting always of the same indi- viduals, assured us that none replaced them. Some hours later, we remarked that almost all these individuals had wax scales under the rings ; and next day this phenomenon was still more general. The bees forming the external layer of the cluster, having now somewhat altered their position, enabled us to see their bellies distinctly. By the projection of the wax scales, the rings seemed edged with white. The curtain of bees became rent in several places, and some commotion began to be observed in the hive. " Convinced that the combs would originate in the centre of the swarm, our whole attention was then directed towards the roof of the glass. A worker at this time de- tached itself from one of the central festoons of the cluster, separated itself from the crowd, and, with its head, drove away the bees at the beginning of the row in the middle of the arch, turning round to form a space an inch or more in diameter, in which it might move freely. It then fixed itself in the centre of the space thus cleared. " The worker now employing the pincers at the joint of one of the third pair of its limbs, seized a scale of wax 102 INSECT ARCHITECTURE. projecting from a ring, and brought it forward to its mouth with the claws of its fore-legs, Avhere it appeared in a vertical position. We remarked that, with its claws, it turned the wax in every necessary direction ; that the edge of the scale was immediately broken down, and the fragments having been accumulated in the hollow of the mandibles, issued forth like a very narrow ribbon, impreg- nated with a froth}^ liquid by the tongue. The tongue itself assumed the most varied shapes, and executed the most complicated operations, — being sometimes flattened like a Wax-worker laying the foundation of the first Cell. trowel, and at other times pointed like a pencil ; and, after imbuing the whole substance of the ribbon, pushed it forward again into the mandibles, whence it was drawn out a second time, but in an opposite direction. " At length the bee applied these particles of wax to the vault of the hive, where the saliva impregnating them promoted their adhesion, and also communicated a white- ness and opacity which were wanting when the scales were detached from the rings. ' Doubtless this process was to give the wax that ductility and tenacity belonging to its perfect state. The bee then separated those por- tions not yet applied to use with its mandibles, and with the same organs afterwards arranged them at pleasure. The founder bee, a name appropriated to this worker, repeated the same operation, until all the fragments, worked up and impregnated with the fluid, were attached to the vault, when it repeated the preceding operations on the part of the scale yet kept apart, and again united to the rest what was obtained from it. A second and third scale were similarly treated b}^ the same bee ; yet the work was only sketched ; for the worker did nothing but accumulate the particles of wax together. Meanwhile the founder, HIVE-BEES. 101 quitting its position, disappeared amidst its companions. Another, with wax under the rings, succeeded it, which, suspending itself to the same spot, withdrew a scale by the pincers of the hind legs, and passing it through its mandibles, prosecuted the work ; and taking care to make its deposit in a line with the former, it united their ex- tremities. A third worker detaching itself from the in- terior of the cluster, now came and reduced some of the scales to paste, and put them near the materials accumu- lated by its companions, but not in a straight line. Ano- Curtain of Wax-workers (see p. 99). ther bee, apparently sensible of the defect, removed the misplaced wax before our eyes, and carrying it to the former heap, deposited it there, exactly in the order and direction pointed out. " From all these operations was produced a block of a rugged surface, hanging down from the arch, without any 104 IXSECT ARCHITECTURE. perceptible angle, or any traces of cells. It was a simple wall, or ridge, running in a straight line, and withont the least inflection, two-thirds of an inch in length, about two- thirds of a cell, or two lines, high, and declining towards the extremities. We have seen other foundation w^alls from an inch to an inch and a half long, the form being always the same ; but none ever of greater height. " The vacuity in the centre of the cluster had permitted us to discover the first manoeuvres of the bees, and the art with which they laid the foundations of their edifices. However, it was filled up too soon for our satisfaction ; for workers collecting on both faces of the wall obstructed our view of their further operations." * * Hiiber on Bees, p. 858. t ( 105 ) CHAPTER VI. ARCHITECTURE OF THE BEE-HIVE CONTINUED FORM OF THE CELLS. The obstruction of which M. Huber complains only ope- rated as a stimulus to his ingenuity in contriving how he might continue his interestiug observations. From the time of Pappus to the present day, mathematicians have applied the principles of geometry to explain the construc- tion of the cells of a bee -hive ; but though their extra- ordinary regularity, and wonderfully-selected form, had so often been investigated by men of the greatest talent, and skilled in all the refinements of science, the process by which they are constructed, involving also the causes of their regularity of form, had not been traced, till ]\I. Huber devoted himself to the inquiry. As the wax-workers secrete only a limited quantity of wax, it is indispensably requisite that as little as possible of it should be consumed, and that none of it should be wasted. Bees, therefore, as M. Eeaumur well remarks,* have to solve this difficult geometrical problem : — a quan- tity of wax being given, to form of it similar and equal cells of a determinate capacity, but of the largest size in proportion to the quantity of matter employed, and dis- posed in such a manner as to occupy the least possible space in the hive. This problem is solved by bees in all its conditions. The cylindrical form would seem to be best adapted to the shape of the insect ; but had the cells been cylindrical, they could not have been applied to each other without leaving a vacant and superfluous space between every three contiguous cells. Had the cells, on the other hand, been square or triangular, they might have been con- * Reaumin, vol. v. p. 380. 106 INSECT ARCHITECTURE. striicted without unnecessary vacancies ; but these forms would have both required more material and had been very unsuitable to the shape of a bee's body. The six- sided form of the cells obviates every objection; and while it fulfils the conditions of the problem, it is. equally adapted with a cylinder to the shape of the bee. M. Keaumur further remarks, that the base of each cell, instead of forming a plane, is usually composed of three pieces in the shape of the diamonds on playing cards, and placed in such a manner as to form a hollow pyramid. This structure, it may be observed, imparts a greater degree of strength, and, still keeping the solution of the problem in view, gives a great capacity with the smallest expendi- ture of material. This has actually, indeed, been ascertained b}^ mathematical measurement and calculation. Maraldi, the inventor of glass hives, determined, by minutely measuring these angles, that the greater were 109° 28', and the smaller 70° 32' ; and M. Eeaumur, being -desirous to know why these particular angles are selected, requested M. Koenig, a skilful mathematician (^dthout informing him of his design, or telling him of Maraldi's researches), to determine by calculation what ought to be the angle of a six-sided cell, with a concave pp-amidal base, formed of three similar and equal rhomboid plates, so that the least possible matter should enter into its construction. By em- ploying what geometricians denominate the wfinitesimal calculus, M. Koenig found that the angles should be 109^ 26' for the greater, and 70^ 34' for the smaller, or about two- sixtieths of a degree, more or less, than the actual angles made choice of by bees. The equality of inclination in the angles has al so been said to facilitate the construction of the cells. M. Huber adds to these remarks, that the cells of the first row, by which the whole comb is attached to the roof of a hive, are not like the rest ; for, instead of six sides, they have only five, of which the roof forms one. The base, also, is in these diiferent, consisting of three pieces on the face of the comb, and on the other side of two : one of these only is diamond-shaped, while the other two are HIVE-BEES. 107 of an irregular four-sided figure. This arrangement, by bringing the greatest number of points in contact with the interior surface, insures the stability of the comb. It may, however, be said not to be quite certain, that Eeaumur and others have not ascribed to bees the merit of ingenious mathematical contrivance and selection, when the construction of the cells may more probably originate in the form of their mandibles and the other instruments employed in their operations. In the case of other insects, we have, both in the preceding and subsequent pages of this volume, repeatedly noticed, that they use their bodies, or parts thereof, as the standards of measurement and Arrangement of Cells. modelling ; and it is not impossible that bees may proceed on a similar principle. M. Huber replies to this objection, that bees are not provided with instruments corresponding to the angles of their cells ; for there is no more resem- blance between these and the form of their mandibles, than between the chisel of the sculptor and the work which he produces. The head, he thinks, does not furnish any better explanation. He admits that the antennae are very flexible, so as to enable the insects to follow the outline of every object ; but concludes that neither their structure, nor that of the limbs and mandibles, are adequate to explain the form of the cells, though all these are employed in the operations of building, — the effect, according to him, de- pending entirely on the object which the insect proposes. We shall now follow M. Huber in the experiments which he contrived, in order to observe the operations of the bees 108 INSECT ARCHITECTURE. subsequent to their laying a foundation for the first cell ; and we shall again quote from his own narrative : — " It appeared to me," he says, " that the onl}^ method of isolating the architects, and bringing them individually into view, would be to induce them to change the direc- tion of their operations and work upwards. " I had a box made twelve inches square and nine deep, with a moveable glass lid. Combs, full of brood, honey, and pollen, were next selected from one of my leaf -hives, as containing what might interest the bees, and being cut into pieces a foot long, and four inches deep, they were arranged vertically at the bottom of the box, at the same intervals as the insects themselves usually leave between them! A small slip of wooden lath covered the upper edge of each. It was not probable that the bees woidd attempt to. found new combs on the glass roof of the box, because it5 smoothness precluded the swarm from adhering to it ; therefore, if disposed to build, they could do so over the slips resting on the combs, which left a vacuity five inches high above them. As we had foreseen, the swarm with which this box was peopled established itself among the combs below. We then observed the nurse-bees displaying their natural activity. They dispersed them- selves throughout the hive, to feed tlie young grubs, to clear out their lodgment, and adapt it for their convenience. Certainly, the combs, which were roughly cut to fit the bottom of the box, and in some parts damaged, appeared to them shapeless and misplaced ; for they speedily com- menced their reparation. They beat down the old wax, kneaded it between their teeth, and thus formed binding materials to consolidate them. We were astonished beyond expression by such a multitude of workers employed at once in labours to which it did not appear they should have been called, at their coincidence, their zeal, and their prudence. " But it was still more wonderful, that about half the numerous population took no part in the proceedings, remaining motionless, while the others fulfilled the func- tions required. The wax-workers, in a state of absolute IIIVE-BEES. 109 repose, recalled our former observations. Gorged with the honey we had put within their reach, and continuing in this condition during twenty -four hours, wax was formed under their rings, and was now ready to be put in opeia- tion. To our great satisfaction, we soon saw a little foun- dation wall rising on one of the slips that we had prepared to receive the superstructure. No obstacle was offered to the progress of our observations ; and for the second time we beheld both the undertaking of the founder-bee, and the successive labours of several wax-workers, in forming the foundation wall. ^Vould that my readers could share the interest which the view of these architects inspired ! " This foundation, originally very small, was enlarged as the work required ; while they excavated on one side a hollow, of about the width of a common cell, and on the opposite surface two others somewhat more elongated. The middle of the single cell corresponded exactly to the partition separating the latter : the arches of these excava- n|rgi||/ |j|ipnir-f|^ Foundation-wall enlarged, and the Cells commenced. tions, projecting by the accumulation of wax, were con- verted into ridges in a straight line ; whence the cells of the first row were composed of five sides, considering the slip as one side, and those of the second row, of six sides. " The interior conformation of the cavities, apparentl}^, was derived from the position of their respective outlines. It seemed that the bees, endowed with an admirable deli- cacy of feeling, directed their teeth principally to the place where the wax was thickest ; that is, the parts where other workers on the opposite side had accumulated it ; and this explains why the bottom of the cell is excavated in an angular direction behind the projection on the sides of which the sides of the corresponding cells are to rise. The largest of the excavations, which M^as opposite to three 110 INSECT AECHITECTURE. others, was divided into three parts, while the excavations of the first row on the other face, applied against this one, were composed of only two. " In consequence of the manner in which the excava- tions were opposed to each other, those of the second row, and all subsequent, partially applied to three cavities, were composed of three equal diamond-shaped lozenges. I may here remark, that each part of the labour of bees appears the natural result of what has preceded it; therefore, chance has no share in these admirable combinations. " A foundation-wall rose above the slip like a minute vertical partition, five or six lines long, two lines high, but only half a line in thickness ; the edge circular, and the surface rough. Quitting the cluster among the combs, a nurse-bee mounted the slip, turned around the block, and visiting both sides, began to work actively in the middle. It removed as much wax with its teeth as might equal the diameter of a common cell ; and after kneading and moisten- ing the particles, deposited them on the edge of the excava- tion. This insect having laboured some seconds, retired, and was soon replaced by another ; a third continued the work, raising the margin of the edges, now projecting from the cavity, and with assistance of its teeth and feet fixing the particles, so as to give these edges a straighter form. More than twenty bees successively participated in the same work; and when the cavity was little above a line and a half in height, though equalling a cell in width, a bee left the swarm, and after encircling the block, com- menced its operations on the opposite face, where yet un- touched. But its teeth acting only on one half of this side, the hollow which it formed was opposite to only one of the slight prominences bordering the first cavity. Nearly at the same time another worker began on the right of the face that had been untouched, wherein both were occupied in forming cavities which may be designed the second and third ; and they also were replaced by substitutes. These two latter cavities were separated only by the common margin, framed of particles of wax withdrawn from them ; which margin corresponded with tlie centre of the cavity on HIVE -BEES. Ill the opposite surface. The foundation-wall itself was still of insufficient dimensions to admit the full diameter, of a cell: but while the excavations were deepened, wax- workers, extracting their scales of wax, applied them in enlarging its circumference ; so that it rose nearly two lines further around the circular arch. The nurse-bees, which appeared more especially charged with sculpturing the cells, being then enabled to continue their outlines, pro- longed the cavities, and heightened their margins on the new addition of wax. " The arch, formed by the edge of each of these cavities, was next divided as by two equal chords, in the line of which the bees formed stages or projecting borders, or margins meeting at an obtuse angle : the cavities now had four margins, two lateral and perpendicular to the sup- porting slip, and two oblique, which were shorter. " Meantime, it became more difficult to follow the ope- rations of the bees, from their frequently interposing their heads between the eye of the observer and the bottom of the cell ; but the partition, whereon their teeth laboured had become so transparent, as to expose what passed on the other side. " The cavities, of which we speak, formed the bottom of the first three cells ; and while the bees engaged were advancing them to perfection, other workers commenced sketching a second row of cells above the first, and partly behind those in front — for, in general, their labour pro- ceeds by combination. We cannot say, ' When bees have finished this cell, they will begin new ones ;' but, ' while particular workers advance a certain portion, we are certain that others will carry on the adjacent cells.' Further, the work begun on one face of the comb is already the com- mencement of that which is to follow on the reverse. All this depends on a reciprocal relation, or a mutual con- nexion of the parts, rendering the whole subservient to each other. It is undoubted, therefore, that slight irregu- larities on the front will affect the form of the cells on the back of the comb." * * Huber on Bees, p. 308. 112 INSECT ARCHITECTURE. When tliey have in this manner worked the bottoms of the first row of cells into the required forms, some of the nurse-bees finish them by imparting a sort of polish, while others proceed to cut out the rudiments of a second row from a fresh wall of wax which has been built in the mean- while by the wax-workers, and also on the 02:)posite side of this wall ; for a comb of cells is always double, being arranged in two layers, placed end to end. The cells of this second row are engrafted on the borders of cavities hollowed out in the wall, being founded by the nurse-bees, brinofino; the contour of all the bottoms, w^hich is at first unequal, to the same level ; and this level is kept uniform in the margins of ,tlie cells till they are completed. At first sight nothing appears more simple than adding wax to the margins ; but from the inequalities occasioned by the shape of the bottom, the bees must accumulate wax on the depressions, in^ order to bring them to a level. It follows accordingly that the surface of a new comb is not quite flat, there being a progressive slope produced as the work proceeds, and the comb being therefore in the form of a lens, the thickness decreasing towards the edge, and the last-formed cells being shallower or shorter than those preceding them. So long as there is room for the enlarge- ment of the comb, this thinning of its edge may be re- marked ; but as soon as the space within the hive prevents its enlargement, the cells are made equal, and two flat and level surfaces are produced. M. Huber observed, that while sketching the bottom of a cell, before there was any upright margin on the reverse, their pressure on the still soft and flexible wax gave rise to a projection, which sometimes caused a breach of the partition. This, however, was soon repaired, but a slight prominence always remained on the opposite surface, to the right and left of which they placed themselves to begin a new excavation ; and they heaped up part of the materials between the two flutings formed by their labour. The ridge thus formed becomes a guide to the direction Avhich the bees are to follow for their vertical furrow of the front cell. HIVE-BEES. 113 We have already seen that the first cell determines the place of all that succeed it, and two of these are never, in ordinary circumstances, begun in different parts of the hive at the same time, as is alleged by some early writers. When some rows of cells, however, have been completed in the first comb, two other foundation-walls are begun, one on each side of it, at the exact distance of one-third of an inch, which is sufficient to allow two bees employed on the opposite cells to pass each other without jostling. These new w^alls are also parallel to the former; and two more are afterw^ards begun exterior to the second, and at the same parallel distance. The combs are uniformly enlarged, and lengthened in a progression proportioned to the priority of their origin ; the middle comb being alwaj'S advanced beyond the two adjoining ones by several row^s of cells, and these again beyond the ones exterior to them. Did the bees lay the foundations of all their combs at the same time, they would not find it easy to preserve paral- lelism and an equality in their distances. It may be re- marked further, that beside the vacancies of half an inch between the cells, which form what w^e call the highways of the community, the combs are pierced in several places with holes which serve as postern-gates for easy communi- cation from one to another, to prevent loss of time in going round. The equal distance between the combs is of more importance to the w^elfare of the hive than might at first appear ; for were they too distant, the bees would be so scattered and dispersed, that they could not reciprocally communicate the heat indispensable for hatching the eggs and rearing the young. If the combs, on the other hand, were closer, the bees could not traverse the intervals with the freedom necessary to facilitate the work of the hive. On the approach of winter, they sometimes elongate the cells which contain honey, and thus contract the intervals between the combs. But this expedient is in prej)aration for a season when it is important to have copious magazines, and when, their activity being relaxed, it is unnecessary for their communications to be so spacious and free. On the return of spring, the bees hasten to contract the elon- 1 114 IXSECT ARCHITECTURE. gated cells, that tliey may become fit for receiving the eggs which the queen is about to deposit, and in this manner they re-establish the regular distance.* We are indebted to the late Dr. Barclay of Edinburgh, well known as an excellent anatomist, for the discovery that each cell in a honeycomb is not simply composed of one wall, but consists of two. We shall give the account of his discovery in his own words : — " Having inquired of several naturalists whether or not they knew any author who had mentioned that the par- titions between the cells of the honeycomb were double, and whether or not they had ever remarked such a struc- ture themselves, and they having answered in the nega- tive, I now take the liberty of presenting to the Society pieces of honeycomb, in which the young bees had been reared, upon breaking which, it will be clearly seen that the partitions between different cells, at the sides and the base, are all douhle ; or, in other words, that each cell is a distinct, separate, and in some measure an independent structure, agglutinated only to the neighbouring cells ; and that when the agglutinating substance is destoyed, each cell may be entirely separated from the rest. "I have also some specimens of the cells formed by wasps, which show that the partitions between them are also double, and that the agglutinating substance between them is more easily destroyed than that between the cells of the bee."f Irregularities in their Workmanship. Though bees, however, work with great uniformity when circumstances ftivour their operations, they may be com- pelled to vary their proceedings. M. Huber, made several ingenious experiments of this kind. The following, men- tioned by Dr. Bevan, was accidental, and occurred to his friend Mr. Walond. " Inspecting his bee-boxes at the end of October, 1817, he perceived that a centre comb, burthened with honey, had separated from its attachments, and was * Huber on Bees, p. 220. t Memoirs of the Wernerian Xut. Hist. Soc. vol. ii. p. 2G0. IIIVE-BEES. 115 leaning against another comb so as to prevent the passage of the bees between them. This accident excited great activity in the colony ; but its natnre conkl not be ascer- tained at the time. At the end of a week, the weather being cold, and the bees clustered together, Mr. Walond observed, through the window of the box, that they had constructed two horizontal pillars betwixt the combs alluded to ; and had removed so much of the honey and wax from the top of each as to allow the passage of a bee : in about ten days more there was an uninterrupted thoroughfare ; the detached comb at its upper part had been secured by a strong barrier, and fastened to the window with the spare wax. This being accomplished, the bees removed the horizontal pillars first constructed, as being of no further use."* A similar anecdote is told by M. Huber. " During the winter," says he, " a comb in one of my bell-glass hives, having been originally insecure, fell down, but preserved its position parallel to the rest. The bees -were unable to fill up the vacuity left above it, because they do not build combs of old wax, and none new could be then obtained. At a more favourable season they would have engrafted a new comb on the old one ; but now their provision of honey could not be spared for the elaboration of this substance, which induced them to ensure the stability of the comb by another process. " Crowds of bees taking wax from the lower part of other combs, and even gnawing it from the surface of the orifices of the deepest cells, they constructed so many irregular pillars, joists, or buttresses, between the sides of the fallen comb, and others on the glass of the hive. All these were artificially adapted to localities. Neither did they confine themselves to repairing the accidents which their works had sustained. They seemed to profit by the warning to guard against a similar casualty. "The remaining combs were not displaced; therefore, while solidly adhering by the base, we were greatly sur- prised to see the bees strengthen their principal fixtures * Bevau on Bees, p. 826. 116 INSECT ARCHITECTURE. TNdtli old wax. They rendered them much thiclver than before, and fabricated a number of new connections, to unite them more firmly to each other and to the sides of their dwelling. All this passed in the middle of January, a time that these insects commonly keep in the upper part of their hive, and when work is no longer seasonable."* M. Huber the younger shrewdly remarks, that the tend- ency to symmetiy observable in the architecture of bees does not hold so much in small details as in the whole work, because they are sometimes obliged to adapt them- selves to particular localities. One irregidarity leads on to another, and it commonly arises from mere accident, or from design on the part of the proprietor of the bees. By allowing, for instance, too little interval between the spars for receiv- ing the foundation of the combs, the structure has been continued in a particular direction. The bees did not at first appear to be sensible of the defect, though they after- wards began to suspect their error, and were then observed to change their line of work till they gained the customary distance. The cells having been by this change of direc- tion in some degree curved, the new ones which were com- menced on each side of it, by being built everywhere parallel to it, partook of the same curvature. But the bees did not relish such approaches to the " line of beauty," and exerted themselves to bring their buildings again into the regular form. In consequence of several irregularities which they wished to correct, the younger Huber has seen bees depart from their usual practice, and at once lay on a spar two founda- tion walls not in the same line. They could consequently neither be enlarged without obstructing both, nor from their position could the edges unite had they been prolonged. The little architects, however, had recourse to a very ingenious contrivance : they curved the edges of the two combs, and brought them to unite so neatly that they could be both prolonged in the same line with ease ; and when carried to some little distance, their surface became quite uniform and level. *' Huber on Bees, p. 41 G. HIVE-BEES. in " Having seen bees," says the elder Hnber, " work both Tip and down, I wished to try to investigate whether we could compel them to construct their combs in any other direction. We endeavoured to puzzle them with a hive glazed above and below, so that they had no place of support but the upright sides of their dwelling ; but, betaking them- selves to the upper angle, they built combs perpendicular to one of these sides, and as regularly as those which they usually build under a horizontal surface. The foundations were laid on a place which does not serve naturally for the base, yet, except in the difference of direction, the first row of cells resembled those in ordinary hives, the others being distributed on both faces, while the bottoms alternately corresponded with the same symmetry. I put the bees to a still greater trial. As they now testified their inclination to carry their combs, by the shortest way, to the opposite side of the hive (for they prefer uniting them to Avood, or a surface rougher than glass), I covered it with a pane. Whenever this smooth and slippery substance was inter- posed between them and the wood, they departed from the straight line hitherto followed, and bent the structure of their comb at a right angle to what was already made, so that the prolongation of the extremity might reach another side of the hive, which had been left free. " Vaiying this experiment in several ways, I saw the bees constantly change the direction of their combs, when I presented to them a surface too smooth to admit of their clustering on it. They always sought the wooden sides. I thus compelled them to curve the combs in the strangest shapes, by placing a pane at a certain distance from their edges. These results indicate a degree of instinct truly wonderful. They denote even more than instinct : for glass is not a substance against which bees can be warned by nature. In trees, their natural abode, there is nothing that resembles it, or with the same polish. The most singular part of their proceeding is changing the direction of the work before arriving at the surface of the glass, and while yet at a distance suitable for doing so. Do they antici- pate the inconvenience which would attend any other mode 118 INSECT ARCHITECTURE. of building ? Xo less curious is tlie plan adopted by the bee for producing an angle in the combs : the wonted fashion of their woik, and the dimensions of the cells, must be altered. Therefore, the cells on the upper or convex side of the combs are enlarged ; they are constructed of three or four times the width of those on the opposite surface. How can so many insects, occupied at once on the edges of the combs, concur in giving them a common curvature from one extremity to the other ? How do they resolve on establishing cells so small on one side, while dimensions so enlarged are bestowed on those of the other ? And is it not still more singular, that they have the art of making a correspondence between cells of such reciprocal discrepance ? The bottom being common to both, the tubes alone assume a taper form. Perhaps no other insect has afforded a more decisive proof of the resources of instinct, when compelled to deviate from the ordinary course. " But let us study them in their natural state, and there we shall find that the diameter of their cells must be adapted to the individuals which shall be bred in them. The cells of males have the same figure, the same number of lozenges and sides, as those of workers, and angles of the same size. Their diameter is 3g lines, while those of woikers are only 2-|. "It is rarely that the cells of males occupy the higher part of the combs. They are generally in the middle or on the sides, where they are not isolated. The manner in which they are surrounded by other cells alone can explain how the transition in size is effected. When the cells of males are to be fabricated under those of workers, the bees make several rows of intermediate cells, whose diameter augments progressively, until gaining that proportion pro- per to the cells required; and in returning to those of workers, a lowering is observed in a manner corresponding. "Bees, in preparing the cells of males, previously esta- blish a block or luni}) of wax on the edge of their comb, thicker than is usually emj^loyed for those of workers. It is also made higher, otherwise the same order and symmetry could not be preserved on a larger scale. HIVE-BEES. 119 " Several naturalists notice the irregularities in the cells of bees as so many defects. What would have been their astonishment had the}^ observed that part of them are the result of calculation ? Had they followed the imperfection of their organs, some other means of compensating them would have been granted to the insects. It is much more surprising that they know how to quit the ordinary route, when circumstances demand the construction of enlarged cells ; and, after building thirty or forty rows of them, to return to the proper proportions from which they have departed by successive reductions. Bees also augment the dimensions of their cells when there is an opportunity for a great collection of honey. Not only are they then con- structed of a diameter much exceeding that of the common cells, but they are elongated throughout the whole space admitting it. A great portion of irregular comb contains cells an inch, or even an inch and a half, in depth. " Bees, on the contrary, sometimes are induced to shorten their cells. When wishing to prolong an old comb, whose cells have received their full dimensions, they gradually reduce the thickness of its edges, by gnawing down the sides of the cells, until they restore it to its original lenti- cular form. They add a waxen block around the whole circumference, and on the edge of the comb construct pyramidal bottoms, such as those fabricated on ordinary occasions. It is a certain fact, that a comb never is ex- tended in any direction unless the bees have thinned the edges, which are diminished throughout a sufficient space to remove any angular projection. " The law which obliges these insects partly to demolish the cells on the edges of the comb before enlarging it, unquestionably demands more profound investigation. How can we account for instinct leading them to undo what they have executed with the utmost care ? The wonted regular gradation, which may be necessary for new cells, subsists among those adjoining the edges of a comb recently con- structed. But afterwards, when those on the edge are deepened like the cells of the rest of the surface, the bees 120 IXSECT ARCHITECTURE. no longer preserve the decreasing gradation which is seen in the new combs."* The FiNisiiiXG of thr Cells. While the cells are building, they appear to be of a dull white colour, soft, even, though not smooth, and translucent ; but in a few days they become tinged with yellow, particu- larly on the interior surface ; and their edges, from being thin, uniform, and yielding, become thicker, less regular, more heavy, and so firm that they will bend rather than break. New combs break on the slightest touch. There is also a glutinous substance observable around the orifices of the yellow cells, of reddish colour, unctuous, and odoriferous. Threads of the same substance are applied all around the interior of the cells, and at the summit of their angles, as if it were for the purpose of binding and strengthening the walls. These yellow cells also require a much higher temperature of water to melt them than the white ones. It appeared evident, therefore, that another substance, different from wax, had been employed in varnishing the oiificcs and strengthening the interior of the cells. M. Huber, by numerous experiments, ascertained the resinous threads lining the cells, as well as the resinous substance around their orifice, to be propolis ; for he traced them, as we mentioned in our account of propolis, from the poplar buds where they collected it, and saw them apply it to the cells ; but the yellow colour is not imparted by pro- polis, to which it bears no analogy. We are, indeed, by no means certain what it is, though it was proved by experiment not to arise from the heat of the hives, nor from emanations of hone}^ nor from particles of j)ollen. Perhaps it may be ascribed to the bees rubbing their teeth, feet, and other parts of their body, on the surfaces where they seem to rest ; or to their tongue (haustellum) sweep- ing from right to left like a fine pliant pencil, when it appears to leave some sprinkling of a transparent liquid. *' Huber on Bees, p. 391. HIVE-BEES. 121 Beside painting and varnishing their cells in this manner, they take care to strengthen the weaker part of their edifice by means of a mortar composed of propolis and wax, and named pissoceros* by the ancients, who first observed it, though Eeanmnr was somewhat doubtful respecting the existence of such a composition. We are indebted to tlie shrewd observations of Huber for a reconcilement of the Eoman and the French naturalists. The details which he has given of his discovery are perhaps the most interesting in his delightful book. "Soon," he says, "after some new combs had been finished in a hive, manifest disorder and agitation pre- vailed among the bees. They seemed to attack their own works. The primitive cells, whose structure we had advan- mired, were scarcely recognizable. Thick and massy walls, heavy, shapeless pillars, were substituted for the slight partitions previously built with such regularity. The substance had changed along with the form, being com- posed apparently of wax and propolis. From the persever- ance of the workers in their devastation, we suspected that they proposed some useful alteration of their edifices ; and our attention was directed to the cells least injured. Several were yet untouched ; but the bees soon rushed precipitately on them, destroyed the tubes, broke down the wax, and threw all the fragments about. But we remarked, that the bottom of the cells of the first row were spared ; neither were the corresponding parts on both faces of the comb demolished at the same time. The bees laboured at them alternately, leaving some of the natural supports, other- wise the comb would have fallen down, which was not their object : they wished, on the contrary, to provide it a more solid base, and to secure its union to the vault of the hive, with a substance whose adhesive properties infinitely surpassed those of wax. The propolis employed on this occasion had been deposited in a mass over a cleft of the hive, and had hardened in drying, which probably rendered it more suitable for the purpose. But the bees experienced some difficulty in making any impression on it ; and we * From two Greek words, signifying j^itch and v:ax. 122 INSECT ARCHITECTURE. thouglit, as also had appeared to M. de Eeaumiir, that they softened it with the same frothy matter from the tongue which they use to render wax more ductile. " We very distinctly observed the bees mixing fragments of old wax with the propolis, kneading the two substances together to incoi-porate them ; and the compound was em- ployed in rebuilding the cells that had been destroyed. But they did not now follow their ordinary rules of archi- tecture, for they were occupied by the solidity of their edifices alone. Xight intervening, suspended our observa- tions, but next morning confirmed what we had seen. *' We find, therefore, that there is an epoch in the labour of bees, when the upper foundation of their combs is con- structed simply of wax, as Eeaumur believed ; and that, after all the requisite conditions have been attained, it is converted to a mixture of wax and propolis, as remarked by Pliny so many ages before us. Thus is the apj^arent contradiction between these two great naturalists explained. But this is not the utmost extent of the foresight of these insects. When they have plenty of wax, they make their combs the full breadth of the hive, and solder them to the glass or wooden sides, by structures more or less approach- ing the foiTQ of cells, as circumstances admit. But should the supply of wax fail before they have been able to give sufficient diameter to the combs whose edges are rounded, large intervals remain between them and the upright sides of the hive, and they are fixed only at the top. Therefore, did not the bees provide against it, by constructing great pieces of wax mixed with propolis, in the intervals, they might be boi-ne down by the weight of the honey. These pieeces are of irregular shape, strangely hollowed out, and their cavities void of symmetry." * It is remarked by the lively Abbe la Pluche, that the foundations of our houses sink with the earth on which they are built, the walls begin to stoop by degrees, they nod with age, and bend from their perpendicular ; — lodgers damage everything, and time is continually introducing some new decay. The mansions of bees, on the contrary, * Huber ou Bees, p. 415. HIVE-BEES. ' 123 grow stronger the oftener they change inhabitants. Every bee-grnb, before its metamorphosis into a nymph, fastens its skin to the partitions of its cell, but in such a manner as to make it correspond with the lines of the angle, and without in the least disturbing the regularity of the figui-e. During summer, accordingly, the same lodging may serve for three or four grubs in succession ; and in the ensuing season it may accommodate an equal number. Each grub never fails to fortify the panels of its chamber by arraying them with its spoils, and the contiguous cells receive a similar aug- mentation from its brethren.* Eeaumur found as many as seven or eight of these skins spread over one another : so that all the cells being incrusted with six or seven cover- ings, well dried and cemented with propolis, the whole fabric daily acquires a new degree of solidity. It is obvious, however, that by a repetition of this pro- cess the cell might be rendered too contracted ; but in such a case the bees know well how to proceed, by turning the cells to other uses, such as magazines for bee-bread and honey. It has been remarked, however, that in the hive of a new swarm, during the months of July and August, there are fewer small bees or nurse-bees than in one that has been tenanted four or five years. The workers, indeed, clean out the cell the moment that a young bee leaves its cocoon, but they never detach the silky film which it has previously spun on the walls of its cell. But though honey is deposited after the young leave the cells, the reverse also happens ; and accordingly, when bees are bred in con- tracted cells, they are by necessity smaller, and constitute, in fact, the important class of nurse-bees. We are not disposed, however, to go quite so far as an American periodical writer, who says, " Thus we see that the contraction of the cell may diminish the size of a bee, even to the extinction of life, just as the contraction of a Chinese shoe reduces the foot even to uselessness." f We know, on the contrary, that the queen bee will not deposit eggs in a cell either too small or too large for the proper rearing of * Spectacle de la Nature, vol. i. t North American Eev. Oct. 1828, p. Srjo. 124 INSECT ARCHITECTURE. the young. In the case of large cells, M. Huber took ad- vantage of a queen that was busy depositing the eggs of workers, to remove all the common cells adapted for their reception, and left only the large cells appropriated for males. As this was done in June, when bees are most active, he expected that they would have immediately repaired the breaches he had made ; but to his great surprise they did not make the slightest movement for that purpose. In the meanwhile the queen, being oppressed by her eggs, was obliged to drop them about at random, pre- ferring this to depositing them in the male cells, which she knew to be too large. At length she did deposit six eggs in the large cells, which were hatched as usual, three days after. The nurse-bees, however, seemed to be aware that they could not be reared there, and though they supplied them with food, did not attend to them regularly. M. Huber found that they had been all removed from the cells during the night, and the business both of laying and nursing was at a complete stand for tv^elve daj^s, when he supplied them again with a comb of small cells, which the queen almost immediately filled with eggs, and in some cells she laid five or six. The architecture of the hive, which we have thus de- tailed, is that of bees receiving the aid of human care, and having external coverings of a convenient form, prepared for their reception. In this country bees are not found in a wild state; though it is not uncommon for swarms to stray from their proprietors. But these stray swarms do not spread colonies through our woods, as they are said to do in America. In the remoter parts of that continent there are no wild bees. They precede civilization ; and thus when the Indians observe a swarm they say, " The white man is coming." There is evidence of bees having abounded in these islands, in the earlier periods of our history ; and Ireland is particularly mentioned by the Venerable Bede as being " rich in milk and honey." * The hive-bee has formed an object of economical culture * " Hibemia dives lactis ac mellis insula." — Btda, Hist. Eccles. i. 7. HIVE-BEES. 125 in Europe at least for two thousand years ; and Varro describes the sort of hives used in his time, 1870 years ago. We are not aware, however, that it is now to he found wild in the milder clime of Southern Europe, any more than it is in our own island. The wild bees of Palestine principally hived in rocks. " He made him," says Moses, " to suck honey out of the rock." * " With honey out of the rock," says the Psalmist, "should I have satisfied tliee."t In the caves of Salsette and Elephanta, at the present day, they hive in the clefts of the rocks and the recesses among the fissures, in such numbers, as to become very troublesome to visitors. Their nests hang in innumerable clusters.^ We are told of a little black stingless bee found in the island of Guadaloupe, which hives in hollow trees or in the cavities of rocks by the sea-side, and lays " up honey in cells about the size and shape of pigeons' eggs. These cells are of a black or deep violet colour, and so joined together as to leave no space between them. They hang in clusters almost like a bunch of grapes." § The follow- ing are mentioned by Lindley as indigenous to Brazil. " On an excursion towards Upper Tapagippe," says he, " and skirting the dreary woods which extend to the in- terior, I observed the trees more loaded with bees' nests than even in the neighbourhood of Porto Seguro. They consist of a ponderous shell of clay cemented similarly to martins' nests, swelling from high trees about a foot thick, and forming an oval mass full two feet in diameter. When broken, the wax is arranged as in our hives, and the honey abundant." |1 Captain Basil Hall found in South America, the hive of a honey-bee very different from the Brazilian, but nearly allied to, if not the same as, that of Guadaloupe. " The hive we saw opened," he says, "was only partly filled, which enabled us to see the economy of the interior to more advantage. The honey is not contained in the * Deut. xxxii. 13. t Psalm b^xxi. 16. X Forbes, Orien. Mem. i. § Amer. Q. Eev. iii. p. 383. 11 Eoy. Mil. Clirou. quoted in Kirby aud Spence. 126 IXSECT ARCHITECTURE. elegant "hexagonal cells of our hives, but in wax bags, not quite so large as an egg. These bags or bladders are hung round the sides of the hive, and appear about half full ; the quantity being probably just as great as the strength of the wax will bear without tearing. Those near the bottom, being better supported, are more filled than the upper ones. In the centre of the lower part of the hive we observed an irregularly-shaped mass of comb, furnished with cells like those of our bees, all con- taining young ones in such an advanced state, that, when we broke the comb, and let them out, they flew merrily away." Clavigero, in his ' History of Mexico,' evidently de- scribing the same species of bee, says it abounds in Yucatan, and makes the honey of Estabentum, the finest in the world, and which is taken every two months. He men- tioned another species of bee, smaller in size, and also without a sting, which forms its nest of the shape of a sugarloaf, and as large or larger. These are suspended from trees, particularly from the oak, and are much more populous than our common hives. Wild honey-bees of some species appear also to abound in Africa. Mr. Park, in his second volume of travels, tells us that some of his associates imprudent!}^ attempted to rob a numerous hive of its honey, when the exasperated bees, rushing out to defend their property, attacked their assailants with great fury, and quickly compelled the whole company to fly. At the Cape of Good Hope the bees themselves must be less formidable, or more easily managed, as their hives are sought for with avidity. Nature has there provided man with a singular and very eflicient assistant in a bird, most appropriately named the honey-guide (^Indicator major ^ ViEiLLOT ; Cucidus indicator, Latham). The honey-guide, it is said, so far from being alarmed at the presence of man, appears anxious to court his acquaintance, and flits from tree to tree with an expressive note of invitation, the meaning of which is well known both to the colonists and the Hottentots. A person thus invited by the honey-guide HIVE-BEES. 127 seldom refuses to follow it onward till it stops, as it is certain to do, at some hollow tree containing a bee-hive, usually well stored with honey and wax. It may be that the bird finds itself inadequate to the attack of a legion of bees, or to penetrate into the interior of the hive, and is thence led to invite an agent more powerful than itself. The person invited, indeed, always leaves the bird a share of the spoil, as it would be considered sacrilege to rob it of its due, or in any way to injure so useful a creature. The Americans, who have not the African honey-guide, employ several well-known methods to track bees to their hives. One of the most common though ingenious modes is to place a piece of bee-bread on a flat surface, a tile for instance, surrounding it with a circle of wet white paint. The bee, whose habit it is always to alight on the edge of any plane, has to travel through the paint to reach the bee- bread. AVhen, therefore, she flies off, the observer can track her by the white on her body. The same operation is repeated at another place, at some distance from the first, and at right angles to the bee-line just ascertained. The position of the hive is easily determined, for it lies in the angle made by the intersection of the bee-lines. Another method is described in the ' Philosophical Trans- actions for 1721.' The bee-hunter decoys, by a bait of honey, some of the bees into his trap, and when he has secured as many as he judges will suit his purpose, he incloses one in a tube, and, letting it fly, marks its course by a pocket-compass. Departing to some distance, he liberates another, observes its course, and in this manner determines the position of the hive, upon the principle already detailed. These methods of bee-hunting depend upon the insect's habit of always flying in a right line to its home. Those who have read Cooj^er's tale of the ' Prairie ' must well remember the character of the bee-hunter, and the expression of " lining a bee to its hive." In reading these and similar accounts of the bees of distant parts of the world, we must not conclude that the descriptions refer to the same species as the common honey- 128 IXSECT ARCHITECTURE. bee. There are numerous species of social bees, which, while they diifer in many circumstances, agree in the prac- tice of storing up honey, in the same way as we have numerous species of the mason-bee and of the humble-bee. Of the latter Mr. Stephens enumerates no less than forty- two species indigenous to Britain. ( 129 ) CHAPTER YII. CARPENTRY OF TREE-HOPRERS AND SAW-FLIES. The operations of an insect in boring into a leaf or a bud to form a lodgment for its eggs appear very simple. The tools, however, by which these effects are performed are very complicated and curious. In the case of gall-flies (Ci/m'ps), the operation itself is not so remarkable as its subsequent chemical effects. These effects are so different from any others that may be classed under the head of Insect Architectu]e, that we shall reserve them for the latter part of this volume ; although, with reference to the use of galls, the protection of eggs and larvae, they ought to find a place here. AVe shall, however, at present confine ourselves to those which simply excavate a nest, without producing a tumour. The first of these insects which we shall mention is celebrated for its song, by the ancient Greek poets, under the name of Tettix. The Eomans called it Cicada, which we sometimes, but erroneously, translate " grasshopper;" for the grasshoppers belong to an entirely different order of insects. We shall, therefore, take the liberty of calling the Cicadse Treehoppers, to which the cuckoo-spit insect {^Telti- gonia spumaria, Oliv.) is allied ; but there is only one of the true Cicadas hitherto ascertained to be British, namely, the Cicada hcematodes (Linn.), which Avas discovered in the New Forest, Hampshire, by Mr. Daniel Bydder. M. Reaumur was exceedingly anxious to study the eco- nomy of those insects ; but they not being indigenous in the neighbourhood of Paris, he commissioned his friends to send him some from more southern latitudes, and he pro- cured in this way specimens not only from the South of France and from Italy, but also from Egypt. From these specimens he has given the best account of them yet K 130 INSECT ARCHITECTURE. published ; for tliough, as lie tells us, he had never had the pleasure of seeing one of them alive, the more interesting parts of their structure can be studied as well in dead as in living specimens. We ourselves possess several specimens from New Holland, upon which we have verified some of the more interesting observations of Reaumur. Virgil tells us, that in his time " the cicada burst the very shrubs with their querulous music ;"* but we may well suppose that he was altogether unacquainted with the singular instrument by means of which they can, not poet- ically, but actually, cut grooves in the branches they select for depositing their eggs. It is the male, as in the case of birds, which fills the woods with his song; while the female, though mute, is no less interesting to the naturalist on account of her curious ovipositor. This instrument, like all those with which insects are furnished by nature for cutting, notching, or piercing, is composed of a horny substance, and is also considerably larger than the size of the tree-hopper would proportionally indicate. It can on this account be partially examined without a microscope, being, in some of the larger species, no less than five linesf in length. The ovipositor, or auger (tariere), as Eeaumur calls it, is lodged in a sheath which lies in a groove of the terminat- ing ring of the belly. It requires only a very slight pres- sure to cause the instrument to protrude from its sheath, when it appears to the naked eye to be of equal thickness thi'oughout, except at the point, where it is somewhat enlarged and angular, and on both sides finely indented with teeth. A more minute examination of the sheath demonstrates that it is composed of two horny pieces slightly curved, and ending in the form of an elongated spoon, the concave part of which is adapted to receive the convex end of the ovipositor. When the protruded instrument is further examined with a microscope, the denticulations, nine in number on each side, appear strong, and arranged with great sym- * "Cantu quenilae rumpent arbusta cicadte." Georg. iii. 328. t A line is about the twelfth i^art of an inch. TREE-HOPPERS. 131 metry, increasing in fineness towards the point, where there are three or four very small ones, beside the nine that are more obvious. The magnifier also shows that the instrument itself, which appeared simple to the naked eye, is, in fact, composed of three difi"erent pieces, two exterior armed with the teeth before mentioned, denomi- nated by Eeaumur files (limes), and another pointed like a lancet, and not denticulated. The denticulated pieces, moreover, are capable of being moved forwards and back - wards, while the centre one remains stationary ; and as this motion is effected by pressing a pin or the blade of a knife, over the muscles on either side at the origin of the ovipositor, it may be presumed that those muscles are destined for producing similar movements when the insect requires them. By means of a finely-pointed pin carefully introduced between the pieces, and pushed very gently downwards, they may be, with no great difiiculty, separated in their whole extent. The contrivance by which those three pieces are held united, while at the same time the two files can be easily put in motion, is similar to some of our own mechanical inventions, with this difference, that no human workman could construct an instrument of this description so small, fine, exquisitely polished, and fitting so exactly. We should have been apt to form the grooves in the central piece, whereas they are scooped out in the handles of Ihe files, and play upon two projecting ridges in the central piece, by which means this is rendered stronger. M, Reaumur discovered tliat the best manner of showing the play of this extraordinary instrument is to cut it off with a pair of scissors near its origin, and then, taking it between the thumb and the finger at the point of section, work it gently to put the files in motion. Beside the muscles necessary for the movement of the files, the handle of each is terminated by a curve of the same hard horny substance as itself, which not only fur- nishes the muscles with a sort of lever, but serves to press, as with a spring, the tv/o files close to the central piece, as is shown in the lower fio'ure. o 132 INSECT ARCHITECTUKE. M. Pontedera, who studied the economy of the tree- hoppers with some care, was anxious to see the insect Ovipositcrs, with tiles, of Tree-hopper, uiagnilied. itself make use of the ovipositor in forming grooves in wood, but found that it was so shy and easily alarmed, that it took to flight whenever he approached ; a circumstance of which Reaumur takes advantage, to soothe his regret that the insects were not indigenous in his neighbourhood. But of their workmanship, when completed, he had several specimens sent to him from Provence and Langnedoc by the Marquis de Caumont. The gall-flies, when about to deposit their eggs, select growing plants and trees ; but the tree-hoppers, on the contrary, make choice of dead, dried branches, for the mother seems to be aware that moisture would injure her progeny. The branch, commonly a small one, in which . -^ .^>. -^-^ >X k^_._^ Excavations for eggs of Tree-hopper, with the chip-lids raised. eggs have been deposited, may be recognised by being covered with little oblong elevations caused by small SAW-FLIES. 133 splinters of the wood, detached at one end, but left fixed at the other by the insect. These elevations are for the most part in a line, rarely in a double line, nearly at equal distances from each other, and form a lid to a cavity in the wood about four lines in length, containing from four to ten eggs. It is to be remarked, that the insect always selects a branch of such dimensions, that it can get at the pith, not because the pith is more easily bored, for it does not penetrate into it at all, but to form a warm and safe bed for the eggs. M. Pontedera says, that when the eggs have been deposited, the insect closes the mouth of the hole with a gum capable of protecting them from the weather ; but M. Eeaumur thinks this only a fancy, as, out of a great number which he examined, he could discover nothing of the kind. Neither is such a pro- tection wanted ; for the woody splinters above mentioned furnish a very good covering. The grubs hatched from these eggs (of which, M. Pon- tedera says, one female will deposit from five to seven hundred) issue from the same holes through which the eggs have been introduced, and betake themselves to the ground to feed on the roots of plants. They are not transformed into chrysalides, but into active nymphs, remarkable for their fore limbs, which are thick, strong, and furnished with prongs for digging ; and when we are told, by Dr. Le Fevre, that they make their way easily into hard stiff clay, to the depth of two or three feet, we perceive how necessary to them such a conformation must be. Saw-Flies . An instrument for cutting grooves in wood, still more ingeniously contrived than that of the tree-hopper, was first observed by Vallisnieri, an eminent Italian naturalist, in a four-winged fly, most appropriately denominated by M. Eeaumur the saytyfly (Tenthredo), of which many sorts are indigenous to Great Britain. The grubs from which those flies originate are indeed but too well known, as the}' frequently strip our rose, gooseberry, raspberry, and red 134 INSECT ARCHITECTURE. currant trees of their leaves, and are no less destructive to birch, alder, and willows ; while turnips and wheat suffer still more seriously by their ravages. These grubs may readily be distinguished from the caterpillars of moths and butterflies by having from sixteen to twenty- eight feet, by which they usually hang to the leaf they feed on, while they coil up the hinder part of their body in a spiral ring. The perfect flies are distinguished by four transparent wings ; and some of the most common have a flat body of a yellow or orange colour, while the head and shoulders are black. In order to see the ovipositor, to which we shall for the present turn our chief attention, a female saw-fly must be taken, and her belly gently pressed, when a narrow slit will be observed to open at some distance from the apex, and a short, pointed, and somewhat curved body, of a brown colour and horny substance, will be protruded. o. Ovipositor of Saw-fly, prutnuled lioni its slieath, magnified. The curved plates which form the sides of the slit, are the termination of the sheath, in which the instrument lies concealed till it is wanted by the insect. The appear- ance of this instrument, however, and its singular struc- ture, cannot be well understood without the aid of a micro- scope. The instrument thus brought into view is a very finely- contrived saw, made of a horny substance, and adapted for penetrating branches and other parts of plants where the eggs are to be deposited. The ovipositor-saw of the insect is much more complicated than any of those em- ployed by our carpenters. The teeth of our saws are formed in a line, but in such a manner as to cut in two SAW-FLIES. 135 lines parallel to, and at a small distance from, each otlier. This is effected by slightly bending the points of the alternate teeth right and left, so that one-half of the whole teeth stand a little to the right, and the other half a little to the left. The distance of the two parallel lines thus formed is called the course of the saw, and it is only the portion of wood which lies in the coiTi'se that is cut into saw-dust by the action of the instrument. It will follow, that in proportion to the thinness of a saw there will be the less destruction of wood which may be sawed. When cabinet-makers have to divide valuable wood into very thin leaves, they accordingly employ saws with a narrow course ; while sawyers who cut planks, use one with a broad course. The ovipositor-saw being extremely fine, does not require the teeth to diverge much ; but from the manner in which they operate, it is requisite that they should not stand, like those of our saws, in a straight line. Ovipositor-saw of Saw-fly, witli rasps shown in the cross lines. The greater portion of the edge of th^ instrument, on the contrary, is towards the point somewhat concave, similar to a scythe, while towards the base it becomes a little convex, the whole edge being nearly the shape of an Italic/. The ovipositor-saw of the fly is put in motion in the same way as a carpenter's hand-saw, supposing the tendons 136 INSECT ARCHITECTURE. attached to its base to form the handle, and the muscles which put it in motion to be the hand of the carpenter. But the carpenter can only work one saw at a time, whereas each of these flies is furnished with two, equal and similar, which it works at the same time — one being advanced and the other retracted alternately. The secret, indeed, of working more saws than one at once is not un- known to our mechanics ; for two or three are sometimes fixed in the same frame. These, however, not only all move upwards and downwards simultaneously, but cut the wood in different places ; while the two saws of the ovi- positor work in the same cut, and consequently, though the teeth are extremely fine, the effect is similar to a saw with a wide set. It is important, seeing that the ovipositor-saws are so fine, that they be not bent or separated while in opera- tion — and this, also, nature has provided for, by lodging the backs of the saws in a groove, formed by two mem- braneous plates, similar to the structure of a clasp-knife. These plates are thickest at the base, becomiijg gradually thinner as they approach the point which the form of the saws requires. According to Vallisnieri, it is not the only use of this apparatus to form a back for the saws, he having discovered, between the component membranes, two canals, which he supposes are employed to conduct the eggs of the insect into the grooves which it has hollowed out for them.* The teeth of a carpenter's saw, it may be remarked, are simple, whereas the teeth of the ovipositor-saw are themselves denticulated Avith fine teeth. The latter, also, combines at the same time the properties of a saw and of a rasp or file. So far as we are aware, these two pro23er- ties have never been combined in any of the tools of our carpenters. The rasping part of the ovipositor, however, is not constructed like our rasps, with short teeth thickly studded together, but has teeth almost as long as those of the saw, and placed contiguous to them, on the back of the instrument, resembling in their form and setting the '* Eeaumiu-, Mem. des Insectes, v. p. 3. SAW-FLIES. 137 teeth of a comb, as may be seen in the figure. Of course, such observations are conducted with the aid of a micro- scope. Portion of Saw-fly's comb-toothed rasi), and saw. When a female saw-fly has selected the branch of a rose-tree, or any other, in which to deposit her eggs, she may be seen bending .the end of her belly inwards, in form of a crescent, and protruding her saw, at the same time, to penetrate the bark or wood. She maintains this recurved position so long as she works in deepening the groove; but when she has attained the depth required, she unbends her body into a straight line, and in this position works upon the place lengthways, by applying the saw more horizontally. When she has rendered the groove as large as she wishes, the motion of the tendons ceases, and an egg is placed in the cavity. The saw is then withdrawn into the sheath for about two-thirds of its length, and at the same moment a sort of frothy liquid, similar to a lather made with soap, is dropped over the egg, either for the purpose of gluing it in its place or sheathing it from the action of the juices of the tree. She proceeds in the same manner in sawing out a second groove, and so on in succession, till she has deposited all her eggs, sometimes to the number of twenty-four. The grooves are usually placed in a line, at a small distance from one another, on the same branch ; but sometimes the mother-fly shifts to another, or to a different part of the branch, when she is either scared or finds it unsuitable. She commonly, also, takes more than one day to the work, notwithstanding the superiority of her tools. Eeaumur has seen a saw-fly make six grooves in succession, which occu- pied her about ten hours and a half. The grooves, when finished, have externally little 138 INSECT ARCHITECTURE. elevation above the level of the bark, appearing like the puncture of a lancet in the human skin ; but in the course of a day or two the part becomes first brown and then black, while it also becomes more and more elevated. This increased elevation is not owing to the growth of the bark, the fibres of which, indeed, have been destroyed by the ovipositor-saw, but to the actual growth of the egg ; for when a new-laid egg of the saw-fly is compared with one which has been several days enclosed in the groove, the latter will be found to be very considerably the larger. This gi'owth of the egg is contrary to the analogy observable in the eggs of birds, and even of most other insects ; but it has its advantages. As it continues to increase, it raises the bark more and more, and conse- quently widens, at the same time, the slit at the entrance ; so that, when the grub is hatched, it finds a passage ready for its exit. The mother-fly seems to be aware of this growth of her eggs, for she takes care to deposit ihem at such distances as may prevent their disturbing one another by their development. Another species of saw-fly, with a yellow body and deep violet-coloured wings, which also selects the rose- tree, deposits her eggs in a diff'erent manner. Instead of making a groove for each egg, like the preceding, she forms a large single groove, sufficient for about two dozen eggs. These eggs are all arranged in pairs, forming two straight lines parallel to the sides of the branch. The eggs, however, though thus deposited in a common groove, are carefully kept each in its place ; for a ridge of the Nest of eggs of Saw-fly, in rose tree. wood is left to prevent those on the right from touching those on the left— and not only so, but between each egg SAW-FLIES. 139 of a row a thin partition of wood is left, forming a shallow cell. The edges of this groove, it will be obvious, must be farther apart than those which only contain a single egg, and, in fact, the whole is open to inspection ; but the eggs are kept from falling out, both by the frothy glue before mentioned, and by the walls of the cells containing Ihem. They were observed also, by Vallisnieri, to increase in size like the preceding. ( 140 ) CHAPTER VIII. LEAF-ROLLIXG CATERPILLAES. The labours of those insect-architects, which we have endeavoured to describe in the preceding pages, have been chiefly those of mothers to form a secure nest for their eggs, and the young hatched from them, during the first stage of their existence. But a much more numerous and not less ingenious class of architects may be found among the newly-hatched insects themselves, who, un- taught by experience, and altogether unassisted by pre- vious example, manifest the most marvellous skill in the construction of tents, houses, galleries, covert-ways, forti- fications, and even cities, not to speak of subterranean caverns and subaqueous apartments, which no human art could rival. The caterpillars, which are familiarly termed leaf-rollers, are perfect hermits. Each lives in a cell, which it begins to construct almost immediately after it is hatched ; and the little structure is at once a house which protects the caterpillar from its enemies, and a store of food for its sub- sistence, while it remains shut up in its prison. But the insect only devours the inner folds. The art which these caterpillars exercise, although called into action but once, perhaps, in their lives, is perfect. They accomplish their purpose with a mechanical skill, which is remarkable for its simplicity and unerring success. The art of rolling leaves into a secure and immovable cell may not appear very difficult : nor would it be so if the caterpillars had fingers, or any parts which were equivalent to those deli- cate and admirable natural instruments with which man accomplishes his most elaborate works. And yet the human fingers could not roll a rocket-case of paper more regularly than the caterpillar rolls his house of leaves. A leaf is not a very easy substance to roll. In some trees it CATERPILLARS. 141 is very brittle. It has also a natural elasticity, — a disposi- tion to spring back if it be bent, — which is caused by the continuity of its threads, or nervures. This elasticity is speedily overcome by the ingenuity with which the cater- pillar works ; and the leaf is thus retained in its artificial position for many weeks, under every variety of tempera- ture. We will examine, in detail, how these little leaf- rollers accomplish their task. One of the most common as well as the most simple fabrics constructed by caterpillars, may be discovered dur- ing summer on almost every kind of bush and tree. We shall take as examples those which are found on the lilac and on the oak. A small but very pretty chocolate-coloured moth abun- Lilac-tree Moth. (Lozotcenia iZt&ea«a, Stephens?) dant in every garden, but not readily seen, from its fre- quently alighting on the ground, which is so nearly of its own colour, deposits its eggs on the leaves of the currant, the lilac, and of some other trees, appropriating a leaf to each egg. As soon as the caterpillar is hatched. Kestofa Lilac-leaf KoUer. it begins to secure itself from birds and predatory insects 142 INSECT ARCHITECTURE. by rolling up the lilac leaf into the form of a gallery, where it may feed in safety. We have repeatedly seen one of them when just escaped from the egg, and only a few lines long, fix several silk threads from one edge of a leaf to the other, or from the edge to the mid-rib. Then going to the middle of the space, he shortened the threads by bending them with his feet, and consequently pulled the edges of the leaves into a circular form ; and he retained them in that position by gluing down each thread as he shortened it. In their younger state, those cater- Another nest of Lilac-leaf Roller. pillars seldom roll more than a small portion of the leaf ; but, when farther advanced, they unite the two edges together in their whole extent, with the exception of a small opening at one end, by which an exit may be made in case of need. Another species of caterpillar, closely allied to this, rolls up the lilac leaves in a different form, beginning at the end of a leaf, and fixing and pulling its threads till it gets it nearly into the shape of a scroll of parchment. To retain this form more securely, it is not contented, like the former insect, with threads fixed on the inside of the leaf; CATERPILLARS. 143 but has also recourse to a few cables which it weaves on the outside. Another species of moth, allied to the two preceding, is of a pretty green colour, and lays its eggs upon the Small gi-eeu Oak-moth. {Tortrix Viridana.) leaves of the oak. This caterpillar folds them up in a similar manner, but with this difference, that it works on the under surface of the leaf, pulling the edge downwards and backwards, instead of forwards and upwards. This species is very abundant, and may readily be found as soon as the leaves expand. In June, when the perfect Nests of Oak-leaf-rolling Caterpillars. insect has appeared, by beating a branch of an oak, a whole shower of these pretty green moths may be shook into the air. Among the leaf-rolling caterpillars, there is a small 144 IXSECT ARCHITECTURE. dark-brown one, with a black bead and six feet, very common in gardens, on the cnrrant-bnsb, or the leaves of the rose-tree (Lozotcenia Eosana, Stephens). It i's ex- ceedingly destructive to the flower-buds. The eggs are deposited in the summer, and probably also in the autumn or in spring, in little OA^al or circular patches of a green colour. The grub makes its appearance with the first opening of the leaves, of whose striicture in the half- expanded state it takes advantage to construct its summer tent. It is not, Hke some of the other leaf-rollers, con- tented with a single leaf, but weaves together as many as there are in the bud where it may chance to have been hatched, binding their discs so firmly with silk, that all the force of the ascending sap, and the increasing growth of the leaves cannot break through ; a farther expansion is of course prevented. The little inhabitant in the mean- while banquets securely on the partitions of its tent, eating door-ways, from one apartment into another, through wbich it can escape in case of danger or disturb- ance. The leaflets of the rose, it may be remarked, expand in nearly the same manner as a fan, and the operations of this ingenious little insect retain them in the form of a fan nearly shut. Sometimes, however, it is not contented with one bimdle of leaflets, but by means ofi ts silken cords unites all which spring from the same bud into a rain-proof canopy, under the protection of which it can feast on the flower-bud, and prevent it from ever blowing. In the instance of the currant-leaves, the proceedings of the grub are the same ; but it cannot imite the plaits so smoothly as in the case of the rose leaflets, and it re- quires more labour, also, as the nervures, being stiff, demand a greater effort to bend them. When all the exertions of the insect prove unavailing in its endeavours to draw the edges of a leaf together, it bends them in- wards as far as it can, and weaves a close web of silk over the open space between. This is well exemplified in one of the commonest of our leaf-rolling caterpillars, which may be found as early as February on the leaves of the CATERPILLARS. 145 nettle and the white archangel {Lamiam album). It is of a light dii-ty-green colour, spotted with black, and covered with a few hairs. In its yoimg state it confines itself to the bosom of a small leaf, near the insertion of the leaf- stalk, partly bending the edges inwards, and covering in the interval with a silken curtain. As this sort of covering is not sufficient for concealment when the animal advances in growth, it abandons the base of the leaf for the middle, where it doubles up one side in a very secure and ingenious manner. Nest of the Nettle-leaf-rolling Caterpillar. We have watched this little architect begin and finish his tent upon a nettle in our study, the whole operation taking more than half an hour. (J. E.) He began by walking over the plant in all directions, examining the leaves severall}^ as if to ascertain which was best fitted for his purpose by being pliable, and bending with the weight of his body. Having found one to his mind, he placed himself along the mid-rib, to the edge of which he secured himself firmly with the pro-legs of his tail ; then stretching his head to the edge of the leaf, he fixed a series of parallel cables between it and the mid-rib, with another series crossing these at an acute angle. The position in which he worked was most remarkable, for he did not, as might have been suppos^, spin his cables with his face to the leaf, but throwing himself on his back, which was turned towards the leaf, he hung with his whole weight by his first-made cables. This, by drawing them into the form of a curve, shortened them, and consequently pulled the edge of the leaf down towards the mid-rib. The weight of his body was not, however, the only power which he employed ; for, using the terminal 146 INSECT ARCHITECTURE. pro-legs as a point of support, he exerted the whole muscles of his body to shorten his threads, and pull down the edge of the leaf. When he had drawn the threads as tight as he could, he held them till he spun fresh ones of sufficient strength to retain the leaf in the bent position into which he had pulled it. He then left the first series to hang loose while he shortened the fresh-spun ones as before. This process was continued till he had worked down about an inch and a half of the leaf, as much as he deemed sufficient for his habitation. This was the first part of the architec- ture. By the time he had ^worked to the end of the fold, he had brought the edge of the leaf to touch the mid -rib ; but it was only held in this position by a few of the last- spun threads, for all the first-spun ones hung loose within. Apparently aware of this, the insect protruded more than half of its body through the small aperture left at the end, and spun several bundles of threads on the outside pre- cisely similar to those ropes of a tent which extend beyond the canvas, and are i^^gged into the ground. Unwilling to trust the exposure of his whole body on the outside, lest he should be seized by the first sand-wasp (odymrus) or sparrow which might descry him, he now Avithdrew to complete the internal portion of his dwelling, where the threads were hanging loose and disorderly. F-or this purpose he turned his head about, and proceeded precisely as he had done at the beginning of his task, but taking care to spin his new threads so as to leave the loose ones on the outside, and make his apartment smooth and neat. When he again reached the opposite end, he con- sti-ucted there also a similar series of cables on the out- side, and then witlfdrew to give some final touches to the interior. It is said by Kirby and Spence,* that when these leaf- rolling insects find that the larger nervures of the leaves are so strong as to prevent them from bending, they "weaken it by gnawing it here and there half through." A\'e have never observed the circumstance, though we * Introd. vol. i. p. 457. CATERPILLARS. 14' have witnessed the process in some hundreds of instances ; and we doubt the statement, from the careful survey which the insect makes of the capabilities of the leaf before the operation is begun. If she found upon examination that a leaf would not bend, she would reject it, as we have often seen happen, and pass to another. (J. R.) A species of leaf-roller, of the most diminutive size, merits particular mention, although it is not remarkable in colour or figure. It is without hair, of a greenish- white, and has all the vivacity of the other leaf-rollers. Sorrel is the jjlant on which it feeds ; and the manner in which it rolls a portion of the leaf is very ingenious. The structure which it contrives is a sort of conical Leaf-rolling Caterpillars of the Sorrel. pyramid, composed of five or six folds lapped round each other. From the position of this little cone the cater- pillar has other labours to perform, beside that of rolling the leaf. It first cuts across the leaf, its teeth acting as a pair of scissors ; but it does not entirely detach this seg- ment. It rolls it up very gradually, by attaching threads of silk to the plane surface of the leaf, as we have before seen ; and then, having cut in a different direction, sets the cone upright, by weaving other threads, attached to the centre of the roll and the plane of the leaf, upon which it throws the weight of its body. This, it will be readily 148 INSECT ARCHITECTURE. seen, is a somewliat complicated eifort of mechanical skill. It has been minutely described by M. Eeauraur ; but the preceding representation will perhaps make the process clearer than a more detailed account. This caterpillar, like those of which we have already spoken, devours all the interior of the roller. It weaves, also, in the interior, a small and thin cocoon of white silk, the tissue of which is made compact and close. It is then transformed into a chrysalis. The caterpillars of two of our largest and handsomest butterflies, the painted lady {Cynthia carciui, Stephens), and the admirable, or Alderman of the London fl}- fanciers ( Vanessa atalanta), are also leaf-rollers. The first selects the leaves of the great spear-thistle, and sometimes those of the stemless or star-thistle, which might be sripposed rather difficult to bend ; but the caterpillar is four times as large and strong as those which we have been hitherto Nests of the Hesperia malvaj, with Caterpillar, Chrysalis, and Butterflies describing. In some seasons it is plentiful ; in others it is rarely to be met with : but the admirable is seldom CATERPILLARS. 149 scarce in any part of the country ; and by examining the leaves of nettles which appear folded edge to edge, in July and August, the caterpillar may be readily found. Another butterfly {Hesperia malvoe) is met with on drj^ banks where mallows grow, in May, or even earlier, and also in August, but is not indigenous. The caterpillar, which is grey, with a black head, and four sulphur-coloured spots on the neck, folds around it the leaves of the mallow, upon which it feeds. There is nothing, however, pecu- liarly different in its proceedings from those above de- scribed ; but the care with which it selects and rolls up one of the smaller leaves, when it is about to be trans- formed into a chrysalis, is worthy of remark ; it joins it, indeed, so completely round and round, that it has some- what the resemblance of an egg. Within this green cell it lies secure, till the time arrives when it is ready to burst its cerements, and trust to the quickness of its wings for protection against its enemies. Among the nests of caterpillars which roll up parcels of leaves, we know none so well contrived as those which are found upon willows and a species of osier. The long and narrow leaves of these plants are naturally adapted to be adjusted parallel to each other ; for this is the direction which they have at the end of each stalk, when they are not entirely developed. One kind of small smooth cater- pillar {lortrix chhrand), with sixteen feet, the under part of which is brown, and streaked with white, fastens these leaves together, and makes them up into parcels. There is nothing particularly striking in the mechanical manner in which it constructs them. It does precisely what we should do in a similar case : it winds a thread round those leaves which must be kept together, from a little above their termination to a very short distance from their extreme point ; and as it finds the leaves almost constantly lying near each other, it has little difficulty in bringing them together, as is shown in the following cut, a. The prettiest of these parcels are those which are made upon a kind of osier, the borders of whose leaves sometimes form columnar bundles before they become developed. A 150 IXSECT ARCHITECTURE. section of these leaves has the appearance of filigree-work (see b). :Sest of Willow-leaf Roller. A caterpiUar which feeds upon the willow, and whose singular attitudes have obtained for it the trivial name of Ziczac, also constructs for itself an arbour of the leaves, by drawing them together in an ingenious manner. M. Eoesel* has given a tolerable representation of this nest, and of the caterpillar. The caterpillar is found in June ; and the moth (Nofodonta ziczac) from May to July in the following year (see cut, p. 151). Beside those caterpillars which live solitary in the folds of a leaf, there are others which associate, employing their united powers to draw the leaves of the plants they feed upon into a covering for their common protection. Among these we may mention the caterpillar of a small butterfly, * Roesel, cl. ii., Pap. Noctirrn., tab. xx. fig. 1, 2, 3, 4, 5, 6. CATERPILLARS. 151 the plantain or Glanville fritillary {Melitea cinxia), which is very scarce in this country. Although a colony of these caterpillars is not numerous, seldom amounting to a hundred individuals, the place Ziczac Caterpillar and Nest. which they have selected is not hard to discover. Their abode may be seen in the meadow in form of a tuft of herbage covered with a white web, which may readily be mistaken, at first view, for that of a spider, but closer in- spection soon corrects this notion. It is, in fact, a sort of common tent, in which the whole brood lives, eats, and undergoes the usual transformations. The shape of this tent, for the most part, approaches the pyramidal, though that depends much upon the natural growth of the herbage which composes it. The interior is divided into compart- ments fonned by the union of several small tents, as it were, to which others have been from time to time added according to the necessities of the community. 152 INSECT ARCHITECTURE. When they have devoured all the leaves, or at least those which are most tender and succulent, they abandon their first camp, and construct another contiguous to it under a tuft of fresh leaves. Several of these encamp- ments may sometimes be seen within the distance of a foot or two, when they can find plantain {Plantago lanceolata) fit for their purpose ; but though they prefer this plant, they content themselves with grass if it is not to be pro- cured. When they are about to cast their skins, but particu- larly wlien they perceive the approach of winter, they construct a more durable apartment in the interior of their principal tent. The ordinary web is thin and semi-trans- parent, permitting the leaves to be seen through it; but their winter canvas, if we may call it so, is thick, strong, and quite opaque, forming a soi't of circular hall without any partition, where the whole community lie coiled up and huddled together. Early in spring they issue forth in search of fresh food, and again construct tents to protect them from cold and rain, and from the mid-day sun. M. Reaumur found upon trial, that it was not only the caterpillars hatched from the eggs of the same mother which would unite in constructing the common tent ; for different broods, when put together, worked in the same social and harmonious manner. We ourselves ascertained, during the present summer (1829), that this principle of sociality is not confined to the same species, nor even to the same genus. The experiment which we tried was to confine two broods of different species to the same branch, by placing it in a glass of water to prevent their escape. The caterpillars which we experimented on were several broods of the brown-tail moth (^Porthesia aurijiaa), and the lackey (Clisiocampa- neustria). These we found to work with as much industry and harmony in constructing the common tent as if they had been at liberty on their native trees ; and when the lackej^s encountered the browTi-tails they manifested no alarm nor uneasiness, but passed over the backs of one another, as if they had made CATERPILLARS. 153 only a portion of tlie branch. In none of their operations did they seem to be subject to any discipline, each indi- vidual appearing to work, in perfecting the structure, from individual instinct, in the same manner as was remarked by M. Huber, in the case of the hive-bees.* In making such experiments, it is obvious that the species of cater- pillars experimented with must feed upon the same sort of plant. (J. E.) The design of the caterpillars in rolling up the leaves is not only to conceal themselves from birds and predatory insects, but also to protect themselves from the cuckoo- flies, which lie in wait in every quarter to deposit their eggs in their bodies, that their progeny may devour them. Their mode of concealment, however, though it appear to be cunningly contrived and skilfully executed, is not always successful, their enemies often discovering their hiding-place. We happened to see a remarkable instance of this last summer (1828), in the case of one of the lilac caterpillar which had changed into a chrysalis within the closely-folded leaf. A small ichneumon, aware, it should seem, of the very spot where the chrysalis lay within this leaf, was seen boring through it with her ovipositor, and, introducing her eggs through the punctures thus made into the body of the dormant insect. We allowed her to lay all her eggs, about six in number, and then put the leaf under an inverted glass. In a few days the eggs of the cuckoo-fly were hatched, the grubs devoured the lilac chrj^salis, and finally changed into pupae in a case of yellow silk, and into perfect insects like their parent. (J. E.) * See p. 100. ( 154 ) CHAPTER IX. Insects forming Habitations of detached Leaves. The habitations of the insects which we have jnst described consist of growing leaves, bent, rolled, or pressed together, and fixed in their positions by silken threads. But there are other habitations of a similar kind which are con- structed by cutting out and detaching a whole leaf, or a portion of a leaf. We have already seen how dexterously the upholsterer-bees cut out small parts of leaves and petals with their mandibles, and fit them into their cells. Some of the caterpillars do not exhibit quite so much neatness and elegance as the leaf-cu»tting bees, though their struc- tures answer all the purposes intended; but there are others, as we shall presently see, that far excel the bees, at least in the delicate minutiae of their workmanship. We shall first advert to those structures which are the most simple. Not far from Longchamps, in a road through the Bois de Boulogne, is a large marsh, which M. Eeaumur never observed to be in a dry state even during summer. This marsh is surrounded with very lofty oaks, and abounds with pondweed, the water-plant named by botanists pota- mogeton. The shining leaves of this plant, which are as large as those of the laurel or orange-tree, but thicker and more fleshy, are spread upon the surface of the water. Having pulled up several of these about the middle of June, M. Reaumur observed, beneath one of the first which he examined, an elevation of an oval shape, which was formed out of a leaf of the same plant. He carefully examined it, and discovered that threads of silk were attached to this elevation. Breaking the threads, he raised up one of the ends, and saw a cavity, in which a caterpillar POx^DWEED TENT-MAKER. 155 (^Hydrocampa potamoget(i) was lodged. An indefatigable ob- server, such as M. Eeaumur, would naturally follow up this discovery ; and he has accordingly given us a memoir of the pond weed tent-maker, distinguished by his usual minute accuracy. In order to make a new habitation, the caterpillar fastens itself on the under side of a leaf of the Potamogeton. With its mandibles it pierces some part of this leaf, and afterwards gradually gnaws a curved line, marking the form of the piece which it wishes to detach. "When the caterpillar has cut off, as from a piece of cloth, a patch of leaf of the size and shape suited to its purpose, it is pro- vided with half of the materials requisite for making a tent. It takes hold of this piece by its mandibles, and conveys it to the situation on the under side of its own or another leaf, whichever is found most approprite. It is there dis- posed in such a manner that the under part of the patch — the side which was the under part of the entire leaf — is turned towards the under part of the new leaf, so that the inner walls of the cell or tent are always made by the under part of two portions of leaf. The leaves of the potamogeton are a little concave on the under side ; and thus the caterpillar produces a hollow cell, though the rims are united. The caterpillar secures the leaf in its position by threads of white silk. It then weaves in the cavity a cocoon, which is somewhat thin, but of very close tissue. There it shuts itself up, to appear again only in the form of the perfect insect, and is soon transformed into a chrysalis. In this cocoon of silk no point touches the water ; whilst the tent of leaves, lined with silk, has been constructed underneath the water. This fact proves that the cater- pillar has a particular art by which it re23els the Avater from between the leaves. When the caterpillar, which has thus conveyed and disposed a patch of leaf against another leaf, is not ready to be transformed into a chrysalis, it applies itself to make a tent or habitation which it may carry everywhere about with it. It begins by slightly fixing the piece against 156 INSECT ARCHITECTURE. the perfect leaf, leaving intervals all round, between the piece and leaf, at which it may project its head. The piece which it has fixed serves as a model for cutting out a similar piece in the other leaf. The caterpillar puts them accurately together, except at one end of the oval, where an opening is left for the insect to project its head through. When the caterpillar is inclined to change its situation, it draws itself forward by means of its scaly limbs, riveted upon the leaf. The membranous limbs, which are riveted against the inner sides of the tent, oblige it to follow the anterior part of the body, as it advances. The caterpillar, also, puts its head out of the tent every time it desires to eat. There is found on the common chickweed (Stellaria media), towards the ends of July, a middle-sized smooth green caterpillar, having three brown spots bordered with white on the back, and six legs and ten pro-legs, whose architecture is worthy of observation. When it is about to go into chrysalis, towards the beginning of August, it gnaws oif, one by one, a number of the leaves and smaller twigs of the chickweed, and adjusts them into an oval cocoon, somewhat rough and unfinished externally, but smooth, uniform, and finely tapestried with white silk within. Here it undergoes its transformation securely, and, when the period of its pupa trance has expired in the following July, it makes its exit in the form of a yellowish moth, with several brown spots above, and a brown band on each of ils four wings below. It is also furnished with a sort of tail. On the cypress-spurge (EaphorUa cr/parissias), a native woodland plant, but not of very common occurrence, may be found, towards the end of October, a caterpillar of a middle size, sparely tufted with hair, and striped with black, white, red, and brown. The leaves of the plant, which are in the form of short narrow blades of grass, are made choice of by the caterpillar to construct its cocoon, which it does with great neatness and regularity, the end of each leaf, after it has been detached from the plant, being fixed to the stem, and the other leaves placed parallel, CYPRESS-SPURGE CATERPILLAR. 157 as they are successively added. The other ends of all these are bent inwards, so as to form a uniformly rounded oblong figure, somewhat larger at one end than at the other. Cypress-Spurge Ca.ieTi>i\\a,T—<,Acronycta Euphrasia ?}— with a Cocoon, on a branch. A caterpillar which builds a very similar cocoon to the last-mentioned may be found upon a more common plant — the yellow snap-dragon or toad-flax {Antirrhinum linaria) — which is to be seen in almost every hedge. It is some- what shaped like a leech, is of a middle size, and the pre- vailing colour pearl-grey, but striped with yellow and black. It spins up about the beginning of September, forming the outer coating of pieces of detached leaves of the plant, and sometimes of whole leaves placed longitu- dinally, the whole disposed with great symmetry and neat- ness. The moth appears in the following June. It is worthy of remark, as one of the most striking instances of instinctive foresight, that the caterpillars which build structures of this substantial description are destined to lie much longer in their chrysalis trance than those which spin merely a flimsy web of silk. For the most part, indeed, the latter undergo their final trans- formation in a few weeks ; while the former continue en- tranced the larger portion of a year, appearing in the per- fect state the summer after their architectural labours have been completed. (J. E.) This is a remarkable example of the instinct which leads these little creatures to act as if under the dictates of prudence, and with a perfect know- 158 INSECT ARCHITECTURE. ledge of the time, be it long or skort, which will elapse before the last change of the pupa takes place. That the caterpillar, while weaving its cocoon and preparing to assume the pupa state, exercises any reflective faculties, or is aware of what is about to occur relative to its own self, we cannot admit. It enters upon a work of which it has had no previous experience, and which is per- formed, as far as contingencies allow, in the same manner by every caterpillar of the same species. Its labours, its mode of carrying them on, and the very time in which they are to be commenced, are all pre-appointed ; and an instinctive impulse urges and guides; and with this instinct its organic endowments are in precise harmony ; nor does instinct ever impel to labours for which an animal is not provided. "The same wisdom," saj^s Bonnet, " which has constructed and arranged with so much art the various organs of animals, and has made them concur towards one determined end, has also pro- vided that the different operations which are the natural results of the economy of the animal should concur to- wards the same end. The creature is directed towards his object by an invisible hand ; he executes with pre- cision, and by one effort, those works which we so much admire ; he appears to act as if he reasoned, to return to his labour at the proper time, to change his scheme in case of need. But in all this he only obeys the secret influence which drives him on. He is but an instrument which cannot judge of each action, but is wound up by that adorable Intelligence, which has traced out for every insect its proper labours, as he. has traced the orbit of each planet. When, therefore, I see an insect working at the construction of a nest, or a cocoon, I am impressed with respect, because it seems to me that I am at a spectacle where the Supreme Artist is hid behind the curtain."* There is a small sort of caterpillar which may be found on old walls, feeding upon minute mosses and lichens, * Contemplation de la Xutui-e, part xv. chap. 38. MOSS-BUILDING CATERPILLAR. 159 the proceedings of which are well worthy of attention. They are similar, in appearance and size, to the cater- pillar of the small cabbage-butterly (Pontia rapce), and are smooth and bluish. The material which they use in building their cocoons is composed of the leaves and branchlets of green moss, which they cut into suitable pieces, detaching at the same time along with them a portion of the earth in which they grow. They arrange these upon the walls of their building, with the moss on the outside, and the earth -on the inside, making a sort of vault of the tiny bits of green moss turf, dug from the surface of the wall. So neatly, also, are the several pieces joined, that the whole might well be supposed to be a patch of moss which had grown in form of an oval tuft, a little more elevated than the rest growing on the wall. When these caterpillars are shut up in a box with some moss, without earth, they construct with it cells in form of a hollow ball, very prettily plaited and interwoven. Moss-Cell of small Caterpillar (BryojMla pei-la ?) In May last (1829), we found on the walls of Green- wich Park a great number of caterpillars, whose manners bore some resemblance to those of the grub described by M. Reaumur. (J. E.) They were of middle size, with a dull orange stripe along the back ; the head and sides of the body black, and the belly greenish. Their abodes were constructed with ingenuity and care. A caterpillar of this sort appears to choose either a part where the mortar contains a cavity, or it digs one suited to its design. Over the opening of the hollow in the mortar it builds an arched wall, so as to form a chamber considerably larger than is usual with other architect caterpillars. It 160 INSECT ARCHITECTURE. selects grains of mortar, brick, or lichen, fixing tliem, by means of silk, firmly into the structure. As some of these vaulted walls were from an inch to an inch and a half long, and about a third of an inch wide and deep, it may be well imagined that it would require no little industry and labour to complete the work. Yet it does not demand more than a few hours for the insect to raise it from the foundation. Like all other insect architects, this cater- pillar uses its own body for a measuring-rule, and partly for a mould, or rather a block or centre to shape the walls by, curving itself round and round concentrically with the arch which it is building. We afterwards found one of these caterpillars, which had dug a cell in one of the softest of the bricks, cover- ing itself on the outside with an arched wall of brick-dust, cemented with silk. As this brick was of a bright-red colour, we were thereby able to ascertain that there was not a particle of lichen employed in the structure. The neatness mentioned by Eeaumur, as remarkable in his moss-building caterpillars, is equally observable in that which we have just described ; for, on looking at the sur- face of the wall, it would be impossible for a person unac- quainted with those structures to detect where they were placed, as they are usuall}^, on the outside, level with the adjoining brick-work ; and it is only when they are opened by the entomologist, that the little architect is perceived lying snug in his chamber. If a portion of the wall be thus broken down, the caterpillar immediately commences repair- ing the breach, by piecing in bits of mortar and fragments of lichen, till we can scarcely distinguish the new portion from the old. ( 1«1 ) CHAPTER X. Caddis-Worms and Carpenter-Caterpillars. There is a very interesting class of grubs which live nnder water, where they construct for themselves move- able tents of various materials as their habits direct them, or as the substances they require can be conveniently procured. Among the materials used by these singular grubs, well-known to fishermen by the name of caddis- worms^ and to naturalists as the larvoe of the four-winged flies in the order Trkluoptera of Kirby and Spence, we may mention sand, stones, shells, wood, and leaves, which are skilfully joined and strongly cemented. One of these grubs forms a pretty case of leaves glued together longi- tudinally, but leaving an aperture sufficiently large for the inhabitant to put out its head and shoulders when it Leaf Nest of Caddis- Worm. wishes to look about for food. Another employs pieces of reed cut into convenient lengths, or of grass, straw, wood, &c., carefully joining and cementing each piece to its fellow as the work proceeds ; and he frequently finishes llced Xest of Caddis-Worm.- the whole by adding a broad piece longer than the rest to shade his door-way over-head, so that he may not be seen from above. A more laborious structure is reared by the grub of a beautiful caddis-fly {Phryganea), which weaves together a group of the leaves of aquatic plants 62 IXSECT ARCHITECTURE. into a roundish ball, and in tlie interior of this forms a cell for its abode. The following figure from Eoesel will give a more precise notion of this stnicture than a lengthened description. Another of these aquatic architects makes choice of the tiny shells of young fresh-water mussels and snails (Planorbis), to form a moveable grotto; and as these little shells are for the most part inhal:>ited, he keeps the Shell Nests of Caddis- "VVonns. poor animals close prisoners, and drags them without mercy along with him. These grotto-building grubs are by no means uncommon in ponds ; and in chalk districts such as the country about Woolwich and Gravesend, they are very abimdant. One of the most surprising instances of their skill occurs in the structures of which small stones are the principal material. The problem is to make a tube about the wddth of the hollow of a wheat-straw or a crow-quill, and equally smooth and uniform. Now the materials being small CADDIS-WORMS. 163 stones full of angles and irregularities, the difficulty of performing this problem will appear to be considerable, if not insurmountable : yet the little architects, by patiently examining their stones and turning them round on every side, never fail to accomplish their plans. This, however, stone Nest of Caddis- Worm. is only part of the problem, which is complicated with another condition, and which we have not found recorded by former observers, namely, that the under-surface shall be flat and smooth, without any projecting angles which might impede its progress when dragged along the bottom of the rivulet where it resides. The selection of the stones, indeed, may be accounted for, fi-om this species living in streams where, but for the weight of its house, it would to a certainty be swept away. For this purpose, it is probable that the grub makes choice of larger stones than it might otherwise want ; and therefore also it is that we frequently find a case composed of very small stones and sand, to which, when nearly finished, a large stone is Sand Nest balanced with a Stone. added by way of ballast. In other instances, when the materials are found to possess too great specific gravity, a bit of light wood, or a hollow straw, is added to buoy up the case. Nest ot Caddis Worm balanced with Straws. It is worthy of remark, that the cement, used in all these cases, is superior to pozzolana * in standing water, in which it is indissoluble. The grubs themselves are also admirably adapted for their mode of life, the portion * A cement prepared of volcanic earth, or lava. 164 INSECT ARCHITECTURE. of their bodies which is always enclosed in the case, being soft like a meal-worm, or garden-caterpillar, while the head and shoulders, which are for the most part projected beyond the door- way in search of food, are firm, hard, and consequently less liable to injuiy than the protected portion, should it chance to be exposed. We have repeatedly tried experiments with the inha- bitants of those aquatic tents, to ascertain their mode of building. We have deprived them of their little houses, and furnished them with materials for constructing new ones, watching their proceedings from their laying the first stone or shell of the stnicture. They work at the commencement in a very clumsy manner, attaching a great number of chips to whatever materials may be within their reach with loose threads of silk, and many of these they never use at all in their perfect building. They act, indeed, much like an unskilful workman trying his hand before committing himself upon an intended work of diffi- cult execution. Their main intention is, however, to have abundance of materials within reach : for after their dwelling is fairly begun, they shut themselves up in it, and do not again protrude more than half of their body to procure materials ; and even when they have dragged a stone, a shell, or a chip of reed within building reach, they have often to reject it as unfit. (J. R.) Carpenter-Caterpillars. Insects, though sometimes actuated by an instinct ap- parently blind, unintelligent, or unknown to themselves,- manifest in other instances a remarkable adaptation of means to ends. We have it in our power to exemplify this in a striking manner by the proceedings of the cater- pillai' of a goat-moth (Cossus Ugniperdd) which we kept till it underwent its final change. This caterpillar, which abounds in Kent and many other parts of the island, feeds on the wood of willows, oaks, poplars, and other trees, in which it eats extensive galleries; but it is not contented w^ith the protection GOAT-MOTH. 165 afforded by these galleries during the colder months of winter, before the arrival of which it scoops out a hollow in the tree, if it do not find one ready prepared, sufficiently Caterpillar of Goat-Moth in a Willow Tree. large to contain its body in a bent or somewhat coiled-up position. On sawing off" a portion of an old poplar in the winter of 1827, we found such a cell with a caterpillar coiled up in it. winter Nest of the Goat-Caterpillar It had not, however, been contented with the bare walls of the retreat which it had hewn out of the tree, for it had lined it with a fabric as thick as coarse broadcloth, and equally warm, composed of the raspings of the wood scooped out of the cell, united with the strong silk which every species of caterpillar can spin. In this snug retreat 166 INSECT ARCHITECTURE. our caterpillar, if it had not been disturbed, would have spent the winter without eating ; but upon being removed into a warm room and placed under a glass along with some pieces of wood, which it might eat if so inclined, it was roused for a time from its dormant state, and began to move about. It was not long, however, in constructing a new cell for itself, no less ingenious than the former. It either could not gnaw into the fir plank, where it was now placed with a glass above it, or it did not choose to do so ; for it left it untouched, and made it the basis of the edifice it began to construct. It formed, in fact, a coveiing for itself precisely like the one from which we had dis- lodged it, — composed of raspings of wood detached for the purpose from what had been given it as food, the largest piece of which was employed as a substantial covering and protection for the whole. It remained in this retreat, mo- tionless, and without food, till revived by the warmth of the ensuing spring, when it gnawed its way out, and began to eat voraciously, to make up for its long fast. These caterpillars are three years in arriving at their final change into the winged state; but as the one just mentioned was nearly full grown, it began, in the month of ^lay, to prepare a cell, in which it might undergo its metamorphosis. Whether it had actually improved its skill in architecture by its previous experience we will not undei-take to say, but its second cell was greatly superior to the first. In the fiist there was only one large piece of Xest of Goat-Moth.— Figured from specimen, and raised to show the Pupa. wood employed ; in the second, two f)ieces were placed in such a manner as to support each other, and beneath the PUSS-MOTH. 1G7 angle thus formed an oblong structure was made, composed, as before, of wood-raspings and silk, but much stronger in texture than the winter cell. In a few weeks (four, if we recollect aright) the moth came forth. (J. R) A wood-boring caterpillar, of a species of moth 'much rarer than the preceding (^yEgeria asiliforniis, Stephens), exhibits great ingenuity in constructing a cell for its meta- morphosis. We observed above a dozen of them during this summer (1829) in the trunk of a poplar, one side of which had been stripped of its bark. It was this portion of the trunk which all the caterpillars selected for their final retreat, not one having been observed where the tree was covered with bark. The ingenuity of the little architect consisted in scooping its cell almost to the very surface of the wood, leaving only an exterior covering of unbroken wood, as thin as writing-paper. Previous, there- fore, to the chrysalis making its way through this feeble barrier, it could not have been suspected that an insect was lodged under the smooth wood. We observed more than one of these in the act of breaking through this cover- ing, within which there is, besides, a round moveable lid of a sort of brown wax. (J. R.) Another architect caterpillar, frequently to be met with in July on the leaves of the willow and the poplar, is, in the fly-state, called the puss-moth (^Centra vinula). The caterpillar is produced from brown-coloured shining eggs, about the size of a pin's head, which are deposited — one, two, or more together — on the upper surface of a leaf. In the course of six or eight weeks (during which time it casts its skin thrice) it arrives at its full growth, wdien it Eggs of the Puss-Moth. is about as thick, and nearly as long, as a man's thumb, and begins to prepare- a structure in which the pupa may 168 INSECT ARCHITECTURE. sleep securely during the winter. As we liave, oftener tliaii once, seen this little architect at work, from the foundation till the completion of its edifice, we are thereby enabled to give the details of the process. The puss, it may be remarked, does not depend for pro- tection on the hole of a tree, or the shelter of an overhang- ing branch, but upon the soliditj^ and strength of the fabric which it rears. The material it commonly uses is the bark of the tree upon which the cell is constructed ; but when this cannot be procured, it is contented to employ what- ever analogous materials may be within reach. One which we had sliut up in a box substituted the marble paper it was lined with for bark, which it could not procure.* With silk it first wove a thin web round the edges of the place which it marked out for its edifice ; then it ran several threads in a spare manner from side to side, and from end to end, but very irregularly in point of arrange- * It is justly remarked by Ee'aumur, that when caterpillars are left at liberty among their native plants, it is only by lucky chance they can be observed building their cocoons, because the greater number abandon the plants upon which they have been feeding, to spin up in places at some distance. In order to see their operations, they must be kept in confinement, particularly in boxes with glazed doors, where they may be always under the eye of the natmalist. In such circum- stances, however, we may be ignorant what building materials we ouglit to provide them with for their structures. A red caterpillar, with a few tufts of hair, which Re'aumur found in July feeding upon the flower bunches of the nettle, and refusing to touch the leaves, began in a few days to prepare its cocoon, by knawing the paper lid of the box in which it was placed. This, of course, was a material which it could not have prociu-ed in the fields, but it was the nearest in properties that it could procure ; for, though it had the leaves and stems of nettles, it never used a single fragment of either. AVhen Ee'aumur found that it was likely to gnaw through the paper lid of the box, and might eftect its escape, he furnished it with bits of rumpled paper, fixed to the lid by means of a pin ; and these it chopped down into such pieces as it judged convenient for its structure, which it took a day to complete. The moth appeared four weeks after, of a brownish-black coloiu-, mottled with white, or rather grey, in the manner of lace. Bonnet also mentions more than one instance in which he observed caterpillars making use of i^aper, when they could not prociu'e other materials. PUSS-MOTH. 169 raent ; these were intended for the skeleton or frame-work of the building. When this outline was finished, the next step was to strengthen each thread of silk by adding Kudlments of the Cell of the Puss- Moth. several (sometimes six or eight) parallel ones, -all of which were then glued together into a single thread, by the insect running its mandibles, charged with gluten, along the line. The meshes, or spaces, which were thus widened by the compression of the parallel threads, were immediately filled up with fresh threads, till at length only very small spaces were left. It was in this stage of the operation that the paper came into requisition, small portions of it being gnawed ofi" the box and glued into the meshes. It was not, however, into the meshes only that the bits of paper were inserted; for the whole fabric was in the end thickly studded over with them. In about half a day from the first thread of the frame -work being spun the building was completed. It was at first, however, rather soft, and yielded to slight pressure with the finger ; but as soon as it became thoroughly dry, it was so hard that it could with difficulty be penetrated with the point of a penknife. (J. R.) Cell built by the Larva of the Puss-Moth. A question will here suggest itself to the curious in- quirer, how the moth, which is not, like the caterpillar, furnished with mandibles for gnawing, can find its way 170 INSECT ARCHITECTURE. through so hard a wall. To resolve this question, it is asserted bj recent naturalists (see Kirby and Spence, vol. iii. p. 15), that the moth is furnished with a peculiar acid for dissolving itself a passage. We have a specimen of the case of a puss-moth, in which, notwithstanding its strength, one of the ichneumons had contrived to deposit its eggs. In the beginning of summer, when we expected the moth to appear, and felt anxious to observe the recorded eifects of the acid, we were astonished to find a large orange cuckoo -fly make its escape ; while another, which attempted to follow, stuck by the way and died. On detaching the cell from the' box, we found several others, which had not been able to get out, and had died in their cocoons. (J. R.) Ichneumon {Ophion luteum), figured from the one mentioned. Among the carpenter-grubs may be mentioned that of the purple capricom-beetle {CalUdiiwi violacewii), of which the Rev. Mr. Kirby has given an interesting account in the fifth volume of the ' Linnsean Transactions.' This insect feeds principally on fir timber which has been felled some time without having had the bark stiipped off ; but it is often found on other wood. Though occasionally taken in this kingdom, it is supposed not to have been originally a native. The circumstance of this destructive little animal attacking only such timber as had not been stripped of its bark ought to be attended to by all persons who have any concern in this article ; for the bark is a temptation not only to this, but to various other insects ; and much of the injury done in timber might be prevented, it' the trees were all barked as soon as they were felled. The female is furnished, at the posterior extremity of her body, with a flat retractile tube, which she inserts between the bark and the wood, to the depth of about a quarter of an inch, and there deposits a single egg. By stripping off" the bark, CAPRICORN-BEETLE. 171 it is easy to trace the whole progress of the grub, from the spot where it is hatched, to that where it attains its full size. It first proceeds in a serpentine direction, filling the space which it leaves with its excrement, resembling saw- dust, and so stopping all ingress to enemies from without. When it has arrived at its utmost dimensions, it does not confine itself to one direction, but works in a kind of labyrinth, eating backwards and forwards, which gives the wood under the bark a \qyj irregular surface : by this means its paths are rendered of considerable width. The bed of its paths exhibits, when closely examined, a curious appearance, occasioned by the gnawings of its jaws, which excavate an infinity of little ramified canals. AVhen the insect is about to assume its chrysalis state, it bores down obliquely into the solid wood, to the depth sometimes of three inches, and seldom if ever less than two, forming holes nearly semi-cylindrical, and of exactly the form of the grub which inhabits them. At first sight one would wonder how so small and seemingly so weak an animal could have strength to excavate so deep 'a mine ; but when we examine its jaws, our wonder ceases. These are large, thick, and solid sections of a cone divided longitudinally, which, in the act of chewing, apply to each other the whole of their interior plane surface, so that they grind the insect's food like a pair of millstones. Some of the grubs are hatched in October ; and it is supposed that about the beginning of March they assume their chrysalis state. 'At the place in the bark opposite to the hole from whence they descended into the wood, the perfect insects gnaw their way out, which generally takes place betwixt the middle of May and the middle of June. These insects are supposed only to fly in the night, but during the day they may generally be found resting on the wood from which they were disclosed. The grubs are destitute of feet, pale, folded, somewhat hairy, convex above, and divided into thirteen segments. Their head is large and convex.* ■ It would not be easy to find a more striking example of * Kirby, in ' Linn. Trans.,' vol. v. p. 246, and Introd. ii. 172 IXSECT ARCHITECTURE. ingenuity than occurs in a small caterpillar which may be found in May, on the oak, and is supposed by Kirby and Spence to be that of the Pyralis strigidalis. It is of a whitish-yellow colour, tinged with a shade of carnation, and studded with tufts of red hairs on each segment, and two brown spots behind the head. It has fourteen feet, and the upper part of its body is much flatter than is common in caterpillars. When this ingenious little insect begins to form its cell, it selects a smooth young branch of the oak, near an offgoing of the branchlets whose angle may afford it some protection. It then measures out, with its body for a rule, the space destined for its structure, the basement of which is of a triangular form, with the apex at the lower end. The building itself is composed of small, rectangular, strap-shaped pieces of the outer bark of the branch cut out from the immediate vicinity ; the insect indeed never travels further for materials than the length of its own body. Upon the two longest sides of the tri- Magnifled Cells of Pyralis strlgulalis? a. The walls before they are joined, h. Walls Joined, but not closed at top. c. Side view of structure complete. angular base it builds uniform walls, also of a triangular shape, and both gradually diverging from each other as they increase in height. These are formed with so much OAK-BARK CATERPILLARS. 173 mathematical precision, that they fit exactly when they are afterwards brought into contact. As soon as the little architect has completed these walls, which resemble very much the feathers of an arrow, it proceeds to draw them together in a manner similar to that which the leaf- rolling caterpillars employ in constructing their abodes, by pulling them with silken cords till they bend and converge. Even when the two longest sides are thus joined, there is an opening left at the upper end, which is united in a similar manner. When the whole is finished, it requires close inspection to distinguish it from the branch, being formed of the same materials, and having consequently the same colour and gloss. Concealment, indeed, may be supposed, with some justice, to 'be the final object of the insect in producing this appearance, the same principle being ex- tensively exemplified in numerous other instances. ( 1-^ ) CHAPTEE XI. Earth-mason Caterpillars. Many species of caterpillars are not only skilful in conceal- ing themselves in their cocoons, but also in the concealment of the cocooQ itself; so that even when that is large, as in the instance of the death's-head hawk-moth {Acherontia atropos), it is almost impossible to find it. We allude to the numerous class of caterpillars which, previous to their changing into the pupa state, bury themselves in the earth. This circumstance would not be surprising, were it confined to those which are but too well known in gardens, from their feeding upon and destroying the roots of lettuce, chicory, and other plants, as they pass a considerable por- tion of their lives under ground ; nor is it surprising that those which retire under ground during the day, and come abroad to feed in the night, should form their cocoons where they haA^e been in the habit of concealing themselves. But it is very singular and unexpected, that cateipillars which pass the whole of their life on plants and even on trees, should afterwards bury themselves in the earth. Yet, the fact is, that perhaps a greater number make their cocoons under than above ground, particularly those which are not clothed with hair. Some of those caterpillars, which go into the ground previous to their change, make no cocoon at all, but are contented with a rude masonry of earth as a nest for their pupge : into the details of their operations it will not be so necessary for us to go, as into those which exhibit more ingenuity and care. When one of the latter is dug up it has the appearance of nothing more than a small clod of earth, of a roundish or oblong shape, but, generally, by no means uniform. The interior, however, when it is laid open, always exhibits a cavity, smooth, polished, and EARTH-MASON CATERPILLARS. 175 regular, in which the cocoon or the chrysalis lies secure (Fig. B, p. 176). The polish of the interior is precisely such as might he given to soft earth by moistening and kneading it with great care. But beside this, it is usually lined with a tapestry of silk, more or less thick, though this cannot always be discovered without the aid of a magnify- ing glass. This species of caterpillars, as soon as they have completed their growth, go into the earth, scoop out, as the cossus does in wood, a hollow cell of an oblong form, and line it with pellets of earth, from the size of a grain of sand to that of a pea — united, by silk or gluten, into a fabric more or less compact, according to the species, but all of them fitted for protecting the inhabitant, during its winter sleep, against cold and moisture. Outside view of Xests of Earth-mason Caterpillars. One of the examjjles of this occurs in the ghost-moth (Hepialus humuli), which, before it retires into the earth, feeds upon the roots of the hop or the burdock. Like other insects which construct cells under ground, it lines the cemented earthen walls of its cell with a smooth tapestry of silk, as closely woven as the web of the house- spider. Inaccurate observers have inferred that these earthen structures were formed by a very rude and imskilful process — the caterpillar, according to them, doing nothing more than roll itself round, while the mould adhered to the gluey perspiration with which they describe its body to be covered. This is a process as far from the tiTith as Aristotle's account of the spider spinning its web from wool taken from its body. Did the caterpillar do nothing more than roll itself in the earth, the cavity would be a long 176 INSECT ARCHITECTURE. tiihe fitted exactly to its body {fig. c.) : it is essentially different. Nests, &c., of an Earth-mason Caterpillar. It does not indeed require very minute observation to perceive, that every grain of earth in the structure is united to the contiguous grains by threads of silk ; and that consequently, instead of the whole having been done at once, it must have required very considerable time and labour. Thi^ construction is rendered more obvious by throwing one of these earthen cases into water, which dissolves tlie earth, but does not act on the silk which binds it together. To understand how this is performed, it may not be uninteresting to follow the little mason from the beginning of his task. When one of those burrowing caterpillars has done feed- ing, it enters the earth to the depth of several inches, till it finds mould fit for its purpose. Having noAvhere to throw the earth which it may dig out, the only means in its power (jf forming a cavity is to press it with its body ; and, by EARTH-MASON CATERPILLARS. 177 turning round and round for this purpose, an oblong hollow is soon made. But were it left in this state, as Eeaumur well remarks, though the vault might endure the requisite time by the viscosity of the earth alone, were no change to take place in its humidity, yet, as a great number are wanted to hold out for six, eight, and ten months, they require to be substantially built ; a mere lining of silk, therefore, would not be sufficient, and it becomes necessary to have the walls bound with silk to some thickness. When a caterpillar cannot find earth sufficiently moist to bear kneading into the requisite consistence, it has the means of moistening it with a fluid which it ejects for the purpose ; and as soon as it has thus prepared a small pellet of earth, it fits it into the wall of the vault, and secures it with silk. As the little mason, however, always works on the inside of the building, it does not, at first view, appear in what manner it can procure materials for making one or two additional walls on the inside of the one first built. As the process takes place under ground, it is not eas}^ to discover the particulars, for the cater]3illars will not work in glazed boxes. The difiiculty was completely overcome by M. Reaumur, in the instance of the caterpillar of the water-betony moth (CiicuUia scrophularice, Scheank), which he permitted to construct the greater part of its under- ground building, and then dug it up and broke a portion off from the end, leaving about a third part of the whole to be rebuilt. Those who are unacquainted with the instinct of insects might have supposed that, being disturbed by the demolition of its walls, it would have left off work ; but the stimulus of providing for the great change is so powerful, that scarcely any disturbance will interrupt a caterpillar in this species of labour. The little builder, accordingly was not long in recom- mencing its task for the purpose of repairing the disorder, which it accomplished in about four hours. At first it pro- truded its body almost entirely beyond the breach which had been made, to reconnoitre the exterior for building ma- terials. Earth was put within its reach, of the same kind as it had previously used, and it was not long in selecting 178 TxsECT architecturp:. a orain adapted to its purpose, which it fitted into the wall and secured with silk. It first enlarged the outside of the wall by the larger and coarser grains, and then selected finer for the interior. But before it closed the aperture, it collected a quantity of earth on the inside, wove a pretty ^^^%. Earth-mason Caterpillar's Xests, with the perfect .Aloth, &c thick network tapestry of silk over the part which remained open, and into the meshes of this, by pushing and pressing, it thrust grains of earth, securing them with silk till the EARTH-MASON CATERPILLARS. 179 wliole was rendered opaque ; and the further operations of the insect could no longer be watched, except that it was observed to keep in motion, finishing, no doubt,. the silken tapestry of the interior of its little chamber. When it was completed, M. Eeaumur ascertained that the portion of the structure which had been built under his eye was equally thick and compact with the other, which had been done under ground. The grubs of several of the numerous species of may-fly (^Ephernerd) excavate burrows for themselves in soft earth, on the banks of rivers and canals, under the level of the water, an operation well described by Scopoli, Swammer- dam, and Eeaumur. The excavations are always pro- portioned to the size of the inhabitant ; and consequently, when it is young and small, the hole is proportionally small, though, with respect to extent, it is alwaj^s at least double the length of its body. The hole, being under the level of the river, is always filled with water, so that the grub swims in its native element, and while it is secure from being preyed upon by fishes, it has its own food within easy reach. It feeds, in fact, if we may judge from its egesta, upon the slime or moistened clay with which its hole is lined. In the bank of the stream at Lee, in Kent, we had occasion to take up an old willow stump, which, previous to its being driven into the bank, had been perforated in numerous places by the caterpillar of the goat-moth (Cossus ligniperda). From having been driven amongst the moist clay, these perforations became filled with it, and the grubs of the ephemerae found them very suitable for their habitation ; for the wood supplied a more secure protection than if their galleries had been excavated in the cla}^ In these holes of the wood we found several empty, and some in which were full-grown grubs. (J. E.) The architecture of the grub of a pretty genus of beetles, known to entomologists by the name of Cincindela, is pecu- liarly interesting. It was first made know;n by the eminent French naturalists, Geoifroy, Desmarest, and Latreille. This grub, which may be met with during spring, and also in 180 INSECT ARCHITECTURE. summer and autimm, in sandy places, is long, cylindric, soft, wliitish, and fumislied with six scaly brown feet. The head is of a square form, with six or eight eyes, and very large in proportion to the body. They have strong A, The Gnib. Nest of the Grubs of Ephemera. 5, Perforations in a river banl^. C, One laid open to show the parallel structure. jaws, and on the eighth joint of the body there are two fleshy tubercles, thickly clothed with reddish hairs, and armed Avith a recurved horny spine, the whole giving to the grub the form of the letter Z. Nests of Ephemera^ in holes of Cossus. With their jaws and feet they dig into the earth to the depth of eighteen inches, forming a cylindrical cavity of greater diameter than their body, and furnished with a perpendicular entrance. In constructing this, the giub EARTH-MASON CATERPILLARS, 181 first clears away the particles of earth and sand by placing them on its broad trapezoidal head, and carrying the load in this manner beyond the area of the excavation. AVhen it gets deeper down, it climbs gradually up to the surface with similar loads by means of the tubercles on its back, above described. This process is a work of considerable time and difficulty, and in carrying its loads the insect has often to rest by the way to recover strength for a renewed exertion. Not unfrequently, it finds the soil so ill adapted to its operations, that it abandons the task altogether, and begins anew in another situation. A\ hen it has succeeded in forming a complete den, it fixes itself at the entrance by the hooks of its tubercles, which are admirably adapted for the purpose, forming a fulcrum or support, while the broad plate on the top of the head exactly fits the aperture of the excavation, and is on a level with the soil. In this position the grub remains immovable, with jaws expanded, and ready to seize and devour every insect which may wander Avithin its reach, particularly the smaller beetles; and its voracity is so great, that it does not spare even its own species. It precipitates its prey into the excavation, and in case of danger it retires to the bottom of its den, a circumstance which renders it not a little difficult to discover the grub. The method adopted l)y the French naturalists was to introduce a straw or pliant twig into the hole, while they dug away, l^y degrees and with great care, the earth aroinid it, and usually found the grub at the bottom of the cell, resting in a zig-zag position like one of the caterpillars of the geometric moths. When it is about to undergo its transformation into a pupa, it carefully closes the mouth of the den, and retires to the bottom in security. It does not appear that the grub of the genus Cincin- dela uses the excavation just described for the purpose of a trap or pitfall, any further than that it can more efi"ec- tually secure its prey by tumbling them down ^into it ; but there are other species of grubs which construct pit- falls for the express purpose of traps. J\mong these is the larva of a fly {Rhagio vermileo), not unlike the common 182 ' IXSECT ARCHITECTURE. flesh maggot. The den which it constructs is in the form of a funnel, the sides of which are composed of sand or loose earth. It forms this pitfall of considerable depth, by throwing out the earth obliquely on all sides ; and when its trap is finished, it stretches itself along the bottom, remaining stiff and motionless, like a piece of wood. The last segment of the body is bent at an angle with the rest, so as to form a strong point of support in the struggles which it must often have to encounter with vigorous prey. The instant that an insect tumbles into the pitfall, the grub pounces upon it, writhes itself round it like a serpent, transfixes it with its jaws, and sucks its juices at its ease. Should the prey by any chance escape, the gi'ub hurls up jets of sand and earth, with astonishing rapidity and force, and not unfrequently succeeds in again precipitating it to the bottom of its trap. The Ant-Lion. The observations of the continental naturalists have made known to us a pitfall constructed hy an insect, the details of whose operations are exceedingly curious ; we refer to the grub of the ant-lion (Mijnndeon fonnicarius), which, though marked by Dr. Turton and Mr. Stewaii; as British, has not (at least of late years) been found in this country. As it is not, however, uncommon in France and Switzerland, it is probable it may yet be discovered in some spot hitherto imexplored, and if so, it will well reward the search of the curious. The ant-lion grub being of a grey colour, and having its body composed of rings, is not unlike a wood-louse (Oniscus), though it is larger, more triangular, has only six legs, and most formidable jaws, in form of a reaping- hook, or a pair of calliper compasses. These jaws, how- ever, are not for masticating, but are perforated and tubular, for the purpose of sucking the juices of ants upon which it feeds. Vallisnieri was therefore mistaken, as Eeaumur well remarks, when he supposed that he had discovered its mouth. Its habits require that it should walk backwaids, and this is the only species of locomo- THE ANT-LION. 183 tion which it can perform. Even this sort of motion it executes very slowly ; and were it not for the ingenuity of its stratagems, it would fare but sparingly, since its chief food consists of ants, whose activity and swiftness of foot would otherwise render it imj)ossiLle for it to make a single capture. Nature, however, in this, as in nearly every other case, has given a compensating power to the individual animal, to balance its privations. The ant-lion is slow, but it is extremely sagacious; it cannot follow its prey, but it can entrap it. The snare which the grub of the ant-lion employs con- sists of a funnel-shaped excavation formed in loose sand, at A " « f Grub of the Ant-Liuii, masuiaed, with ouc perfect Trap, and aiiuther begun. the bottom of which it lies in wait for the ants that chance to stumble over the margin, and cannot, from the loose- ness of the walls, gain a sufficient footing to effect their escape. By shutting up one of these grubs in a box with loose sand, it has been repeatedly observed constructing its trap of various dimensions, from one to nearl}^ three inches in diameter, according to circumstances. .184 IXSECT ARCHITECTURE. In the 'Magazine of Natural History,' 1838, p. 601, Mr. Westwood gives a very interesting acconnt of the mode in which the ant-lion proceeds in the excavation of its pitfall, as witnessed by himself in specimens procured in the Pare de Belle Yue, near Paris, where, at the foot of a very high sand-bank, these pits were numerous, and of various sizes, but none exceeded an inch and a half or two inches in diameter, and two-thirds of an inch deep. " The ant-lions were of various sizes, corresponding to the size of their retreats. I brought many of them to Paris, placing several together in a box filled with sand. They, however, destroyed one another wdiilst shut up in these boxes ; and I only succeeded in bringing three of them alive to England, one of which almost immediately afterwards (on the 23rd of July) enclosed itself in a globu- lar cocoon of fine sand. The other two afforded me man}^ opportunities of observing their proceedings. They were unable to walk forwards, — an anomalous circnmstance, and not often met with in animals furnished with well-deve- loped legs. It is generally backwards, working in a spiral direction, that the creature moves, pushing itself backwards and downwards at the same time, the head being carried horizontally, and the back much arched, so that the ex- tremity of the body is forced into the sand. In this manner it proceeds backwards (to use an Tlibernianism), forming little mole-hills in the sand. But it does not appear to me that this retrograde motion has anything to do with the actual formation of the cell, since, as soon as it has fixed upon a spot for its retreat, it commences throwing up the sand with the back of its head, jerking the sand either behind its back or on one or the other side. It shuts its long jaws, forming them into a kind of shovel, the sharp edges of which it thrusts laterally into the sand on each side of its head, and thereby contrives to lodge a quantity of the sand upon the head as well as the jaws. The motion is in fact something like that of the head of a goat, especially when butting sideways in play. In this manner it contrives to throw away the sand, and by degrees to make a hole entirely with its head, the ft^ur legs not THE AXT-LION. 185 affording the slightest assistance in the operation. During this performance the head only is exposed, the insect having previously pushed itself beneath the surface of the sand ; but when it has made the hole sufficiently deep, it withdraws the head also, leaving only the jaws exposed, which are spread open in a line, and laid on the sand so as to be scarcely visible. If alarmed, the insect imme- diately takes a step backwards, withdrawing the jaws ; but when an insect falls into the hole, the jaws are instinc- tively and instantaneously closed, and the insect seized by the leg, wing, or body, just as it may chance to fall within the reach of the ant-lion's jaws. If, however, the insect be not seized, but attempts to escape, no matter in what direction, the ant-lion immediately begins twisting its head about, and shovelling up the sand with the greatest agility, jerking it about on each side and backwards, but never forwards, as misrepresented in some figures, until the hole is made so much deeper, and such a disturbance caused in the sides of the hole, that the insect is almost sure to be brought down to tlie bottom, when it is seized by the ant- lion, which immediately endeavours to draw it beneath the sand ; and if it be very boisterous, the ant-lion beats it about, holding it firmly by the jaws until it is too weak for further resistance. Hence, as the head of the ant-lion is immersed in the sand, it is evident that the accounts given in popular works of the instinct by which it throws the sand in the direction of the escaping prey is not quite correct. The act of throwing up the sand, when an insect has fallen into the pit and attempts to escape, has evidently for its chief object that of making the pit deeper and more conical, and therefore more difficult of ascent." It is by the action of the hinder pair of its legs that the ant-lion drags itself backwards, the other four pair being extended trailing after it, and leaving an impression on the surface of the fine sand over which it has passed ; and when burrowing its way beneath the surface of the sand, it proceeds by short steps backwards. A portion of sand at each step is thrown on the head, owing to the hump-like form of the back: this is immediately jerked 186 INSECT ARCHITECTURE. awa}^ tlie body at the same time advancing another step in its backward and spiral motion. Where it rests, a little hillock of sand is raised by the body of the ant-lion undei'neath ; while its jaws emerge and spread flat on the surface. It now probably commences its pitfall, the mode of excavating which we have given in detail. From the spiral course described by the ant-lion in its backward progress, appears to have arisen the idea of its tracing out a circle as the outline of its pitfall — as would an architect or engineer ; but whence sprang the often- repeated state- ment, that the ant-lion loads its head with, sand by means of one of its legs, that nearest the centre of the circle, we cannot conjecture. Nor do we know how, as it works entirely buried with the exception of the head, the ant-lion can act when it meets with a stone or other obstacle, as M. Bonnet states he has repeatedly witnessed. He observes that if the stone be small, it can manage to jerk it out in the same manner as the sand ; but when it is two or three times larger and heavier than its own bod}^ it must have Ant-Lion's Pitfalls, in an expcrimenting-box. recourse to other means of removal. The larger stones it usually leaves till the last ; and when it has removed all the sand which it intends, it then proceeds to try what it can do with the less manageable obstacles. For this purpose it crawls backwards to the place where a stone may be, and thrusting its tail under it, is at great pains to get it properly balanced on its back, by an alternate motion of the rings composing its body. When it has succeeded in adjusting the stone, it crawls up the side of the pit with great care, and deposits its burthen on the outside of the THE ANT-LION. 187 circle. Should the stone happen to be round, the balance can be kept only with the greatest difficnlty, as it has to travel with its load upon a slope of loose sand, which is ready to give way at every step ; and often when the insect has carried it to the very brink, it rolls off" its back and tumbles down to the bottom of the pit. This accident, so far from discouraging the ant-lion, only stimulates it to more persevering efforts. Bonnet observed it renew these attempts to dislodge a stone five or six times. It is only when it finds it utterly impossible to succeed, that it abandons the design and commences another pit in a fresh situation. When it succeeds in getting a stone beyond the line of its circle, it is not contented with letting it rest there ; but to prevent it from again rolling in, it goes on to push it to a considerable distance. We may be pardoned for pausing before we give full credence to these details. The ant-lion feeds only on the blood or juice of insects ; and as soon as it has extracted these, it tosses the dry carcase out of its den. When it is about to change into a pupa, it proceeds in nearly the same manner as the caterpillar of the water- hetonj iRoth. (CiicalUa scrophrdarice). It first builds a case of sand, the particles of which are secured by threads of silk, and then tapestries the whole with a silken web. Within this it undergoes its transformation into a pupa, and in due time it emerges in form of a four-winged fly, closely resembling the dragon-flies (LibeUidce), vulgarly and erroneously called horse-stingers. The instance of the ant-lion naturally leads us to con- sider the design of the Author of Nature in so nicely adjusting, in all animals, the means of destruction and of escape. As the larger quadrupeds of prey are provided with a most ingenious machinery for preying on the weaker, so are these furnished with the most admirable powers of evading their destroyers. In the economy of insects, we constantly observe that the means of defence, not only of the individual creatures, but of their larvae and pupae, against the attacks of other insects, and of 188 INSECT ARCHITECTURE. birds, is proportioned, in the ingenuity of their arrange- ments, to the weakness of the insect employing them. Those species which multiply the quickest have the greatest number of enemies. Bradley, an English natur- alist, has calculated that two sparrows carry, in the course of a week, above three thousand caterpillars to the young in their nests. But though this is, probably, much beyond the truth, it is certain that there is a great and constant destruction of . individuals going forward ; and yet the species is never destroyed. In this way a balance is kept up, by which one portion of animated nature cannot usurp the means of life and enjoyment which the world offers to another portion. In all matters relating to reproduction. Nature is prodigal in her arrangements. Insects have more stages to pass through before they attain their perfect growth than other creatures. The continuation of the species is, therefore, in many cases, provided for by a much larger number of eggs being deposited than ever become fertile. How many larvae are produced, in com- parison with the number which pass into the pupa state ; and how many pupse perish before they become perfect insects I Every garden is covered with caterpillars ; and yet how few moths and butterflies, comparatively, are seen, even in the most sunnj^ season ! Insects which lay few eggs are, commonly, most remarkable in their contrivances for their preservation. The dangers to which insect life is exposed are manifold ; and therefore are the contrivances for its preservation of the most perfect kind, and invariably adapted to the peculiar habits of each tribe. The same wisdom determines the food of every species of insect ; and thus some are found to delight in the rose-tree, and some in the oak. Had it been otherwise, the balance of vegetable life would not have been preserved. It is for this reason that the contrivances which an insect employs for obtaining its food are curious, in proportion to the natural difficulties of its structure. The ant-lion is car- nivorous, but he has not the quickness of the spider, nor can he spread a net over a large surface, and issue from his citadel to seize a victim which he has caught in his out- THE ANT-LIOX. 189 works. He is therefore taught to dig a trap, where he sits like the unwieldy giants of fable, waiting for some feeble one to cross his path. How laborious and patient are his operations — how uneei-tain the chances of success ! Yet he never shrinks frpm them, because his instinct tells him that by these contrivances alone can he preserve his own existence, and continue that of his species. ( i?o ) CHAPTER XII. CLOTHES-MOTH AND OTHER TEXT-MAKING CATERPILLARS. — LEAF AND BARK MINERS. There are at least five different species of moths similar in manners and economy, the caterpillars of which feed upon animal substances, such as furs, woollen cloths, silk, leather, and, what to the naturalist is no less vexing, upon the specimens of insects and other animals preserved in his cabinet. The moths in question are of the family named Tinea by Entomologists, such as the tapestrA^-moth (^Tinea tapetzelld), the fur-moth {^Tinea peUioneUa), the wool-moth {Tinea vestianella), the cabinet-moth (^Tinea destructor, Ste- phens), &c. The moths themselves are, in the Avinged state, small and well fitted for making their way through the most minute hole or chink, so that it is scarcely possible to exclude them by the closeness of a wardrobe or a cabinet.* If they cannot effect an entrance when a drawer is out, or a door open, they will contrive to glide through the key-hole ; and if they once get in, it is no easy matter to dislodge or destroy them, for they are exceedingly agile, and escape out of sight in ^ moment. Moufet is of opinion that the ancients possessed an effectual method of preserving stuffs from the moth, because the robes of Servius Tullius were preserved up to the death of Sejanus, a period of more than five hundred years. On turning to Pliny to learn this secret, we find him relating that stuff laid upon a coffin will be ever after safe from moths ; in the same way as a person once stung by a scorpion will never afterwards be stung by a bee, or a wasp, or a homet ! Rh^sis again says that cantharides suspended in a house drive away moths ; and, * See fig. d., p. 193. MOTH-CATERPILLARS. 191 he adds, that they will not touch anything wrapped in a lion's skin ! — the poor little insects, says Eeaunmr sarcasti- cally, being probably in bodily fear of so terrible an animal.* Such are the stories which fill the imagination even of philosophers, till real science entirely expels them. The effluvium of camphor or turpentine, or fumigation by sulphur or chlorine, may sometimes kill them, when in the winged state, but this will have no effect upon their eggs, and seldom upon the caterpillars ; for they wrap themselves up too closely to be easily reached by any agent except heat. This, when it can be conveniently applied, will be certain either to dislodge or to kill them. When the effluvium of turpentine, however, reaches the caterpillar, Bonnet says it falls into convulsions, becomes covered with livid blotches, and dies.f The mother insect takes care to deposit her eggs on or near such substances as she instinctively foreknows will be best adapted for the food of the young, taking care to distribute them so that there may be a plentiful supply and enough of room for each. We have found, for example, some of those caterpillars feeding upon the shreds of cloth used in training wall-fruit trees ; but we never saw more than two caterpillars on one shred. This scattering of the eggs in many places renders the effects of the caterpillars more in- jurious, from their attacking many parts of a garment or a piece of stuff at the same time. (J. E.) When one of the caterpillars of this family issues from the egg, its first care is to provide itself with a domicile, which indeed seems no less indispensable to it than food ; for, like all caterpillars that feed under cover, it will not eat while it remains unprotected. Its mode of building is very similar to that which is employed by other caterpillars that make use of extraneous materials. The foundation or frame-work is made of silk secreted by itself, and into this it interweaves portions of the material upon which it feeds. It is said by Bingley, that " after having spun a fine coating of silk immediately around its body, it cuts the filaments of the * Reaumur, 'Mem. Hist, Insectes,' iii. 70. t ' Contemplation de la Nature,' part xii. chap. x. note. 192 INSECT ARCHITECTURE. wool or fur close by the thread of the cloth, or by the skin, with its teeth, which act in the manner of scissors, into con- venient lengths, and applies the bits, one by one, with gi'eat dexterity, to the outside of its silken case."* This statement, however, is erroneous, and inconsistent with the proceed- ings not only of the clothes -moth, bnt of every caterpillar that constructs a covering. None of these build from within outwards, but uniformly commence with the exterior wall, and finish by lining the interior with the finest materials. Eeaumur, however, found that the newly-hatched caterpil- lars lived at first in a case of silk. We have repeatedly witnessed the proceedings of these insects from the very foundation of their structures ; aiKl, at the moment of writing this, we turned out one from the carcase of an " old lady moth" (^Mormo maura^ Ochsenheim) in our cabinet, and placed it on a desk covered with green cloth, where it might find materials for constructing another dwelling. It wandered about for half a day before it began its operations ; but it did not, as is asserted by Bonnet, and Kirby and Spence, "in moving from place to place, seem to be as much incommoded by the long hairs which surround it, as we are by walking amongst high grass," nor, " accordingly, marching scythe in hand," did it, " with its teeth, cut out a smooth road." f On the contrary, it did not cut a single hair till it selected one for the foundation of its intended structure. This is cut very near the cloth, in order, we suppose, to have it as long as possible ; and placed it on a line with its body. It then immediately cut another, and placing it parallel to the first, bound both together with a few threads of its own silk. The same process was repeated with other hairs, till the little creature had made a fabric of some thickness, and this it went on to extend till it was large enough to cover its body ; which (as is usual with caterpillars) it employed as a model and measure for regulating its opera- tions. Wq remarked that it made choice of longer hairs * 'Animal Biography,' vol. iii, p. 330, Third Edition, t Bonnet, xi. p. 204 ; Kirby and Spence, ' Introduction,' i. 464, Fifth Edition. I MOTH-G ATERriLLARS. 193 for the outside tlian for the parts of the interior, which it thought necessary to strengthen by fresh additions ; but the chamber was ultimately finished by a fine and closel}^- woven tapestry of silk. We could see the progress of its work, by looking into the opening at either of the ends ; for at this stage of the structure the walls are quite opaque, and the insect concealed. It may be thus observed to turn round, by doubling itself and bringing its head where the tail had just been ; of course, the interior is left wide enough for this purpose, and the centre, indeed, where it turns, is always wider than the extremities. (J.R.) When the catei'pillar increases in length, it takes care to add to the length of its house, by working-in fresh Cases, &c., of the Clothes-Moth (Tinea j^Mionella).— a, CuierpWhxr feeding in a case, which has heen lengthened by ovals of different colours; b, Case cut at the ends for experiment; c, Case cut open by the insect for enlarging it; d, e. The clothes-moths in their perfect state, when, as they cease to eat, they do no further injury. hairs at either end ; and if it be shifted to stuffs of dif- ferent colours, it may be made to construct a party- coloured tissue, like a Scotch plaid. Eeaumur cut off" with scissors a portion at each end, to compel the insect to make up the deficiency. But the caterpillar increases in thickness as well as in length, so that, its first house becoming too narrow, it must either enlarge it, or build a new one. It prefers the former as less troublesome, and accomplishes its purpose "as dexterously," says 194 INSECT ARCHITECTURE. Bonnet, " as any tailor, and sets to work precisely as we should do, slitting the case on the two opposite sides, and then adroitly inserting between them two pieces of the requisite size. It does not, however, cut open the case from one end to the other at once ; the sides would separate too far asunder, and the insect be left naked. It therefore first cuts each side about half-way doMoi, beginning sometimes at the centre and sometimes at the end (Fig. c), and then, after having filled up the fissure, proceeds to cut the remaining half ; so that, in fact, four enlargements are made, and four separate pieces inserted. The colour of the case is always the same as that of the stuff from which it is taken. Thus, if its original colour be blue, and the insect, previously to enlarging it, be put upon red cloth, the circles at the end, and two stripes down the middle, will be red." * Eeaumur found that they cut these enlargements in no precise order, but some- times continuously, and sometimes opposite each other, indifferently. The same naturalist says he never knew one leave its old dwelling in order to build a new ; though, when once ejected by force from its house, it would never enter it again, as some other species of caterpillars will do, but always preferred building another. We, on the contrary, have more than once seen them leave an old habitation. The very caterpillar, indeed, whose history we have above given, first took up its abode in a specimen of the ghost- moth (Hepialus humuli), where, finding few suitable mate- rials for building, it had recourse to the cork of the drawer, with the chips of which it made a structure almost as warm as it would have done from wool. Whether it took offence at our disturbing it one day, or whether it did not find sufficient food in the body of the ghost-moth, we know not ; but it left its cork house, and travelled about eighteen inches, selected " the old lady," one of the largest insects in the drawer, and built a new apartment, composed partly of cork as before, and partly of bits dipt out of the moth's wings. (J. R.) * BoniiL't, vol. ix. p. 203. TENT-MAKING CATERPILLARS. 195 We have seen these caterpillars form their habitations of every sort of insect, from a butterfly to a beetle ; and the soft, feathery wings of moths answer their purpose very well : but when they fall in with such hard materials as the musk heetle (Cerambyx moschat us), or the large scolo- pendra of the West Indies, they find some difficulty in the building. When the structure is finished, the insect deems itself secure to feed on the materials of the cloth or other animal matter within its reach, provided it is dry and free from fat or grease, which Reaumur found it would not touch. This may probably be the origin of the practice of putting a bit of candle with furs, &c., to pre- serve them from the moth. For building, it always selects the straightest and loosest pieces of wool, but for food it prefers the shortest and most compact ; and to procure these it eats into the body of the stuff, rejecting the pile or nap, which it necessarily cuts across at the origin, and permits to fall, leaving it threadbare, as if it had been much worn. It must have been this circumstance which induced Bonnet to fancy (as we have already mentioned) that it cuts the hairs to make itself a smooth, comfortable path to walk upon. It would be equally correct to .say that an ox or a sheep dislikes walking amongst long grass, and therefore eats it down in order to clear the way. Tent-makixg Caterpillars. The caterpillars of a family of small moths (Tineidce), which feed on the leaves of various trees, such as the hawthorn, the elm, the oak, and most fruit-trees, particu- larly the pear, form habitations which are exceedingly ingenious and elegant. They are so very minute that they require close inspection to discover them ; and to the cursory observer, unacquainted with their habits, they will appear more like the withered leaf-scales of the tree, thrown off when the buds expand, than artificial structures made by insects. It is only, indeed, by seeing them move about upon the leaves, that we discover they are inhabited 196 INSECT AKCHITECTURE. by a living tenant, who carries them as the snail does its shell. These tents are from a quarter of an inch to an inch in length, and usually about the breadth of an oat-straw. That they are of the colour of a withered leaf is not surprising ; for they are actually composed of a piece of leaf; not, however, cut out from the whole thickness, but artfully separated from the upper layer, as a person might separate one of the leaves of paper from a sheet of paste- board. The tents of this class of caterpillars, which are found on the elm, the alder, and other trees with serrated leaves, are much in the shape of a minute goldfish. They are A caterpillar's tent upon a leaf of the elm.— a, a, the part of the leaf from which the tent has been cut out; b, the tent itself. convex on the back, where the indentations of the leaf out of which they have been cut add to the resemblance, by appearing like the dorsal fins of the fish. By depriving one of those caterpillars common on the hawthorn of its tents, for the sake of experiment, we put it under the necessity of making another; for, as Pliny remarks of the clothes-moth, they will rather die of hunger than feed unprotected. AVhen we placed it on a fresh haw- thorn leaf, it rejDeatedly examined every part of it, as if seeking for its lost tent, though, when this was put in its way, it would not again enter it ; but, after some delay, commenced a new one. (J. E.) For this purpose, it began to eat through one of the two outer membranes which compose the leaf and enclose the pulp (parenchi/ma), some of which, also, it devoured, and then thrust the hinder part of its body into the per- TENT-MAKING CATERPILLARS. 197 foration. The cavity, however, which it had formed, being yet too small for its reception, it immediately re- sumed the task of making it larger. By continuing to gnaw into the pulp, between the membranes of the leaf (for it took the greatest care not to puncture or injure the membranes themselves), it soon succeeded in mining out a gallery rather larger than was sufficient to contain its bod3\ We perceived that it did not throw out as rubbish the pulp it dug into, but devoured it as food — a circumstance not the least remarkable in its proceedings. As the two membranes of leaf thus deprived of the enclosed pulp appeared white and transpai'ent, every movement of the insect within could be distinctly seen ; and it was not a little interesting to watch its ingenious operations while it was making its tent from the mem- branes prepared as we have just described. These, as Reaumur has remarked, are in fact to the insect like a piece of cloth in the hands of a tailor ; and no tailor could cut out a shape with more neatness and dexterity than this little workman does. As the caterpillar is furnished in its mandibles with an excellent pair of scissors, this may not appear to be a difficult task ; yet, when we examine the matter more minutely, we find that the peculiar shape of the two extremities requires different curvatures, and this, of course, renders the operation no less complex, as Reaumur subjoins, than the shaping of the pieces of cloth for a coat.* The insect, in fact, shapes the membranes slightly convex on one side and concave on the other, and at one end twice as large as the other. In the instance which we observed, beginning at the larger end, it bent them gently on each side by pressing them with its body thrown into a curve. We have not said it cuts, but shapes its materials ; for it must be obvious that if the insect had cut both the membranes at this stage of its operations, the pieces would have fallen and carried it along with them. To obviate such an accident it proceeded to join the two edges, and secure them firmly with silk, before it made * 'Mem. Hist. Insect.' iii. p. 106. 198 IXSECT ARCHITECTURE. a single incision to detach them. When it had in this manner joined the two edges along one of the sides, it inserted its head on the outside of the joining, first at one end and then at the other, gnawing the fibres till that whole side was separated. It proceeded in the same manner with the other side, joining the edges before it cut them ; and when it arrived at the last fibre, the only remaining support of its now finished tent, it took the precaution, before snipping it, to moor the whole to the uncut part of the leaf by a cable of its own silk. Con- sequently, when it does cut the last nervure, it is secure from falling, and can then travel along the leaf, carrying its tent on its back, as a snail does its shell. (J. E.) We have just discovered (Nov. 4th, 1829) upon the nettle a tent of a very singular appearance, in consequence of the materials of which it is made. The caterpillar a, The Ciiterpillar occupying the space it has eaten between the cuticle of the leaf; h, A portion of the upper cuticle, cut out for the formation of the tent; c, The tent nearly completed ; d. The perfect tent, with the caterpillar protruding its head. seems, indeed, to have proceeded exactly in the same manner as those which we have described, mining first between the two membranes of the leaf, and then uniting these and cutting out his tent. But the tent itself looks singular from being all over studded with the stinging bristles of the nettle, and forming a no less formidable coat of mail to the little inhabitant than the spiny hide of the hedgehog. In feeding it does not seem to have mined into the leaf, but to have eaten the whole of the lower membrane, along with the entire pulp, leaving STONE-MASON CATERPILLARS. 190 nothing but the upper membrane nntonched. (J. E.) During the summer of 1830 we discovered a very large tent which had been formed out of a blade of grass ; and another stuck all over with chips of leaves upon the common maple. Tents of Stone-Mason Caterpillars. The caterpillar of a small moth {Tinea) which feeds upon the lichens growing on walls, builds for itself a moveable tent of a very singular kind. M. de la Voye was the first who described these insects ; but though they are frequently overlooked, from being ver}^ small, they are by no means uncommon on old walls. Eeaumur observed them regularly for twenty years together on the terrace- wall of the Tuileries at Paris ; and they may be found in abundance in similar situations in this country. This accurate observer refuted by experiment the notion of Lichen-Tents and Caterpillars, both of their natural size and magnitied. M. de la Voye that the caterpillars fed upon the stones of the wall ; but he satisfied himself that they detached particles of the stone for the purpose of building their tents or sheaths (fourreaux), as he calls their dwellings. In order to watch their mode of building, Eeaumur gently ejected half-a-dozen of them from their homes, and ob- served them detach grain after grain from a piece of stone, binding each into the wall of their building with silk till the cell acquired the requisite magnitude, the whole operation taking about twenty-four hours of continued 200 INSECT ARCHITECTURE. labour. M. de la Voye mentions small granular bodies of a greenish colour, placed irregularly on the exterior of the structure, which he calls eggs ; but we agree with Eeaumur in thinking it more probable that they are small fragments of moss or lichen intermixed with the stone : in fact, we have ascertained that they are so. (J. E.) \Mien these little architects prepare for their change into chrysalides before becoming moths, they attach their tents securely to the stone over which they have hitherto rambled, by spinning a strong mooring of silk, so as not only to fill up every interstice between the main entrance .of the tent and the stone, but also weaving a close, thick curtain of the same material, to Shut up the entire aperture. It is usual for insects which form similar structure to issue, when they assume the winged state, from the broader end of their habitation ; but our little stone-mason proceeds in a different manner. It leaves open the apex of the C(5ne from the first, for the purpose of ejecting its excrements, and latterly it enlarges this opening a little, to allow of a free exit when it acquires wings ; taking care, however, to spin over it a canopy of silk, as a temporary protection, which it can afterwards burst through without difficulty. The moth itself is very much like the common clothes-moth in form, but is of a gilded-bronze colour, and considerably smaller. In the same locality, M. de Maupertuis found a nume- rous brood of small caterpillars, which employed grains of stone, not, like the preceding, for building feeding-tents, but for their cocoons. This caterpillar was of a brownish- grey colour, with a white line along the back, on each side of which were tufts of hair. The cocoons which it built were oval, and less in size than a hazel-nut, the grains of the stone being skilfully woven into irregular meshes of silk. In June, 1829, we found a numerous encampment of the tent-building caterpillars described by MM. de la Voye and Eeaumur, on the brick wall of a garden at Blackheath, Kent. (J. E.) They were so very small, however, and so like the lichen on the wall, that had not our attention STONE-MASOX CATERPILLARS. 201 been previously directed to their habits, we should have considered them as portions of the wall ; for not one of them was in motion, and it was only by the neat, turbi- nated, conical form in which they had constructed their habitations that we detected them. We tried the experi- ment above-mentioned, of ejecting one of the caterpillars from its tent, in order to watch its proceedings when constructing another; but probably its haste to procure shelter, or the artificial circumstances into which it was thrown, influenced its operations, for it did not form so good a tent as the first, the texture of the v/alls being much slighter, while it was more rounded at the apex, and of course not so elegant. Reaumur found, in all his similar experi- ments, that the new structure equalled the old ; but most of the trials of this kind which we have made correspond with the inferiority which we have here recorded. The process indeed is the same, but it seems to be done with more hurry and less care. It may be, indeed, in some cases, that the supply of silk necessary to unite the bits of stone, earth, or lichen employed, is too scanty fur perfecting a second structure. We remarked a very singular circumstance in the opera- tions of our little architect, which seems to have escaped the minute and accurate attention of Reaumur. When it commenced its structure, it was indispensable to lay a foundation for the walls about to be reared ; but as the tent was to be moveable like the shell of a snail, and not stationary, it would not have answered its end to cement the foundation to the wall. We had foreseen this difficulty, and felt not a little interested in discovering how it would be got over. Accordingly, upon watching its movements with some attention, we were soon gratified to perceive that it used its own body as the primary support of the building. It fixed a thread of silk upon one of its right feet, warped it over to the corresponding left foot, and upon the thread thus stretched between the two feet it glued grains of stone and chips of lichen, till the wall was of the required thickness. Upon this, as a foundation, it continued to work till it had formed a small portion in 202 INSECT ARCHITECTURE. foiin of a parallelogram ; and proceeding in a similar way, it was not long in making a ring a ver}^ little wider than sufficient to admit its body. It extended this ring in breadth, by working on the inside only, narrowing the diameter by degrees, till it began to take the form of a cone. The apex of this cone was not closed np, but left as an ajDerture through which to eject its excrements. It is worthy of remark, that one of the caterpillars which we deprived of its tent, attempted to save itself the trouble of building a new one, b}^ endeavouring to unhouse one of its neighbours. For this purpose, it got upon the outside of the inhabited tent, and, sliding its head down to the entrance, tried to make its way into the interior. But the rightful owner did not choose to give up his 23i*emises so easily; and fixed his tent down so firmly upon the table where we had placed it, that the intruder was forced to abandon his attempt. The instant, however, that the other unmoored his tent and began to move about, the invader renewed his efforts to eject him, persevering in the struggle for several hours, but without a chance of success. At one time we imagined that he would have accomplished his felonious intentions ; for he bound down the apex of the tent to the table with cables of silk. But he attempted his entrance at the wrong end. He ought to have tried the aperture in the apex, by enlarging which a little he would undoubtedly have made good his entrance ; and as the inhabitant could not have turned upon him for want of rooui, the castle must have been surrendered. This experiment, however, was not tried, and there was no hope for him at the main entrance. Muff-shaped Tents. The ingenuity of man has pressed into his sei-vice not only the wool, the hair, and even the skins of animals, but has most extensively searched the vegetable kingdom for the materials of his clothing. In all this, however, he is rivalled by the tiny inhabitants of the insect world, as MINING CATERPILLARS. 203 we have already seen ; and we are about now to give an additional instance of the art of a species of caterpillars which select a warmer material for their tents than even the caterpillar of the clothes-moth. It may have been remarked by many who are not botanists, that the seed- catkins of the willow become, as they ripen, covered with a species of down or cotton, which, however, is too short in the fibre to be advantageously employed in onr manufac- tures. But the cateipillars, to which we have alluded, find it well adapted for their habitations. The muff-looking tent in which we find these insects a. Branch of the Willow, with seed-spikes covered Avith cotton; b. Muff Tents, made of this cotton by c, the Caterpillar. does not require much trouble to construct ; for the cater- pillar does not, like the clothes-moth caterpillar, join the willow-cotton together, fibre by fibre — it is contented with the state in which it finds it on the seed. Into this it burrows, lines the interior with a tapestry of silk, and then detaches the whole from the branch where it was growing, 204 INSECT ARCHITECTURE. and carries it about with it as a protection while it is feeding.* An inquiring friend of Reaumur having found one of these insects floating about in its muff-tent upon water, conchided that they fed upon aquatic plants ; but he was soon convinced that it had only been blown down by an accident, which must frequently happen, as willows so often hang over water. May it not be, that the buoyant materials of the tent were intended to furnish the little inhabitant with a life-boat, in which, when it chanced to be blown into the water, it might sail safely ashore and regain its native tree ? Leaf-mining Caterpillars. The process of mining between the two membranes of a leaf is carried on to more extent by minute caterpillars allied to the tent-makers above described. The tent-maker never deserts his house, except when compelled, and there- fore can only mine to about half the length of his own body ; but the miners now to be considered make the mine itself their dwelling-place, and as they eat their way, they lengthen and enlarge their galleries. A few of these mining caterpillars are the progeny of small weevils {Carcidionidce), some of two- winged flies (Diptent), but the greater number are produced from a genus of minute moths {(Ecophora, Latr.), which, when magnified, appear to be amongst the most splendid and brilliant of Nature's produc- tions, vying even with the humming-birds and diamond- beetles of the tropics in the rich metallic colours which bespangle their wings. Well may Bonnet call them " tiny miracles of nature," and regret that they are not en grand.^ There are few plants or trees whose leaves may not, at some season of the year, be found mined by these caterpillars, the track of whose progress appears on the upper surface in winding lines. Let us take one of the most common of these for an example, — that of the rose- * Keaumm-, iii. p. 130. t Bonnet, ' Contempl. do la Xatmv,' part xii. MINING CATERPILLARS. 205 leaf, produced by the caterpillar of Eay's golden-silver spot {Argyromiges Rayella? Curtis), of which we have just gathered above a dozen specimens from one rose-tree. (J-E.) It may be remarked that the winding line is black, closely resembling the tortuous course of a river on a map, — beginning like a small brook, and gradually in- creasing in breadth as it proceeds. This representation of a river exhibits, besides, a narrow, white valley on each side of it, increasing as it ^oes, till it terminates in a broad delta. The valley is the portion of the inner leaf from Leaf of the Monthly Rose {Bose Indica}, mined by Caterpillars of Argyroniiges ? which the caterpillar has eaten the pulp (parenchyma), while the river itself has been formed by the liquid ejecta- menta of the insect, the watery part becoming evaporated. In other species of miners, however, the dung is hard and diy, and consequently these only exhibit the valley without the river (see p. 207). On looking at the back of the leaf, where the winding line begins, we uniformly find the shell of the very minute egg from which the caterpillar has been hatched, and hence perceive that it digs into the leaf the moment it escapes from the egg, without wandering a hair's-breadth from the spot ; as if afraid lest the air should visit it too 206 INSECT ARCHITECTURE. roughly. The egg is, for the most part, placed upon the mid-rib of the rose-leaf, but sometimes on one of the larger nervures. When once it has got within the leaf, it seems to pursue no certain direction, sometimes working to the centre, sometimes to the circumference, sometimes to the point, and sometimes to the base, and even, occa- sionally, crossing or keeping parallel to its own previous track. The most marvellous circumstance, however, is the minuteness of its workmanship ; for though a rose-leaf is thinner than this paper, the insect finds room to mine a tunnel to live in, and plenty of food, without touching the two external membranes. Let an}'- one try with the nicest dissecting insti-uments to separate the two plates of a rose-leaf, and he will find it impossible to proceed idr without tearing one or other. The caterpillar goes still further in minute nicety ; for it may be remarked, that its track can only be seen on the upper, and not on the under surface of the leaf, proving that it eats as it pro- ceeds only half the thickness of the pulp, or that portion of it which belongs to the upper membrane of the leaf. We have found this little miner on almost every sort of rose-tree, both wild and cultivated, including the sweet- briar, in which the leaf being very small, it requires nearly the whole parenchyma to feed one catei-pillar. They seem, however, to prefer the foreign monthly rose to any of our native species, and there are few trees of this where the}^ may not be discovered. Tunnels very analogous to the preceding may be found upon the common bramble {Rabns fruticosus) ; and on the holly, early in spring, one which is in form of an irregular whitish blotch. But in the former case, the little miner seems to proceed more regularly, always, when newly hatched, making directly for the circumference, upon or near which also the mother moth deposits her eggj and winding along for half the extent of the leaf close upon the edge, following, in some cases, the very indentations formed by the terminating nervures. The bramble-leaf miner seems also to differ from that MIXING CATERPILLARS. 207 of the rose-leaf, by eating the pulp both from the tipper and under surface, at least the track is equally distinct above and below; yet this may arise from the different consistence of the leaf pulp, that in the rose being firm, while that of the bramble is soft and puffy. Leaf of the Dew-berry Bramble (Rubus ccesius'), mined by Caterpillars. On the leaves of the common primrose {Pri7nula veris), as well as on the garden variety of it, the polyanthus, one of those mining caterpillars may very frequently be found. It is, however, considerably difterent from the preceding, for there is no black trace — no river to the valley which it excavates : its ejectamenta, being small and solid, are Leaf of tlie Primrose {Primula veris), mined by a Cateri)illar. seen, when the leaf is dried, in little black points like grains of sand. This miner also seems more partial than the preceding to the mid-rib and its vicinity, in conse- quence of which its path is seldom so tortuous, and often appears at its extremity to terminate in an area, conii^ara- 208 INSECT ARCHITECTURE. tively extensive, arising from its recrossing its previous tracks. (J. E.) Swammerdam describes a mining caterpillar wliicli he found on the leaves of the alder, though it did not, like those we have just described, excavate a winding gallerj^ ; it kept upon the same spot, and formed only an irregular area. A moth was produced from this, whose upper wings, he says, " shone and glittered most gloriously with crescents of gold, silver, and brown, surrounded by borders of delicate black." Another area miner which he found on the leaves of willows, as many as seventeen on one leaf, producing what appeared to be rusty spots, was metamor- phosed into a very minute weevil {Curculio Ehinoc). He says he has been informed that, in warm climates, worms an inch long are found in leaves, and adds, wdth great simplicity, " on these many fine experiments might have been made, if the inhabitants had not laboured under the cursed thirst of gold." * The vine-leaf miner, when about to construct its cocoon, cuts, from the termination of its gallery, two pieces of the membrane of the leaf, deprived of their pulp, in a similar manner to the tent-makers described above, uniting them and lining them wath silk. This she carries to some distance before she lays herself up to undergo her change. Her mode of walking under her burthen is peculiar, for, not contented with the security of a single thread of silk, she forms, as Bonnet says, " little mountains (monticules) of silk, from distance to distance, and seizing one of these with her teeth, drags herself forward, and makes it a scaffolding from which she can build another." | Some of the miners, however, do not leave their galleries, but undergo their transformations there, taking the precaution to mine a cell, not in the upper, but in the under surface ; others only shift to another portion of the leaf. * Swammerd., ' Book of Natiu-e,' vol. ii. p. 84. t ' Contempl. de la Nature,' part xii. p. 197. BARK-MINING CATERPILLARS. 209 Social Leaf-Miners. The preceding descriptions apply to caterpillars who construct their mines in solitude, there being seldom more than one on a leaf or leaflet, unless when two mother-flies happen to lay their eggs on the same leaf; but there are others, such as the miners of the leaves of the henbane {Hyos- cyamus niger), which excavate a common area in concert — from four to eight forming a colony. These are very like flesh-maggots, being larger than the common miners ; the leaves of this plant, from being thick and jnicy, giving them space to work and plenty to eat. Most of the solitary leaf-miners either cannot or will not construct a new mine, if ejected by an experimenter from the old, as we have frequently proved ; but this is not the case with the social miners of the henbane-leaf. Bonnet ejected one of these, and watched it with his glass till it commenced a new tunnel, which it also enlarged with great expedition ; and in order to verify the assertion of Eeaumur, that they neither endeavour nor fear to meet one another, he introduced a second. Keither of them mani- fested any knowledge of the other's contiguity, but both worked hard at the gallery, as did a third and a fourth which he afterwards introduced ; for though they seemed uneasy, they never attacked one another, as the solitary ones often do when they meet.* Bark-mining Caterpillars. A very different order of mining caterpillars are the progeny of various beetles, which excavate their galleries in the soft inner bark of trees, or between it and the young wood (alburnum). Some of these, though small, commit extensive ravages, as may readily be conceived when we are told that as many as eighty thousand are occasionally foinid on one tree. In 1783 the trees thus destroyed by the printer-beetle (Tomicus typographus, Latr.), so called from its tracks resembling letters, amounted to above a million and a half in the Hartz forest. It appears there * Bonnet, ' Observ. sur les Insectes/ vol, ii. p. 425. P 210 INSECT ARCHITECTURE. periodically, and confines its ravages to tlie fir. This insect is said to have been found in the neighbourhood of London. On taking off the bark of decaying poplars and willows, we have frequently met with the tracks of a miner of this order, extending in tortuous pathways, about a quarter of an inch broad, for several feet and even yards in length. The excavation is not circular, but a compressed oval, and crammed throughout with a dark-coloured substance like sawdust — the excrement no doubt of the little miner, who is thereby protected from the attacks of Staphylimdce, and other predaceous insects, from behind. But though we have found a great number of these subcortical tracks, we have never discovered one of the miners, though they are very probably the grubs of the pretty musk-beetle (Cerambyx 7noschatus)y which are so abundant in the neighbourhood of the trees in question, that the very air in summer is perfumed with their odour. (J. R.) Another Capricorn beetle of this family is no less de- Capricorn Beetle (Cerambyx Lamia ampulator), rounding off the bark of a tree. structive to bark in its perfect state than the above are when, grubs, as from its habit of eating round a tree, it cuts the course of the returning sap, and destroys it. ( 211 ) CHAPTER XIII. STRUCTURES OF GRASSHOPPERS, CRICKETS, AND BEETLES. Grasshoppers, locusts, crickets, and beetles are, in many respects, no less interesting than the insects whose archi- tectural proceedings we have already detailed. They do not, indeed, build any edifice for the accommodation of them- selves or their progeny ; but most, if not all of them, exca- vate retreats in walls or in the ground. The house-cricket (Acheta domestica) is well known for its habit of picking out the mortar of ovens and kitchen fire- jolaces, where it not only enjoys warmth, but can procure abundance of food. It is usually supposed that it feeds on bread. M. Latreille says it only eats insects, and .'it cer- tainly thrives well in houses infested by the cockroach ; but we have also known it eat and destroy lamb's-wool stockings, and other woollen stuffs, hung near a fire to dry. It is evidently not fond of hard labour, but prefers those places where the mortar is already loosened, or at least is new, soft, and easily scooped out ; and in this way it will dig covert ways from room to room. In summer, crickets often make excursions from the house to the neighbouring fields, and dwell in the crevices of rubbish, or the cracks made in the ground by dry weather, where they chirp as merrily as in the snuggest chimney comer. Whether they ever dig retreats in such circumstances we have not ascertained ; though it is not improbable they may do so for the purpose of making nests. M. Bory St. Vincent tells us that the Spaniards are so fond of crickets that they keep them in cages like singing birds.* The Molk-Cricket. The insect, called, from its similarity of habits to the mole, the mole-cricket {Gryllotalpa vulgaris, Latr.) is but * Diet. Classique d'Hist. Nat. Art. Grillon. 212 INSECT ARCHITECTURE. too well known in gardens, corn-fields, and the moist banks of rivers and ponds, in some parts of England, such as Wilt- shire and Hampshire, though it is comparatively rare or unknown in others. It burrows in the groifnd, and forms extensive galleries similar to those of the mole, though smaller ; and these may always be recognised by a slightly elevated ridge of mould : for the insect does not throw up the earth in hillocks like the mole, but gradually, as it digs along, in the manner of the field-mouse. In this way it commits great ravages, in hotbeds and in gardens, upon peas, young cabbages, and other vegetables, the roots of which it is said to devour. It is not improbable, we think, that, like its congener, the house-cricket, it may also prey upon undergTound insects, and undermine the plants to get at them, as the mole has been proved to do. Mr. Gould, indeed, fed a mole-cricket for several months upon ants. The structure of the mole-cricket's arms and hands (if we The Mole-Cricket, with a separate outline of one of its hands. may call them so) is admirably adapted for these operations, being both very strong, and moved by a peculiar apparatus of muscles. The breast is formed of a thick, hard, horny substance, which is further strengthened within by a double framework of strong gristle, in front of the extremi- MOLE-CRICKET. 213 ties of which the shoulder-blades of the arms are firmly jointed: a structure evidently intended to prevent the breast from being injured by the powerful action of the muscles of the arms in digging. The arms themselves are strong and broad, and the hand is furnished with four large sharp claws, pointed somewhat obliquely outwards, this being the direction in which it digs, throwing the earth on each side of its course. So strongly indeed does it throw out its arms, that we find it can thus easily support its own weight when held between the finger and thumb, as we have tried upon half-a-dozen of the living insects now in our possession. The nest which the female constructs for her eggs, in the beginning of May, is well worthy of attention. The Rev. pp^^ffc^,---- Nest ot the Mole-Cricket. Mr. AVhite, of Selborne, tells us that a gardener, at a house where he was on a visit, while mowing grass by the side of a canal, chanced to strike his scythe too deep, and pared off a large piece of turf, laying open to view an interesting scene of domestic economy. There was a prett}^ chamber dug in the clay, of the form and about the dimensions it would have had if moulded by an egg, the w^alls being neatly smoothed and polished. In this little cell were deposited about a hundred eggs, of the size and form of caraway comfits, and of a dull tarnished white colour. The eggs were not ver}'- deep, but just under a little heap of fresh mould, and within the influence of the sun's heat.* The dull tarnished white colour, towever, scarcely agrees * Natural History of Sell:)orne, ii. 82. 21-1: IXSECT ARCHITECTURE. with a parcel of these eggs now before us, which are trans- lucent, gelatinous, and greenish. Like the eggs and young of other insects, however, those of the mole-cricket are exposed to depredation, and par- ticularly to the ravages of a black beetle which burrows in similar localities. The mother insect, accordingly, does not think her nest secure till she has defended it, like a fortified town, with labyrinths, intrenchments, ramparts, and covert ways. In some part of these outworks she stations herself as an advanced guard, and when the beetle ventures within her circumvallations, she pounces upon him and kills him. The Field-Cricket. Another insect of this family, the field-cricket (Acheta campestris), also forms burrows in the ground, in which it lodges all day, and comes out chiefly about sunset to pipe its evening song. It is so very shy and cautious, however, that it is by no means easy to discover either the insect or its burrow. " The children in France amuse themselves with hunting after the field-cricket ; they put into its hole an ant fastened by a long hair, and as they draw it out the cricket does not fail to pursue it, and issue from its retreat. Pliny informs us it might be captured in a much more expeditious and easy manner. If, for instance, a small and slender piece of stick were to be thrust into the burrow, the insect, he says, would immediately get upon it for the purpose of demanding the occasion of the intrusion : whence arose the proverb stultior grillo (more foolish than a cricket), applied to one who, upon light grounds, provokes his enemy, and falls into the snares which might have been laid to entrap him."* The Eev. Mr. White, who attentively studied their habits and manners, at first made an attempt to dig them out with a spade, but without any great success; for either the bottom of the hole was inaccessible, from its terminating under a large stone, or else in breaking up the ground, the poor creature was inadvertently squeezed to death. Out of one thus bruised, a great number of eggs were taken, which * Entomologie, par R. A. E. ISmo., raris, 182G, p. 168. FIELD-CRICKET. 215 were long and narrow, of a yellow colour, and covered with a very tough skin. More gentle means were then used, and these proved successful. A pliant stalk of grass, gently insinuated into the caverns, will probe their windings to the bottom, and bring out the inhabitant ; and thus the humane inquirer may gratify his curiosity without injuring the object of it. When the males meet, the}^ sometimes fight very fiercely, as Mr. White found b}^ some that he put into the crevices of a dry stone wall, where he wished to have them settle. For though they seemed distressed by being taken out of their knowledge, yet the first that got possession of the chinks seized on all the others that were obtruded upon him with his large row of serrated fangs. With their strong jaws, toothed like the shears of a lobster's claws, they perforate and round their curious regular cells, having no fore claws to dig with, like the mole-cricket. When taken into the hand, they never attempt to defend themselves, though armed with such formidable Aveapons Of such herbs as grow about the mouths of their burrows they eat indiscri- minately, and never in the day-time seem to stir more than two or three inches from home. Sitting in the entrance of their caverns, they chirp all night as well as day, from the middle of the month of IMay to the middle of July. In hot weather, when they are most vigorous, they make the hills echo ; and, in the more still hours of darkness, may be heard to a very considerable distance. " Not many sum- mers ago," says Mr. White, " I endeavoured to transplant a colony of these insects to tlie terrace in my garden, by boring deep holes in the sloping turf. The new inhabitants stayed some time, and fed and saing ; but they wandered away by degrees, and were heard at a greater distance every morning ; so it appears that on this emergency they made use of their wings in attempting to return to the spot from which they were taken."* The manner in which these insects lay their eggs is represented in the following figure ; which is that of an insect nearly allied to the crickets, though of a different genus. * Natural History of Selborno. 216 rXSECT ARCHITECTURE. Aci-ida verrucivora depositing her eggs. Tlie usual position of tlie ovipositor is represented by dots. A more laborious task is performed by an insect by no means uncommon in Britain, the Burying Beetle (^Necro- pliorus vespiUo), which may be easily recognised by its longisli body, of a black colour, with two broad and irregularly indented bands of yellowish brown. A foreign naturalist, M. Gleditsch, gives a very interesting account of its in- dustry. He had " often remarked that dead moles, when laid upon the ground, especially if upon loose earth, were almost sure to disappear in the course of two or three days, often of twelve hours. To ascertain the cause, he placed a mole upon one of the beds in his garden. It had vanished by the third morning ; and on digging where it had been laid, he found it buried to the depth of three inches, and under it four beetles, which seemed to have been the agents in this singular inhumation. Not perceiving anything par- ticular in the mole, he buried it again ; and on examining it at the end of six days, he found it swarming with maggots, apparently the issue of the beetles, which M. Gleditsch now naturally concluded had buried the carcass for the food of BURYING-BEETLE. 217 their future yonng. To determine these points more clearty, he put four of these insects into a glass vessel, half filled with earth and properly secured, and upon the surface of the earth two frogs. In less than twelve hours one of the frogs was interred by two of the beetles ; the other two ran about the whole day, as if busied in measuring the dimen- sions of the remaining corpse, which on the third day was also found buried. He then introduced a dead linnet. A pair of the beetles were soon engaged upon the bird. They began their operations by pushing out the earth from under' the body, so as to form a cavity for its reception ; and it was curious to see the efforts which the beetles made, by dragging at the feathers of the bird from below, to pull it into its grave. The male, having driven the female away, continu-ed the work alone for five hours. He lifted up the bird, changed its place, turned it and arranged it in the grave, and from time to time came out of the hole, mounted upon it, and trod it under foot, and then retired below, and pulled it down. At length, apparently wearied with this uninterrupted labour, it came forth, and leaned its head upon the earth beside the bird without the smallest motion, as if to rest itself, for a full hour, when it again crept under the earth. The next day, in the morning, the bird was an inch and a half under ground, and the trench remained open the whole day, the corpse seeming as if laid out upon a bier, surrounded with a rampart of mould. In the evening it had sunk half an inch lower, and in another day the work was completed, and the bird covered. M. Gleditsch con- tinued to add other small dead animals, which were all sooner or later buried; and the result of his experiment was, that in fifty days four beetles had interred, in the very small space of earth allotted to them, twelve carcasses, viz., four frogs, three small birds, two fishes, one mole, and two grasshoppers, besides the entrails of a fish, and two morsels of the lungs of an ox. In another experiment, a single beetle buried a mole forty times its own bulk and weight in two days."* * Act. Acad. Berolin. 1752, et Gleditsch, Pliys. Botan,, quoted by Kirby and Spence, ii. 353. ^ ' 218 IXSECT ARCHITECTURE. In the summer of 1826, we found on Putney Heath, in Surrey, four of these beetles, hard at work in burj-ing a dead crow, precisely in the manner described by M. Gle- ditsch. (J. R.) Dung-Beetle. A still more common British insect, the Dorr, Clock, or Dung-Beetle (^Geotrupes stercorarias), uses different materials for burying along with its eggs. " It digs," to use the 'words of Kirby and Spence, "a deep cylindrical hole, and carrying down a mass of the dung to the bottom, in it deposits its eggs. And many of the species of the genus Ateuchus roll together wet dung into round pellets, deposit an egg in the midst of each, and when dry push them back- wards, by their hind feet, to holes of the surprising depth of three feet, which they have previously dug for their re- ception, and which are often several yards distant. The attention of these insects to their eggs is so remarkable, that it was observed in the earliest ages, and is mentioned by ancient writers, but with the addition of many fables, as that they were all of the male sex ; that they became young again every year ; and that they rolled the pellets containing their eggs from sunrise to sunset every day, for twenty-eight daj^s, without intermission."* " We frequently notice in our evening walks," says Mr. Knapp, " the murmuring passage, and are often stricken by the heedless flight of the great dorr-beetle (Geotnipes sterco- rarius), clocks, as the boj^s call them. But this evening my attention was called to them in particular, b}^ the constant passing of such a number as to constitute something like a little stream ; and I was led to search into the object of their direct flight, as in general it is irregular and seem- ingly inquisitive. I soon foimd that they dropped on some recent nuisance : but what powers of perception must these creatures possess, drawn from all distances and directions by the very little fetor which, in such a calm evening, could be difi'used around, and by what inconceivable means * Mouftt, 153. Kirby ;md Spence, ii. 350. DUNG-BEETLE. 219 could odours reach this beetle in such a manner as to rouse so inert an insect into action ! But it is appointed one of the great scavengers of the earth, and marvellously endowed with 230wers of sensation, and means of effecting this pur- pose of its being. Exquisitely fabricated as it is to receive impressions, yet probably it is not more highly gifted than any of the other innumerable creatures that wing their way around us, or creep about our paths, though by this one perceptible faculty, thus ' dimly seen,' it excites our wonder and surprise. How wondrous then the whole ! " The perfect cleanliness of these creatures is a very notable circumstance, when we consider that nearly their whole lives are passed in burrowing in the earth, and re- moving nuisances ; yet such is the admirable polish of their coating and limbs, that we very seldom find any soil ad- hering to them. The meloe, and some of the scarabaei, upon first emerging from their winter's retreat, are com- monly found with earth clinging to them ; but the removal of this is one of the first operations of the creature ; and all the beetle race, the chief occupation of which is crawling about the soil, and such dirty employs, are, notwithstanding, remarkable for the glossiness of their covering, and freedom from defilements of any kind. But purity of vesture seems to be a principal precept of nature, and observable through- out creation. Fishes, from the nature of the element in which they reside, can contract but little impurity. Birds are unceasingly attentive to neatness and lustration of their plumage. All the slug race, though covered with slimy matter calculated to collect extraneous things, and reptiles, are perfectly free from soil. The fur and hair of beasts, in a state of liberty and health, is never filthy or sullied with dirt. Some birds roll themselves in dust, and, occasionally, particular beasts cover themselves with mire ; but this is not from any liking or inclination for such things, but to free themselves from annoyances, or to prevent the bites of insects. Whether birds in preening, and beasts in dressing themselves, be directed by any instinctive faculty, we know not ; but they evidently derive pleasure from the operation, and thus this feeling of enjoyment, even if the sole motive, 220 INSECT ARCHITECTURE. becomes to them an essential source of comfort and of health."* The rose or green chafer (^Cetonia aiirata), which is one of our prettiest native insects, is one of the burrowers, and, for the purpose of depositing her eggs, digs, about the middle of June, into soft light ground. When she is seen at this operation, with her broad and delicate wings folded up in their shining green cases, speckled with white, it could hardly be imagined that she had but just descended from the air, or dropped down from some neighbouring rose. The proceedings of the Tumble-Dung Beetle of America (Scarahoeus pihdanas, Linn.) are described in a very interest- ing manner by Catesby, in his ' Carolina.' " I have," says he, "attentively admired their industry, and mutual assist- ing of each other in rolling their globular balls from the place where they made them to that of their interment, which is usually the distance of some yards, more or less. This they perform breech foremost, by raising their hind parts, and forcing along the ball with their hind feet. Two or three of them are sometimes engaged in trundling one ball, which, from meeting with impediments on account of the unevenness of the ground, is sometimes deserted by them. It is, however, attempted by others with success, unless it happens to roll into some deep hollow or chink, where they are constrained to leave it ; but they continue their work by rolling off the next ball that comes in their way. None of them seem to know their own balls, but an equal care for the whole appears to affect all the community. They form these pellets while the dung remains moist, and leave them to harden in the sun before they attempt to roll them. In their moving of them from place to place, both they and the balls may frequently be seen tumbling about the little eminences that are in their way. The}^ are not, however, easily discouraged; and, by repeating their attempts, usually surmount the difficulties." He further informs us that they " find out their sub- * Jom-ual of a Xaturali.st, p. oil. TUMBLE-DUNG-BEETLE. 221 sistence by the excellency of their noses, which direct them in their flight to newly-fallen climg, on which they immediately go to work, tempering it with a proper mixture of earth. So intent are they always upon their employ- ment, that, though handled or otherwise interrupted, they are not to be deterred, but immediately, on being freed, persist in their work without any apprehension of danger. They are said to be so exceedingly strong and active as to move about, with the greatest ease, things that are many times their own weight. Dr. Brichell was supping one evening in a planter's house of North Carolina, when two of them were conveyed, without his knowledge, under the candlestick. A few blows were struck on the table, and, to his great surprise, the candlesticks -began to move about, apparently without any agency ; and his surprise was not much lessened when, on taking one of them up, he dis- covered that it was only a chafer that moved." We have often found the necklace-beetle (Carahus monilis) inhabiting a chamber dug out in the earth of a garden, just sufficient to contain its body, and carefully smoothed and polished. From the form of this little nest, it would seem as if it were constructed, not by digging out the earth and removing it, but chiefly by the insect pushing its body forcibly against the walls. The beetles which we have found nestling in this manner have been all males; and therefore it cannot be intended for a breeding-cell; for male insects are never, we believe, sufficiently generous to their mates to assist them in such labours. The beetle in question appears to be partial to celery trenches (J. E.) ; probably from the loose earth of which they are composed yielding, without much difficulty, to the pressure of its body. ( 222 ) CHAPTER XIV. ARCHITECTURE OF ANTS. — MASOX-ANTS. All the species of ants are social. There are none soli- tary, as is the case with bees and wasps. They are all more or less skilful in architecture, some employing ma- sonry, and others being carpenters, wood-carvers, and miners. They consequently afford much that is interest- ing to naturalists who observe their operations. The genuine history of ants has only been recently investi- gated, first by Gould in 1747, and subsequently by Linnoeus, Be Geer, Huber, and Latreille. Previous to that time their real industry, and their imagined foresight, were held up as moral lessons, without any great accuracy of observation; and it is probable that, even now, the mixture of truth and error in Addison's delightful papers in the Guardian (Nos. 156, 157), maybe more generally attractive than the minute relation of careful naturalists. Gould disproved, most satisfactorily, the ancient fable of ants storing up corn for winter provision, no species of ants ever eating grain, or feeding in the winter upon anything. It is to Huber the younger, however, that we are chiefly indebted for our knowledge of the habits and economy of ants ; and to Latreille for a closer distinction of the species. Some of the more interesting species, whose singular economy is described by the younger Huber, have not been hitherto found in this country. We shall, however, discover matter of very considerable interest in those which are indigenous ; and as our principal object is to excite inquiry and observation with regard to those insects which may be easily watched in our own gardens and fields, we shall chiefly confine ourselves to the ants of these islands. We shall begin with the labours of those native ants which may be called earth-masons, from their MASOX-ANTS. 223 digging ill the ground, and forming structures with pellets of moistened loam, clay, or sand. Mason-Ants. We have used, in the preceding pages, the terms mason- bees and mason-wasps, for insects which build their nests of earthy materials. On the same principle, we have followed the ingenious M. Huber the younger, in employing the term mason-ants for those whose nests on the exterior appear to be hillocks of earth, without the admixture of other materials, whilst in the interior they present a series of labyrinths, lodges, vaults, and galleries constructed with considerable skill. Of these mason-ants, as of the mason- wasps and bees already described, there are several species, differing from one another in their skill in the art of architecture. One of the most common of the ant-masons is the turf- ant (Formica ccespitum, Latr.), which is very small and of a blackish-brown colour. Its architecture is not upon quite so extensive a scale as some of the others ; but, though slight, it is very ingenious. Sometimes they make choice of the shelter of a flat stone or other covering, beneath which they hollow out chambers and communicating galleries ; at other times they are contented with the open ground ; but most commonly they select a tuft of grass or other herbage, the stems of which serve for columns to their earthen walls. We had a small colony of these ants accidentally esta- blished in a flower-pot, in which we were rearing some young plants of the tiger-lily (Lilium figrinum'), the stems of which being stronger than the grass where they usually build, enabled them to rear their edifice higher, and also to make it more secure, than they otherwise might. It was wholly formed of small grains of moist earth, piled up between the stems of the lily without any apparent cement ; indeed it has been ascertained by Huber, as we shall after- wards see, that they use no cement beside water. This is not always to be procured, as they depend altogether on rains and dew ; but they possess the art of joining grains 224 IXSECT ARCHITECTURE. of dry sand so as to support one another, on some similar principle, no doubt, to that of the arch. The nest which our turf-ants constructed in the flower- pot was externally of an imperfect square form, in con- sequence of its situation ; for they usually prefer a circular plan. The principal chambers were placed under the arches, and, when inspected, contained a pile of cocoons and pupee. Beneath those upper chambers there Avere others dug out deeper down, in which were also a numerous collection of eggs and cocoons in various stages of advance- ment. (J. E.) Mr. Knapp describes a still more curious structure of another species of ant common in this country : — " One year," says he, " on the third of March, my labourer being employed in cutting up ant-hills, or tumps as we call them, exposed to view multitudes of the yellow species (^Formica fiam) in their winter's retirement. They were collected in numbers in little cells and compartments, communicating with others by means of narrow passages. In many of the cells they had deposited their larvae, which they were surrounding and attending, but not brood- ing over or covering. Being disturbed by our rude opera- tions, they removed them from our sight to more hidden compartments. The larvas were small. Some of these ant-hills contained multitudes of the young of the wood- louse {Oniscus armadillo), inhabiting with perfect familiarity the same compartments as the ants, crawling about with great activity v/ith them, and perfectly domesticated with each other. They were small and white ; but the constant vibration of their antennae, and the alacrity of their motions, manifested a healthy vigour. The ants were in a torpid state ; but on being removed into a temperate room, they assumed much of their summer's animation. How these creatures are supported during the winter season it is difficult to comprehend ; as in no one instance could we perceive any store or provision made for the supply of their wants. The minute size of the larvae manifested that they had been recently deposited ; and consequently that their parents had not remained during winter in a dormant state, MASON-ANTS. 225 and thus free from the calls of hunger. The preceding month of Februarj^ and part of January, had been re- markably severe; the frost had penetrated deep into the earth, and long held it frozen ; the ants were in many cases not more than four inches beneath the surface, and must have been enclosed in a mass of frozen soil for a long period ; yet they, their young, and the onisci, vi^ere per- fectly uninjured by it : affording another proof of the fallacy of the commonly received opinion, that cold is universally destructive to insect life." * The earth employed by mason-ants is usually moist clay, either dug from the interior parts of their city, or moist- ened by rain. The mining-ants and the ash-coloured (Formica fusca) employ earth which is probably not selected with so much care, for it forms a much coarser mortar than what we see used in the structure of the yellow ants (F. flava) and the brown ants (F. hruanea). We have never observed them bringing their building materials of this kind from a distance, like the mason-bees and like the wood or hill ant (^F. rufa) ; but they take care, before they fix upon a locality, that it shall produce them all that they require. We are indebted to Huber the younger for the most complete account which has hitherto been given of these operations, of which details we shall make free use. " To form," says this shrewd observer, " a correct judg- ment of the interior arrangement or distribution of an ant- hill, it is necessary to select such as have not been acci- dentally spoiled, or whose form has not been too much altered by local circumstances ; a slight attention will then suffice to show that the habitations of the different species are not all constructed after the same sj'stem. Thus, the hillock raised by the ash-coloured ants will always present thick walls, fabricated with coarse earth, well-marked stories, and large chambers, with vaulted ceilings, resting upon a solid base. We never observe roads, or galleries, properly so called, but large passages, of an oval form, and all around considerable cavities and * Journal of a Natiu-alist, p. 304. 226 IXSECT ARCHITECTURE. extensive embankments of earth. We further notice, that the little architects observe a certain proportion between the large arched ceilings and the pillars that are to support them. " The brown ant (^Formica hrunnea), one of the smallest of the ants, is particularly remarkable for the extreme finish of its work. Its body is of a reddish shining brown, its head a little deeper, and the antennae and feet a little lighter in colour. The abdomen is of an obscure brown, the scale narrow, of a square form, and slightly scolloped. The body is one line and two-fifths in length."* " This ant, one of the most industrious of its tribe, forms its nest of stories four or five lines in height. The partitions are not more than half a line in thickness : and the substance of which they are composed is so finely grained, that the inner walls present one smooth unbroken surface. These stories are not horizontal ; they follow the slope of the ant-hill, and lie one upon another to the ground-floor, which communicates with the subterranean lodges. They are not always, however, arranged with the same regularit}', for these ants do not follow an invariable plan ; it appears, on the contrary, that nature has allowed them a certain latitude in this respect, and that they can, according to circumstances, modif}^ them to their wish ; but, however fantastical their habitations may appear, we always observe they have been formed by concentrical stories. On examining each story separately, we observe a number of cavities or halls, lodges of narrower dimensions, and long galleries, which serve for general communication. The arched ceilings covering the most spacious places are supported either by little columns, slender walls, or by regular buttresses. We also notice chambers, that have but one entrance, communicating with the lower story, and large open spaces, serving as a kind of cross-road (carrefour), in which all the streets terminate. " Such is the manner in which the habitations of these ants are constructed. Upon opening them, we commonly * A line is the twelfth part of the old French inch. See Companion to the Almanac for 1830, p. 114. MASON- ANTS. • 227 find the apartments, as well as the large open spaces, filled with adult ants ; and always observed their pupae collected in the apartments more or less near the surface. This, however, seems regulated b}^ the hour of the day, and the temperature : for in this respect these ants are endowed with great sensibility, and know the degree of heat best adapted for their young. The ant-hill contains, sometimes, more than twenty stories in its upper portion, and at least as many under the surface of the ground. By this arrangement the ants are enabled, with the greatest facility, to regulate the heat. When a too burning sun over-heats their upper apartments, ihey withdraw their little ones to the bottom of the ant-hill. The ground-floor becoming, in its turn, uninhabitable during the rain}^ season, the ants of this species transport what most interests them to the higher stories ; and it is there we find them more usually assembled, with their eggs and pupae, when the subterranean apartments are submerged." * Ants have a great dislike to water, when it exceeds that of a light shower to moisten their building materials. One species, mentioned by Azara as indigenous to South America, instinctively builds a nest from three to six feet high,t to provide against the inundations during the rainy season. Even this, however, does not always save them from submersion ; and, when that occurs, they are compelled, in order to prevent themselves from being swept away, to form a group somewhat similar to the curtain of the wax-workers of hive-bees (see p. 99). The ants constituting the basis of this group, lay hold of some shrub for security, while their companions hold on by them ; and thus the whole colony, forming an animated raft, floats on the surface of the water till the inundation (which seldom continues longer than a day or two) subsides. V\e confess, however, that we are somewhat sceptical respecting this story, notwithstanding the very high character of the Spanish naturalist. * M. P. Huber on Ants, p. 20. t Stedman's Simnam, vol. i., p. IGO. 228 INSECT ARCHITECTURE. It is usual with architectural insects to employ some animal secretion, by way of mortar or size, to temper the materials with which they work ; but the whole economy of ants is so different, that it would be wrong to infer from analogy a similarity in this respect, though the exquisite polish and extreme delicacy of finish in their structures, lead, naturally, to such a conclusion. M. P. Huber, in order to resolve this question, at first thought of subjecting the materials of the walls to chemical analysis, but wisely (as we think) abandoned it for the surer method of observation. The details which he has given, as the result of his researches, are exceedingly curious and in- structive. He began by observing an ant-hill till he could perceive some change in its form. " The inhabitants," says he, " of that which I selected, kept within during the day, or only went out by subter- ranean galleries which opened at some feet distance in the meadow. There were, however, two or three small openings on the surface of the nest ; but I saw none of the labourers pass out this way, on account of their being too much exposed to the sun, which these insects greatly dread. This ant-hill, which had a round form, rose in the grass, at the border of a path, and had sustained no injury. I soon perceived that the freshness of the air and the dew invited the ants to walk over the surface of their nest ; they began making new apertures ; several ants might be seen arriving at the same time, thrusting their heads from the entrances, moving about their antennee, and at length adventuring forth to visit the environs. " This brought to my recollection a singular opinion of the ancients. They believed that ants were occupied in their architectural labours during the night, when the moon was at its full."* M. Latreille discovered a sj^ecies of ants which were, so far as he could ascertain, completely blind,t and of course it would be immaterial to them whether they worked by night or during the day. All observers indeed agree that * M. P. Huber on Ants, p. 23. t Latreille Hist. Nat. des Fourmis. MASON-ANTS. 229 ants labour in the night, and a French naturalist is there- fore of opinion that they never sleep, — a circumstance which is well ascertained with respect to other animals, such as the shark, which will track a ship in full sail for weeks together.* The ingenious historian of English ants, Gould, says they never intermit their labours by night or by day, except when compelled by excessive rains. It is probable the ancients were mistaken in asserting that they only work when the moon shines ;-f for, like bees, they seem to find no difficult}^ in building in the dark, their subterranean apartments being as well finished as the upper stories of their buildings. But to proceed with the narra- tive of M. P. Huber. " Having thus noticed the movements of these insects during the night, I found they were almost always abroad and engaged about the dome of their habitation after sunset. This was directly the reverse of what I had observed in the conduct of the wood-ants (^F. rufa), who only go out during the day, and close their doors in the evening, The contrast was still more remarkable than I had previously supposed ; for upon visiting the brown ants some days after, during a gentle rain, I saw all their architectural talents in full play. " As soon as the rain commenced, they left in great numbers their subterranean residence, re-entered it almost immediately, and then returned, bearing between their teeth pellets of earth, which they deposited on the roof of their nest. I could not at first conceive what this was meant for, but at length I saw little walls start up on all sides with spaces left between them. In several places, columns, ranged at regular distances, announced halls, lodges, and passages, which the ants proposed establishing ; in a word, it was the rough beginning of a new story. " I watched with a considerable degree of interest the * Dr. Clegliorn, Thesis de Somiio. t Aristotle Hist. Animal, ix. '38. Pliny says, " Operantiir et noctu plena luna ; eadem intciiimio cessant," i e., They work in the night at full moon, but they leave oif between moon and moon. It is the latter that we think doubtful. 230 INSECT ARCHITECTURE. most trifling movements of my masons, and foimd they did not work after the manner of wasps and humble-bees, when occupied in constructing a covering to their nest. The latter sit, as it were, astride on the border or margin of the covering, and take it between their teeth to model and attenuate it according to their wish. The wax of which it is composed, and the paper Avhich the wasp employs, moistened by some kind of glue, are admirably adapted for this purpose, but the earth of which the ants make use, from its often possessing little tenacity, must be worked up after some other manner. " Each ant, then, carried between its teeth the pellet of earth it had formed by scraping with the end of its man- dibles the bottom of its abode, a circumstance which I have frequently witnessed in open day. This little mass of earth, being composed of particles but just united, could be readily kneaded and moulded as the ants wished ; thus when they had applied it to the spot where they had to rest, they divided and pressed against it with their teeth, so as to fill up the little inequalities of their wall. The antennae followed all their movements, passing over each particle of earth as soon as it was placed in its proper position. The whole was then rendered more compact by pressing it lightly with the fore-feet. This work went on remarkably fast. After having traced out the plan of their masonry, in laying here and there foundations for the pillars and partitions they were about to erect, they raised them gradually higher, by adding fresh materials. It often happened that two little walls, which were to form a gallery, were raised opposite, and at a slight distance from each other. When they had attained the height of four or five lines, the ants busied themselves in covering in the space left betvv^een them by a vaulted ceiling. " As if they judged all their partitions of sufficient elevation, they then quitted their labours in the upper part of the building ; they affixed to the interior and upper part of each wall fragments of moistened earth, in an almost horizontal direction, and in such a way as to form a ledge, which, by extension, would be made to join that MASOX-ANTS. 231 coming from the opposite wall. These ledges were about half a line in thickness ; and the breadth of the galleries was, for the most part, about a quarter of an inch . On one side several vertical partitions were seen to form the scaffolding of a lodge, which communicated with several corridors, by apertures formed in the masonrj^ ; on another, a regulary-formed hall was constructed, the vaulted ceiling of which was sustained by numerous pillars ; further off, again, might be recognised the rudiments of one of those cross roads of which I have before spoken, and in which several avenues terminate. These parts of the ant-hill were the most spacious : the ants, however, did not appear embarrassed in constructing the ceiling to cover them iu, although they were often more than two inches in breadth. " In the upper part of the angles formed by the different walls, they laid the first foundations of this ceiling, and from the top of each pillar, as from so many centres, a layer of earth, horizontal and slightly convex, was carried forward to meet the several portions coming from different points of the large public thoroughfare. " I sometimes, however, laboured under an apprehension that the building could not possibly resist its own weight, and that such extensive ceilings, sustained only by a few pillars, would fall into ruin from the rain which continually dropped upon them ; but I was quickly convinced of their stability, from observing that the earth brought by these insects adhered at all points, on the slightest contact ; and that the rain, so far from lessening the cohesion of its particles, appeared even to increase it. Thus, instead of injuring the building, it even contributed to render it still more secure. " These particles of moistened earth, which are onl}- held together by juxtaposition, require a fall of rain to cement them more closely, and thus varnish over, as it were, those places where the walls and galleries remain uncovered. All inequalities in the masonry then disappear. The upper part of these stories, formed of several pieces brought together, presents but one single layer of compact 232 INSECT ARCHITECTURE. earth. They require for their complete consolidation nothing but the heat of the sun. It sometimes, however happens that a violent rain will destroy the apartments especially should they be but slightly arched; but under these circumstances the ants reconstruct them with won- derful patience. " These different labours were carried on at the same time, and were so closely followed up in the different quarters, that the ant-hill received an additional story in the course of seven or eight hours. All the vaulted ceilings being formed upon a regular plan, and at equal distances from one wall to the other, constituted, when finished, but one single roof. Scarcely had the ants finished one story than they began to construct another ; but they had not time to finish it — the rain ceasing before the ceiling was fully completed. They still, however, continued their work for a few hours, taking advantage of the humidity of the earth ; but a keen north wind soon sprung up, and hastily dried the collected fragments, which, no longer {)0ssessing the same adherence, readily fell into powder. The ants, finding their efforts ineffectual, were at length discouraged, and abandoned their employment ; but what was my astonishment when I saw them destroy all the apartments that were yet uncovered, scattering here and there over the last story the materials of which they had been composed ! These facts incontestably prove that they employ neither gum, nor any kind of cement, to bind together the several substances of their nest ; but in place of this avail themselves of the rain, to work or knead the earth, leaving the sun and wind to dry and consolidate it."* Dr. Johnson of Bristol observed very similar proceed- ings in the case of a colony of red ants (^Myrmica I'uhra?), the roof of whose nest was formed by a flat stone. During dry weather, a portion of the side walls fell in ; but the rubbish was quickly removed, though no repairs were attempted till a shower of rain enabled them to work. As soon as this occurred, they worked with extraordinary * ]M. P. Hul3er on Ants, p. 31. MASON-ANTS. 233 rapidity, and in a short time the whole of the fallen parts were rebuilt, and rendered as smooth as if polished with a trowel. When a gardener wishes to water a plot of ground where he has sown seeds that require nice management, he dips a strong brush into water, and passes his hand backwards and forwards over the hairs for the purpose of producing a fine artificial shower. Huber successfully adopted the same method to excite his ants to recom- mence their labours, which had been interrupted for want of moisture. But sometimes, when they deem it unadvi- sable to wait for rain, they dig down (as we remarked to be the practice of the mason-bees) till they arrive at earth sufficiently moist for their purpose. They do not, however, like these bees, merely dig for materials ; for they use the excavations for apartments, as well as what they construct with the materials thence derived. They appear, in short, to be no less skilful in mining than in building. Such is the general outline of the operations of this singular species ; but we are still more interested with the history which M. P. Huber has given of the labours of an individual ant. " One rainy day," he says, " I observed a labourer of the dark ash-coloured species (^Formica fusca) digging the ground near the aperture which gave entrance to the ant-hill. It placed in a heap the several fragments it had scraped up, and formed them' into small pellets, which it deposited here and there upon the nest. It returned constantly to the same place, and appeared to have a particular design, for it laboured with ardour and perseverance. I remarked a slight furrow, excavated in the ground in a straight line, representing the plan of a path or gallery. The labourer (the whole of whose move- ments fell under my immediate observation) gave it greater depth and breadth, and cleared out its borders ; and I saw, at length — in which I could not be deceived— that it had the intention of establishing an avenue which was to lead from one of the stories to the underground chambers. This path, which was about two or three inches in length, and 234 INSECT ARCHITECTURE. formed by a single ant, was opened above, and bordei'ed on each side by a buttress of earth. Its concavity, in the form of a pipe (gouttiere), was of the most perfect regularity : for the architect had not left an atom too much. The work of this ant was so well followed and understood, that I could almost to a certainty guess its next proceeding, and the very fragment it was about to remove. At the side of the opening where this path terminated was a second opening, to which it was necessary to arrive by some road. The same ant began and finished this under- taking without assistance. It furrowed out and opened another path, parallel to the first, leaving between each a little wall of three or four lines in height." Like the hive-bees, ants do not seem to work in concert, but each individual separately. There is, consequently, ar; occasional want of coincidence in the walls and arches ; but this does not much embarrass them, for a worker, on discovering an error of this kind, seems to know how to rectify it, as appears from the following observations : — "A wall," sa3^s M. Huber, "had been erected, with the view of sustaining a vaulted ceiling, still incomplete, that had been projected towards the wall of the opposite chamber. The workman who began constructing it, had given it too little elevation to meet the opposite parti- tion, upon which it was to rest. Had it been continued on the original plan, it must infallibly have met the wall at about one-half of its height ; and this it was necessary to avoid. This state of things very forcibly claimed my attention ; when one of the ants arriving at the place, and visiting the works, appeared to be struck by the difficulty which presented itself; but this it as soon obviated, by taking down the ceiling, and raising the wall upon which it reposed. It then, in my presence, constructed a new ceiling with the fragments of the former one. " When the ants commence any undertaking, one Avould suppose that they worked after some preconceived idea, which, indeed, would seem verified by the execution. Thus, should any ant discover upon the nest two stalks of plants which lie cross ways, a disposition favourable to the MASON-ANTS. 235 construction of a lodge, or some little beams that may be useful in forming its angles and sides, it examines the several parts with attention : then distributes, with much ' sagacity and address, parcels of earth in the spaces, and along the stems, taking from every quarter materials adapted to its object, sometimes not caring to destroy the work that others had commenced ; so much are its motions regulated by the idea it has conceived, and upon which it acts, with little attention to all else around it. It goes and returns, until the plan is sufficiently iinderstood by its companions. " In another part of the same ant-hill," continues M. Huber, " several fragments of straw seemed expressly jjlaced to form the roof of a large house ; a workman took advantage of this disposition. These fragments lying hori- zontally, at half-an-inch distance from the ground, formed, in crossing each other, an oblong parallelogram. The industrious insect commenced by placing earth in the several angles of this framework, and all along the little beams of whicli it was composed. The same workman afterwards placed several lows of the same materials against each other, when the roof became very distinct. On perceiving the possibility of profiting by another plant to support a vertical wall, it began laying the foundations of it ; other ants having by this time arrived, finished in common what this had commenced." * * Huber on Ants, p. 48. 236 INSECT ARCHITECTURE. M. Hiiber made most of his observations upon the pro- cesses followed by ants in glazed artificial hives or formi- ' caries. The preceding figure represents a view of one of his formicaries of mason-ants. We have ourselves followed np his observations, both on natural ant-hills and in artificial formicaries. On dig- ging cautiously into a natural ant-hill, established upon the edge of a garden-walk, Ave were enabled to obtain a pretty complete view of the interior structure. There were two stories, composed of large chambers, irregularly oval, communicating with each other b}^ arched galleries, the walls of all which were as smooth and well-polished as if they had been passed over by a plasterer's trowel. The floors of the chambers, we remarked, were by no means either horizontal or level, but all more or less sloped, and exhibiting in each chamber at least two slight depressions of an irregular shape. We left the under story of this nest untouched, with the notion that the ants might repair the upper galleries, of which we had made a vertical section ; but instead of doing so they migrated during the day to a large crack formed by the dryness of the weather, about a yard from their old nest. (J.E.) We put a number of yellow ants (^Formica flam), with their eggs and cocoons, into a small glass frame, more than half full of moist sand taken from their native hill, and placed in a sloping position, in order to see whether they would bring the nearly vertical, and therefore insecure, portion to a level by masonry. We were delighted to perceive that they immediately resolved upon performing the task which had been assigned them, though they did MASOX-ANTS. 237 not proceed very methodically in their manner of building ; for instead of beginning at the bottom and building upwards, many of them went on to add to the top of the outer surface, which increased rather than diminished the security of the whole. Withal, however, they seemed to know how far to go, for no portion of the newly-built wall fell ; and in two days they had not only reared a pyramidal mound to prop the rest, but had constructed several gal- leries and chambers for lodging the cocoons, which we had scattered at random amongst the sand. The new portion of this building is represented in the figure as supporting the upper and insecure parts of the nest. We are sorry to record that our ingenious little masons were found upon the third day strewed about the outside of the building dead or dying, either from over fatigue or perhaps from surfeit, as we had supplied them with as much honey as they could devour. A small colony o turf-ants have at this moment (July 28th, 1829) taken possession of the premises of their own accord. (J. R.) ( 238 ) CHAPTEE XV. STRUCTURES OF THE WOOD-ANT OR PISMIRE, AND OF CAR- PENTER-ANTS. The largest of onr British ants is that called the Hill- ant by Gould, the Fallow-ant by the English translator of Huber, and popularly the Pismire ; but which we think may be more appropriately named the Wood-ant (^Formica rufa, Latr.), from its invariable habit of living in or near woods and forests. This insect may be readily distinguished from other ants by the dusky black colour of its head and hinder parts, and the rusty brown of its middle. The structures reared by this species ai'e often of considerable magnitude, and bear no small resemblance to a rook's nest thrown ujDon the ground bottom upwards. They occur in abundance in the woods near London, and in many other parts of the country : in Oak of Honour wood alone, we are acquainted with the localities of at least two dozen, — some in the interior, and others on the hedge- banks on the outskirts of the wood. (J. E.) Tlie exterior of the nest is composed of almost every transportable material which the colonists can find in their vicinity : but the greater portion consists of the stems of withered grass and short twigs of trees, piled up in apparent confusion, but with sufficient regularity to render the whole smooth, conical, and sloping towards the base, for the purpose, we may infer, of carrying off rain- water. AVhen within reach of a corn-field, they often also pick up grains of wheat, barley, or oats, and carry them to the nest as building materials, and not for food, as was believed by the ancients. There are wonders enough ob- servable in the economy of ants, without having recourse to fancy — w^onders which made Aristotle extol the sagacity of bloodless animals, and Cicero ascribe to them not only WOOD-ANTS. 239 sensation, but mind, reason, and memory.* ^lian, how- ever, describes, as if be bad actual!}^ witnessed it, tbe ants ascending a stalk of growing corn, and throwing down "the ears which they bit off" to their companions below." Aldrovand assures us that he had seen their granaries ; and others pretend that they shrewdly bite off the ends of the grain to prevent it from germinating, j These are fables which accurate observation has satisfactorily contra- dicted. But these errors, as it • frequently happens, have con- tributed to a more perfect knowledge of the insects than we might otherwise have obtained ; for it was the wish to prove or disprove the circumstance of their storing up and feeding upon grain, which led Grould to make his observations on English ants ; as the notion of insects being produced from putrid carcases had before led Eedi to his ingenious experiments on their generation. Yet, although it is more than eighty years since Gould's book was published, we find the error still repeated in very respectable publications.;]: The coping which we above described as forming the exterior of the wood-ant's nest, is only a small portion of the structure, which consists of a great number of interior chambers and galleries, with funnel-shaped avenues lead- ing to them. The coping, indeed, is one of the most essential parts, and we cannot follow a more delightful guide than the younger Huber in detailing its formation. "The labourers," he says, "of which the colony is composed, not only work continually on the outside of their nest, but, differing very essentially from other species, who willingly remain in the interior, sheltered from the sun, they prefer living in the open air, and do not hesitate to carry on, even in our presence, the greater part of their operations. " To have an idea how the straw or stubble-roof is formed, let us take a view of the ant-hill at its origin, * In formica non modo sensus, seel etiam mens, ratio, memoria. t Aldrovandus de Formicis, and Johnston, Thaumatiirg. Nat. p. 35G. X See Professor Paxton's Illustrations of Scripture, i. 307. 240 INSECT ARCHITECTURE. wlien it is simply a cavity in the earth. Some of its future inhabitants are seen wandering about in search of materials fit for the exteiior work, with which, though rather irregularly, they cover up the enti-ance ; whilst others are employed in mixing the earth, thrown up in hollowing the interior, with fragments of Avood and leaves, which are every moment brought in by their fellow- assistants ; and this gives a certain consistence to the edifice, which increases in size daily. Our little architects leave here and there cavities, where they intend con- structing the galleries which are to lead to the exterior, and as they remove in the morning the barriers placed at the entrance of their nest the preceding evening, the passages are kept open during the whole time of its construction. We soon obsf^rved the roof to become convex ; but we should be greatly deceived did we con- sider it solid. This roof is destined to include many apart- ments or stories. Having observed the motions of these little builders through a pane of glass, adjusted against one of their habitations, I am thence enabled to speak with some degree of certainty upon the manner in which they are constructed. I ascertained that it is by excavating or mining the under portion of their edifice, that they form their spacious halls — low, indeed, and of heavy construc- tion, yet sufiiciently convenient for the use to which they are appropriated, that of receiving, at certain hours of the day, the larvae and pupee. " These halls have a free communication by galleries, made in the same manner. If the materials of which the ant-hill is composed were only interlaced, they would fall into a confused heap every time the ants attempted to bring them into regular order. This, however, is obviated by their tempering the earth with rain-water, which, after- wards hardened in the sun, so completel}' and efiectually binds together the several substances, as to permit the removal of certain fragments from the ant-hill without any injury to the rest ; it, moreover, strongly opposes the introduction of the rain. I never found, even after long and violent rains, the interior of the nest wetted to more WOOD-ANTS. 241 than a quarter of an inch from the suiface, provided it had not been previously out of repair, or deserted by its inhabitants. " The ants are extremely well sheltered in their chambers, the largest of which is placed nearly in the centre of the building ; it is much loftier than the rest, and traversed only by the beams that support the ceiling ; it is in this spot that all the galleries terminate, and this forms, for the most part, their usual residence. "As to the underground joortion, it can only be seen when the ant-hill is placed against a declivity ; all the interior may be then readily brought in view, by simply raising up the straw roof. The subten-anean residence consists of a range of apartments, excavated in the earth, taking an horizontal direction." * M. P. Huber, in order to observe the operations of the wood-ant with more attention, transferred colonies of them to his artificial formicaries, plunging the feet of the stand into water to prevent their escape till they were reconciled to their abode, and had made some progress in repairing it. On the next page is a figure of the apparatus which he used for this purpose. There is this remarkable difference in the nest of the wood-ants, that they do not construct a long covert way as if for concealment, as the yellow and the brown ants do. The wood-ants are not, like them, afraid of being surprised by enemies, at least during the day, when the whole colony is either foraging in the vicinity or employed on the exterior. But the proceedings of the wood-ants at night are well worthy of notice ; and when M. Huber began to study their economy, he directed his entire attention to their night proceedings. "I remarked," says he, "that their habitations changed in appearance hourly, and that the diameter of those spacious avenues, where so many ants could freely pass each other during the day, was, as night approached, gradually lessened. The aperture, at length, totally disappeared, the dome was closed on all sides, and the ants retired to the bottom of their nest. * Huber on Ants, p. 15. 242 IXSECT ARCHITECTURE. " In further noticing the apertures of these ant-hills, I fully ascertained the nature of the labour of its inhabitants, of which I could not before even guess the pui-port; for the surface of the nest presented such a constant scene of agitation, and so many insects were occupied in carrying materials in every direction, that the movement offered no other image than that of confusion. " I saw then clearly that they were engaged in stopping up passages ; and for this purpose they at first brought forward little pieces of wood, which they deposited near the entrance of those avenues they wished to close ; they placed them in the stubble ; they then went to seek other twigs and fragments of wood, which they disposed above the first, but in a different direction, and appeared to choose pieces of less size in proportion as the work advanced. They, at length, brought in a number of dried leaves, and other materials of an enlarged form, with which they covered the roof : an exact miniature of the art of our builders, when they form the covering of any building. Nature, indeed, seems everywhere to have anticipated the inventions of which we boast, and this is doubtless one of the most simple. CARPENTER-ANTS. 243 " Our little insects, now in safety in their nest, retire gradually to the interior before the last passages are closed ; one or two only remain without, or concealed behind the doors on guard, while the rest either take their repose, or engage in diiferent occupations in the most perfect security. I was impatient to know what took place in the morning upon these ant-hills, and therefore visited them at an early hour. I found them in the same state in which I had left them the preceding evening. A few ants were wandering about on the surface of the nest, some others issued from time to time from under the margin of their little roofs formed at the entrance of the galleries : others afterwards came forth, who began removing the wooden bars that blockaded the entrance, in which they readily succeeded. This labour occupied them several hours. The passages were at length free, and the materials with which they had been closed scat- tered here and there over the ant-hill. Every day, moining and evening, during the fine weather, I was a witness to similar proceedings. On days of rain the doors of all the ant-hills remained closed. When the sky was cloud}^ in the morning, or rain was indicated, the ants, who seemed to be aware of it, opened but in part their several avenues, and immediately closed them when the rain com- menced." * The galleries and chambers which are roofed in as thus described, are very similar to those of the mason-ants, being partly excavated in the earth, and partly built with the clay thence procured. It is in these they pass the night, and also the colder months of the winter, when they become torpid, or nearly so, and of course require not the winter granaries of corn with which the ancients fabulously furnished them. Carpenter-Ants. The ants that work in wood perform much more exten- sive operations than any of the other carpenter insects which we have mentioned. Their only tools, like those * Huber on Ants, p. 11. 244 INSECT ARCHITECTURE. of bees and wasps, are their jaws or mandibles ; but though, these may not appear so curiously constructed as the ovipositor file of the tree-hopper (^Cicada), or the rasp and saw of the saw-flies {Tenthredinidoe), they are no less efficient in the performance of what is required. Among the carpenter-ants the emmet or jet-ant (F.fuliguwsa) holds the first rank, and is easily known by being rather less in size than the wood-ant, and by its fine shining black colour. It is less common in Britain than some of the preceding, though its colonies may occasionally be met with in the trunks of decaying oak or willow trees in hedges. " The labourers," says Huber, " of this species work always in the interior of trees, and are desirous of being screened from observation : thus every hope on our part is precluded of following them in their several occupations. I tried every expedient I could devise to surmount this difficulty ; I endeavoured to accustom these ants to live and work under my inspection, but all my eff"orts were unsuccessful ; they even abandoned the most considerable portion of their nest to seek some new asylum, and spurned the honey and sugar which I offered them for nourishment. I was now, by necessity, limited to the inspection only of their edifices ; but, by decomposing some of the fragments with care, I hoped to acquire seme knowledge of their organization. " On one side I found horizontal galleries, hidden in great part by their walls, which follow the circular direc- tion of the layers of the wood; and on another, parallel galleries, separated by extremely thin partitions, having no communication except by a few oval apertures. Such is the nature of these works, remarkable for their delicacy and lightness. " In other fragments I found avenues which opened laterally, including portions of walls and transverse par- titions, erected here and there within the galleries, so as to form separate chambers. When the work is further advanced, round holes are alwaj^s observed, encased, as it were, between two pillars cut out in the same wall. CARPENTER-ANTS. 245 These holes in course of time become square, and the pillars, originally arched at both ends, are worked into regular columns by the chisel of our sculptors. This, then, is the second specimen of their art. This portion of the edifice will probably remain in this state. " But in another quarter are fragments differently wrought, in which these same partitions, pierced now in every part, and hewn skilfully, are transformed into co- lonnades, which sustain the upper stories, and leave a free communication throughout the whole extent. It can readily be perceived how parallel galleries, hollowed out upon the same plan, and the sides taken down, leaving only from space to space what is necessary to sustain their ceilings, may form an entire stor}^ ; but as each has been pierced separately, the flooring cannot be very level : this, however, the ants turn to their advantage, since these furrows are better adapted to retain the larvas that may be placed there. "The stories constructed in the great roots offer greater irregularity than those in the very body of the tree, arising either from the hardness and interlacing of the fibres, which renders the labour more difficult, and obliges the labourers to depart from their accustomed manner, or from their not observing in the extremities Portion of a Tree, with Cliambers and Galleries chiseled out by Jet-Ants. of their edifice the same arrangement as in the centre ; whatever it be, horizontal stories and numerous partitions 246 IXSECT ARCHITECTURE. are still found. If the work be less regular, it becomes more delicate : for the ants, profiting by the hardness and solidity of the materials, give to their building an extreme degree of lightness. I have seen fragments of from eight to ten inches in length, and of equal height, formed of wood as thin as paper, containing a number of apartments, and presenting a most singular appearance. At the entrance of these apai-tments, worked out with so much care, are very considerable openings ; but in place of chambers and extensive galleries, the layers of the wood are hewn in arcades, allowing the ants a free passage in every direction. These may be regarded as the gates or vestibules conducting to the several lodges."* It is a singular circumstance in the structures of these ants, that all the wood which they carve is tinged of a black colour, as if it were smoked ; and M. Huber Avas not a little solicitous to discover whence this arose. It certainly does not add to the beauty of their streets, which look as sombre as the most smoke-dyed walls in the older lanes of the metropolis. M. Huber could not satisfy himself whether it was caused by the exposure of the wood to the atmosphere, by some emanation from the ants, or by the thin layers of wood being acted upon or decomposed by the formic acid.f But if any or all of these causes operated in blackening the wood, we should be ready to anticipate a similar effect in the case of other species of ants which inhabit trees ; yet the black tint is only found in the excavations of the jet-ant. We are acquainted with several colonies of the jet- ants, — one of which, in the roots and trunk of an oak on the road from Lewisham to Sydenham, near Brockley, in Kent, is so extremely populous, that the numbers of its inhabitants appeared to us beyond any reasonable estimate. None of the other colonies of this species which we have seen appear to contain many hundreds. On cutting into the root of the before-mentioned tree, we found the vertical excavations of much larger dimen- * Huber, p. 56. f The acid of ants. CARPENTER-ANTS. 247 sions, both in width and depth, than those represented by Hiiber in the preceding cut (page 245). What sur- prised us the most was to see the tree growing vigor- ously and fresh, though its roots were chiseled in all directions by legions of workers, while every leaf, and ever}^ inch of the bark, was also crowded by parties of foragers. On one of the low branches we found a de- serted nest of the white-throat {Sylvia cinerea, Temminck), in the cavity of which they were piled upon one another as close as the unhappy negroes in the hold of a slave- ship ; but we could not discover what had attracted them hither. Another dense group, collected on one of the branches, led us to the discovery of a very singular oak gall, formed on the bark in the shape of a pointed cone, and crowded together. It is probable that the juice which they extracted from these galls was much to their taste. (J.E.) Beside the jet-ant, several other species exercise the art of carpentry, — nay, what is more wonderful still, they have the ingenuity to knead up, with spiders'- web for a cement, the chips which they chisel out into a material with which they construct entire chambers. The species which exercise this singular art are the Ethiopian (Formica nigra) and the yellow ant (F. flava)* We once observed the dusky ants (F.ficsca), at Black- heath, in Kent, busil}^ employed in carrying out chips from the interior of a decaying black poplar, at the root of which a colony was established ; but, though it thence appears that this species can chisel wood if they choose, yet they usually burrow in the earth, and by preference, as we have remarked, at the root of a tree, the leaves of which supply them with food. Among the foreign ants we may mention a small yellow ant of South America, described by Dampier, which seems, from his account, to construct a nest of green leaves, "Their sting," he says, "is like a spark of fire ; and they are so thick among the boughs in some * Huber. 248 INSECT ARCHITECTURE. places, that one shall be covered with them before he is aware. These creatures have nests on great trees, placed on the body between the limbs : some of their nests are as big as a hogshead. This is their winter habitation ; for in the wet season they all repair to these their cities, where they preserve their eggs. In the dry season, when they leave their nests, they swarm all over the woodlands, for they never trouble the savannahs. G-reat paths, three or four inches broad, made by them, may be seen in the woods. They go out light, but bring home heavy loads on their backs, all of the same sub- stance, and equal in size. I never observed anything besides pieces of green leaves, so big that I could scarcely see the insect for his burthen ; yet they would march stoutly, and so many were pressing forward that it was a very pretty sight, for the path looked perfectly green with them." Ants observed in Xew South Wales, by the gentlemen in the expedition under Captain Cook, are still more in- teresting. *' Some,'' we are told, " are as green as a leaf, and live upon trees, where they build their nests of various sizes, between that of a man's head and his fist. These nests are of a very furious structure : they are formed by bending down several of the leaves, each of which is as broad as a man's hand, and gluing the points of them together, so as to form a purse. The viscous matter used for this purpose is an animal juice which nature has enabled them to elaborate. Their method of first bending down the leaves we had no opportunity to observe ; but we saw thousands uniting all their strength to hold them in this position, while other busy multitudes were employed within in applying this gluten that was to prevent their returning back. To satisfy ourselves that the leaves were bent and held down by the eiforts of these diminutive artificers, we disturbed them in their work ; and as soon as they were driven from their stations, the leaves on which they were em- ployed sprang up with a force much greater than we could have thought them able to conquer by any com- CARPENTER-ANTS. 249 bination of their strength. But, though we gratified our curiosity at their expense, the injury did not go un- revenged; for thousands immediately threw themselves upon us, and gave us intolerable pain with their stings, especially those which took possession of our necks and hair, from whence they were not easily driven. Their sting was scarcely less painful than that of a bee ; but, except it was repeated, the pain did not last more than a minute. "Another sort are quite black, and their operation and manner of life are not less extraordinary. Their habitations are the inside of the branches of a tree, which they contrive to excavate by working out the pith almost to the extremity of the slenderest twig, the tree at the same time flourishing as if it had no such inmate. When we first found the tree we gathered some of the branches ; and were scarcely less astonished than we should have been to find that we had profaned a consecrated grove, where every tree, upon being wounded, gave signs of life ; for we were instantly covered with legions of these animals, swarming from every broken bough, and inflicting their stings with incessant violence. " A third kind we found nested in the root of a plant, which grows on the bark of trees in the manner of mistletoe, and which they had perforated for that use. This root is commonly as big as a large turnijD, and sometimes much bigger. When we cut it we found it intersected by innumerable winding passages, all filled with these animals, by which, however, the vegetation of the plant did not appear to have suffered any injury. We never cut one of these roots that was not inhabited, though some were not bigger than a hazel-nut. The animals themselves are very small, not more than half as big as the common red ant in England. They had stings, but scarcely force enough to make them felt : they had, however, a power of tormenting us in an equal, if not in a greater degree ; for the moment we handled the root, they swarmed from innumerable holes, and running about those parts of the body that were uncovered, produced a 250 INSECT ARCHITECTURE. titillation more intolerable than pain, except it is increased to great violence."* The species called sngar-ants in the West Indies are particularly destructive to the sugar-cane, as well as to lime, lemon, and orange-trees, by excavating their nests at the roots, and so loosening the earth that they are fre- quently uprooted and blown down by the winds. If this does not happen, the roots are deprived of due nourish- ment, and the plants become sickly and die.f * Hawkesworth's Account of Cook's First Voyage, t Phil. Trans., xxx., p. 346. ( 251 ) CHAPTEK XYI. STRUCTURES OF WHITE ANTS, OR TERMITES. When we look back upon the details wliicli we have given of the industry and ingenuity, of numerous tribes of insects, both solitary and social, Ave are induced to think it almost impossible that they could be surpassed. The structures of wasps and bees, and still more those of the wood-ant (^Formica rufct), when placed in comparison with the size of the insects, equal our largest cities com- pared with the stature of man. But when we look at the buildings erected by the wdiite ants of tropical climates, all that w^e have been surveying dwindles into insignificance. Their industry appears greatly to surpass that of our ants and bees, and they are certainly more skilful in architectural contrivances. The elevation, also, of their edifices is more than five hundred times the height of the builders. Were our houses built according to the same proportions, they w^onld be twelve or fifteen times higher than the London Monument, and four or five times higher than the pyramids of Egypt, with corresponding dimensions in the basements of the edifices. These state- ments are, perhaps, necessary to impress the extraordinary labours of ants upon the mind ; for we are all more or less sensible to the force of comparisons. The analogies between the works of insects and of men are not perfect ; for insects are all provided with instruments peculiarly adapted to the end w^hich they instinctively seek, while man has to form a plan by progressive thought, and upon the experience of others, and to complete it with tools which he also invents. The termites do not stand above a quarter of an inch high, while their nests are frequently twelve feet ; and Jobson mentions some which he had seen as hio-h as 252 INSECT ARCHITECTURE. twenty feet; "of compass," he adds, "to contain a dozen men, with the heat of the sun baked into that hardness, that we used to hide ourselves in the ragged tops of them when we took up stands to shoot at deer or wild beasts."* Bishop Heber saw a number of these high ant-hills in India, near the principal entrance of the Sooty or Moor- shedabad river. "Many of them," he says, "were five or six feet feet high, and probably seven or eight feet in cir- cumference at the base, partially overgrown with grass and ivy, and looking at a distance like the stumps of decayed trees. I think it is Ctesias, among the Greek writers, who gives an account alluded to by Lucian in his * Cock,' of monstrous ants in India, as large as foxes. The falsehood probably originated in the stupendous fabrics which they rear here, and which certainly might be supposed to be the work of a much larger animal than their real architect."t Herodotus has a similar fable of the enormous size and brilliant appearance of the ants of India. Nor is it only in constructing dwellings for themselves that the termites of Africa and of other hot climates employ their masonic skill. Though, like our ants and wasps, they are almost omnivorous, jet wood, particularly when felled and dr)^, seems their favourite article of food ; but they have an utter aversion to feeding in the light, and always eat their way with all expedition to the interior. It thence would seem necessary for them either to leave the bark of a tree, or the outer portion of the beam or door of a house, undevoured, or to eat in open day. They do neither ; but are at the trouble of constructing galleries of clay, in which they can conceal themselves, and feed in security. In all their foraging excursions, indeed, they build covert ways, by which they can go out and return to their encampment. J Others of the species (for there are several), instead of building galleries, exercise the art of miners, and make * Jobson's Gambia, in Pm'clias's Pilgrim, ii. p. 1570. t Heber's Jom-nal, vol. i. p, 248. X Smeatliman, in Phil. Trans., vol. Ixxi. WHITE ANTS. 253 their approaches under ground, penetrating beneath the foundation of houses or areas, and rising again either through the floors, or by entering the bottom of the posts that support the building, when they follow the course of the fibres, and make their way to the top, boring holes and cavities in diiferent places, as they proceed. Multitudes enter the roof, and intersect it with pipes or galleries, formed of wet clay ; which serve for passages in all direc- tions, and enable them more readily to fix their habitations in it. They prefer the softer woods, such as pine and fir, which they hollow out with such nicety, that they leave the surface whole, after having eaten away the inside. A shelf or plank attacked in this manner, looks solid to the eye, when, if weighed, it will not out-balance two sheets of pasteboard of the same dimensions. It sometimes happens that they carry this operation so far on stakes in the open air, as to render the bark too flexible for their purpose ; when they remedy the defect by plastering the whole stick with a sort of mortar which they make with clay ; so that, on being struck, the form vanishes, and the artificial covering falls in fragments on the ground. In the woods, when a large tree falls from age or accident, they enter it on the side next the ground, and devour it at leisure, till little more than the bark is left. But in this case they take no precaution of strengthening the outward defence, but leave it in such a state as to deceive an eye unaccustomed to see trees thus gutted of their insides : and " you may as well," says Mr. Smeathman, " step upon a cloud." It is an extraordinary fact, that when these crea- tures have formed pipes in the roof of a house, instinct directs them to prevent its fall, which would ensue from their having sapped the posts on which it rests ; but as they gnaw away the wood, thej fill up the interstices with clay, tempered to a surprising degree of hardness ; so that, when the house is pulled down, these posts are transformed from wood to stone. They make the walls of their gal- leries of the same composition as their nests, varying the materials according to their kind : one species using the red clay, another black clay, and the third a woody substance, 254 IXSECT ARCHITECTURE. cemented with gums, as a security from the attacks of their enemies, particularly the common ant, which, being defended by a strong, horny shell, is more than a match for them ; and when it can get at them, rapaciously seizes them, and drags them to its nest for food for its young brood. If an}^ accident breaks down part of their walls, they repair the breach with all speed. • Instinct guides them to perform their office in the creation, by mostly con- fining their attacks to trees that are beginning to decay, or such timber as has been severed from its roots for use, and would decay in time, Vigorous, healthy trees do not re- quire to be destroyed, and, accordingly, these consumers have no taste for them.* M. Adanson describes the termites of Senegal as con- structing covert ways along the surface of wood which they intend to attack ; but though we have no reason to distrust so excellent a naturalist, in describing what he saw, it is certain that they more commonly eat their way into the interior of the wood, and afterwards furm the galleries, when they find that they have destroyed the wood till it will no longer afford them protection. But it is time that we should come to their principal building, which may, with some propriety, be called a city ; and, according to the method we have followed in other instances, we shall trace their labours from the com- mencement. We shall begin with the operations of the species which may be appropriately termed the AVarrior {Termesfatalis, Linn. ; 2\ bellicosus, Smeath.) We must premise, that though they have been termed white ants, they do not belong to the same order of insects with our ants ; yet they have a'slight resemblance to ants in their form, but more in their economy. Smeathman, to whom we owe our chief knowledge of the genus, describes them as consisting of kings, queens, soldiers, and workers, and is of opinion that the workers are larvae, the soldiers nymph^e, and the kings and queens the perfect insects. In this opiuion he coincides with Sparrmannf and others; but Latreille is inclined to think, from what he observed * Smeatlinian. f Quoted by De Geer, vol. vii. WHITE ANTS. 255 in a European species ( Termes liicifugiis), found near Bor- deaux, that the soldiers form a distinct race, like the neuter workers among bees and ants, while the working Termes bellicosus in the winged state. termites are larvae,* which are furnished with strong man- dibles for gnawing ; when they become nymphs, the rudi- ments of four wings appear, which are fully developed in the perfect insects. In this state, they migrate to form new colonies, but the greater number of them perish in a few hours, or become the prey of birds, and even the natives, who fry them as delicacies. " I have discoursed with several genllemen," says Smeathman, "upon the taste of the white ants, and on comparing notes, we have always agreed that they are most delicious and delicate eating. One gentleman compared them to sugared mar- row, another to sugared cream and a paste of sweet almonds. "t Mr. Smeathman's very interesting paper affords us the most authentic materials for the further description of these wonderful insects ; and we therefore continue partly to extract from, and partly to abridge, his account. The few pairs that are so fortunate as to survive the various casualties that assail them, are usually found by workers (larvae), which, at this season, are running con- tinually on the surface of the ground, ■ on the watch for them. As soon as they discover the objects of their search, they begin to protect them from their surrounding enemies, by inclosing them in a small chamber of clay, where they become the parents of a new community, and are distin- * Hist. Nat. Genorale, vol. xiii. p. 60. t Smeathman, in Pliil. Trans, vol. Ixxi. p. 169, note. 256 INSECT ARCHITECTURE. guislied from the other inhabitants of the nest, by the title of king and queen. Instinct directs the attention of these labouring insects to the preservation of their race, in the protection of this pair and their offspring. The chamber that forms the rudiment of a new nest is contrived for their safety, but the entrances to it are too small to admit of their ever leaving it ; consequently, the charge of the eggs devolves upon the labourers, who construct nurseries for their reception. These are small, irregularly-shaped chambers, placed at first round the apartment of the king and queen, and not exceeding the size of a hazel-nut ; but in nests of long standing they are of great comparative magnitude, and distributed at a greater distance. The re- ceptacles for hatching the young are all composed of wooden materials, apparently joined together with gum, and, by way of defence, cased with clay. The chamber that contains the king and queen is nearly on a level with the surface of the ground ; and as the other apart- ments are formed about it, it is generally situated at an equal distance from the sides of the nest, and directly beneath its conical point. Those apartments which consist of nurseries and magazines of provisions, form an intricate labyrinth, being separated by small, empty chambers and galleries, which surround them, or afford a communication from one to another. This labyrinth extends on all sides to the outward shells, and reaches up within it to two- thirds or more of its height, leaving an open area above, in the middle, under the dome, which reminds the spec- tator of the nave of an old cathedral. Around this are raised three or four large arches, which are sometimes two or three feet high, next the front of the area, but diminish as they recede further back, and are lost amidst the innumerable chambers and nurseries behind them. Eveiy one of these buildings consists of two distinct parts, the exterior and the interior. The exterior is one large shell, in the manner of a dome, large and strong enough to inclose and shelter the interior from the vicis- situdes of the weather, and the inhabitants from the attacks of natural or accidental enemies. It is always, therefore. WHITE ANTS. 257 miicli stronger tlian the interior building, wliicli is the habitable part, divided, with a wonderful kind of regularity and contrivance, into an amazing number of apartments for the residence of the king and queen, and the nursing of the numerous progeny ; or for magazines, which are always found well filled with stores and provisions. The hills make their first appearance above ground by a little turret or two, in the shape of sugar-loaves, which are run a foot high or more. Soon after, at some little distance, while the former are increasing in height and size,°they raise others, and so go on increasing their number, and widen- ing them at the base, till their works below are covered with these turrets, of which they always raise the highest and largest in the middle, and, by filling up the intervals between each turret, collect them into one dome. They are not very curious or exact in the workmanship, except in making them very solid and strong ; and when, by their joining them, the dome is completed, for which purpose the turrets answer as scaffolds, they take away the middle ones entirely, except the tops, which, joined together, make the crown of the cupola, and apply the clay to the building of the works within, or to erecting fresh turrets for the purpose of raising the hillock still higher ; so that some part of the clay is probably used several times, like the boards and posts of a mason's scaffolds. When these hills are little more than half their height, it is a common practice of the wild bulls to stand as sentinels on them, while the rest of the herd are ruminat- ing below. They are sufficiently strong for that purpose ; and at their full height, answer excellently well as places of look-out ; and Mr. Smeathman has been, with four more, on the top of one of these hillocks, to watch for a vessel in sight. The outward shell, or dome, is not only of use to protect and support the interior buildings from external violence and the heavy rains, but to collect and preserve a regular degree of the waimth and moisture necessary for hatching the eggs and cherishing the young. The royal chamber occupied by the king and queen appears to be, in the opinion of this little people, of the most consequence, 258 INSECT ARCHITECTURE. being always situated as near the centre of the interior building as possible. It is always nearly in the shape of half an egg, or an obtuse oval, within, and may be supposed to represent a long oven. In the infant state of the colony, it is but about an inch in length; but in time will be increased to six or eight inches, or more, in the clear, being always in proportion to the size of the queen, who, increasing in bulk as in age, at length requires a chamber of such dimensions. Queen distended with Eggs. Its floor is perfectly horizontal, and, in large hillocks, sometimes more than an inch thick of solid clay. The roof, also, which is one solid and well-turned oval arch, is tj-enerally of about the same solidity, but in some places it is not a quarter of an inch thick, on the sides where it joins the floor, and where the doors or entrances are made level with it, at nearly equal distances from each other. These entrances will not admit any animal larger than the soldiers or labourers ; so that the king and the queen (who is, at full size, a thousand times the weight of a king) can never possibly go out, but remain close prisoners. The royal chamber, if in a large hillock, is surrounded by a countless number of others, of different sizes, shapes, and dimensions; but all of them arched in one way or another — sometimes elliptical or oval. These either open into each other, or communicate by passages as wide as, and are evidently made for, the soldiers and attendants, of whom o-reat numbers are necessary, and always in waiting. These apartments are joined by the magazines and nurseries. WHITE ANTS. 259 The former are chambers of clay, and are always well filled with provisions, which, to the naked eye, seem to consist of the raspings of wood, and plants which the termites de- stroy ; but are found by the microscope to be principally the gums or inspissated juices of plants. These are thrown together in little masses, some of w^hich are finer than others, and resemble the sugar about preserved fruits; others are like tears of gum, one quite transi;)arent, another like amber, a third brown, and a fourth quite opaque, as we see often in parcels of ordinarj^ gums. These magazines are intermixed with the nurseries, which are buildings totally different from the rest of the apartments ; for these are composed entirely of wooden materials, seemingly joined together with gums. Mr. Smeathman calls them the nurseries, because they are invariably occupied by the eggs and young ones, which appear at first in the shape of labourers, but white as snow. These buildings are exceed- ingly compact, and divided into many very small irregular- shaped chambers, not one of which is to be found of half an inch in width. They are placed all round, and as near as possible to the royal apartments. When the nest is in the infant state, the nurseries are close to tlie royal chambers ; but as, in process of time, the queen enlarges, it is necessary to enlarge the chamber for her accommodation ; and as she then lays a greater number of eggs, and requires a greater number of at- tendants, so it is necessary to enlarge and increase the number of the adjacent apartments ; for which purpose the small nurseries which are first built are taken to pieces, rebuilt a little further of a size larger, and the number of them increased at the same time. Thus they continually enlarge their apartments, pull down, repair, or rebuild, according to their wants, with a degree of sagacity, regularity, and foresight, not even imitated by any other kind of animals or insects. All these chambers, and the passages leading to and from them, being arched, they help to support each other ; and while the interior large arches prevent them from falling into the centre, and keep the area open, the ex- 260 INSECT ARCHITECTURE. terior building supports them on the outside. There are, comparatively speaking, few openings into the great area, and they, for the most part, seem intended only to admit into the nurseries that genial warmth which the dome collects. The interior building, or assemblage of nurseries, chambers, &c., has a flattish top or roof, with- out any perforation, which would keep the apartments below dry, in case through accident the dome should receive any injury, and let in water; and it is never exactly flat and uniform, because the insects are always adding to it by building more chambers and nurseries ; so that the division or columns between the future arched apartment resemble the pinnacles on the fronts of some old buildings, and demand particular notice, as affording one proof that for the most part the insects project their arches, and do not mak^e them by excavation. The area has also a flattish floor, whicli lies over the royal cham- ber, but sometimes a good height above it, having nurse- ries and magazines between. It is likewise waterproof, and contrived to let the water off if it should get in, and run over by some short way into the subterraneous pas- sages, which run under the lowest apartments in the hill in various directions, and are of an astonishing size, being wider than the bore of a great cannon. One that Mr. Smeathman measured was perfectly cylindrical, and thirteen inches in diameter. These subterraneous j)assages, or galleries, are lined very thick with the same kind of clay of which the hill is composed, and ascend the inside of the outward shell in a spiral manner ; and wind- ing round the whole building up to the top, intersect each other at different heights, opening either immedi- ately in the dome in various places, and into the interior building, the new turrets, &c., or communicating with them by other galleries of different diameters, either cir- cular or oval. From every part of these large galleries are various sraair covert ways, or galleries leading to different parts of the building. Under ground there are a great many that lead downward by sloping descents, three and four WHITE ANTS. 261 feet perpendicular among the gravel, whenc^e the workers cull the finer parts, which, being kneaded up in their mouths to the consistence of mortar, become that solid clay or stone of which their hills and all their buildings, except their nurseries, are composed. Other galleries again ascend, and lead out horizontally on every side, and are carried under ground near to the surface a vast distance : for if all the nests are destroyed within a hundred yards of a house, the inhabitants of those which are left unmolested farther off, will still carry on their subterraneous galleries, and, invading it by sap and mine, do great mischief to the goods and merchandises contained in it. It seems there is a degree of necessity for the galleries under the hills being thus large, since they are the great thoroughfares for all the labourers and soldiers going forth or returning, whether fetching clay, wood, w^ater, or provisions ; and they are certainly well calculated for the purposes to wdiich they are applied by the spiral slo^^e which is given them ; for if they were perpendicular, the labourers would not be able to carry on their building with so much facility, as they ascend a perpendicular with great difficulty, and the soldiers can scarcely do it at all. It is on this account that sometimes a road like a ledge is made on the perpendicular side of any part of the building within their hill, which is flat on the upper surface and half an inch wide, and ascends gradually like a staircase, or like those winding roads which are cut on the sides of hills and mountains, that would otherwise be inaccessible ; by which and similar contrivances they travel with great facility to every interior part. This, too, is probably the cause of their building a kind of bridge of one great arch, which answers the pur- pose of a flight of stairs from the floor of the area, to some opening on the side of one of the columns that sup- port the great arches. This contrivance must shorten the distance exceedingly to those labourers who have the eggs to carry from the royal chamber to some of the upper nurseries, which in some hills would be four or five feet in the straightest line, and much more if carried 2G2 TxsECT architecturp:. tliroiigli all the winding passages leading tlirongli tlie inner chambers and apartments. Mr. Smeathman foimd one of these bridges, half an inch broad, a quarter of an inch thick, and ten inches long, making the side of an elliptic arch of proportionable size ; so that it is wonderful it did not fall over or break by its own weight before the}^ got it joined to the side of the colnnni above. £5 ri 2 It was strengthened by a small arch at the bottom, and had a hollow or groove all the length of the npper smface, WHITE ANTS. 263 either made purposely for the inhabitants to travel over with more safet}^ or else, which is not improbable, worn by frequent treading. Turret-building White Ants. Apparently more than one species smaller than the pre- ceding, such as the Termes mordax and T. atrox of Smeath- man, construct nests of a very different form, the figures of which resemble a pillar, with a large mushroom for a capital. These turrets are composed of well-tempered black earth, and stand nearly three feet high. The conical mushroom-shaped roof is composed of the same material, and the brims hang over the column, being three or four inches wider than its perpendicular sides. Most of them, Turret A'ests of White Auts. One nest is represented eut tlirough, witli the upijer part lying on tlie ground. says Smeathman, resemble in shape the body of a round windmill, but some of the roofs have little elevation in the middle. When one of these turrets is completed, the insects do not afterwards enlarge or alter ; but if it be found too small for them, they lay the foundation of another at a few inches' distance. They sometimes, but not often, begin the second before the first is finished, and a third before they have completed the second. Five or six of these 264 IXSECT ARCHITECTURE. singular turrets in a group may be seen in the thick woods at the foot of a tree. They are so very strongly built, that in case of violence, they will sooner tear up the gravel and solid heart of their foundation than break in the middle. When any of them happen to be thus thrown down, the insects do not abandon them ; but, using their over-turned column as a basis, they run up another per- pendicularly from it to the usual height, fastening the under part at the same time to the ground, to render it the more secure. The interior of a turret is pretty equally divided into innumerable cells, irregular in shape, but usually more or less angular, generally quadrangular or pentagonal, though the angles are not well defined. Each shell has at least two entrances ; but there are no galleries, arches, nor wooden nurseries, as in the nests of the warrior {T. hellico- sus). The two species which build turret nests are very ditferent in size, and the dimensions of the nests differ in proportion. The White Ants of Trees. Latreille's species of white ant ( Termes lucifugus, Eossi), formerly mentioned as found in the south of Europe, appear to have more the habits of the jet ant, described page 243, than their congeners of the tropics. They live in the interior of the trunks of tiees, the wood of which they eat, and form their habitations of the galleries which they thus excavate. M. Latreille says they appear to be fur- nished with an acid for the purpose of softening the wood, the odour of which is exceedingl}^ pungent. They prefer the j)art of the wood nearest to the bark, which they are careful not to injure, as it atfords them protec- tion. All the walls' of their galleries are moistened with small globules of a gelatinous substance, similar to gum Arabic. They are chiefly to be found in the trunks of oak and pine trees, and are very numerous.* * Lahvillc, Hist. Nat. Gent rale, torn. xiii. p. G4. WHITE ANTS. ' 265 Another of the species {Termes arhorum), described by Smeathman, builds a nest on the exterior of trees, alto- gether different from any of the preceding. These are of a spherical or oval shape, occupying the arm or branch of a tree sometimes from seventy to eighty feet from the ground, and as large, in a few instances, as a sugar-cask. The composition used for a building material is apparently similar to that used by the warriors for constructing their nurseries, being the gnawings of wood in very small par- ticles, kneaded into a paste with some species of cement or glue, procured, as Smeathman supposes, partly from gum- miferous trees, and partly from themselves ; but it is more probable, we think, that it is wholly secreted, like the wax of bees, by the insects themselves. With this cement, whatever may be its composition, they construct their cells, in which there is nothing very wonderful except their great numbers. They are very firmly built, and so strongly attached to the trees, that they will resist the most violent tornado. It is impossible, indeed, to detach them, except by cutting them in pieces, or sawing off the branch, which is frequently done to procure the insects for young turkeys. (See engraving, p. 262, for a figure of this nest.) This species very often, instead of selecting the bough of a tree, builds in the roof or wall of a house, and unless observed in time, and expelled, occasions considerable damage. It is easier, in fact, to shut one's door against a fox or a thief, than to exclude such insidious enemies, whose aversion to light renders it difficult to trace them even when they are numerous. If we reflect on the prodigious numbers of those insects, and their power and rapidity of destroying, we cannot but admire the wisdom of Providence in creating so inde- fatigable and useful an agent in countries where the decay of vegetable substances is rapid in proportion to the heat of the climate. We have already remarked that they always prefer decaying or dead timber ; and it is indeed a very general law among insects which feed on wood to prefer what is unsound; the same principle holds with respect to fungi, lichens, and other parasitical plants. 266 INSECT ARCHITECTURE. All the species of Termites are not social ; but the solitary ones do not, like their congeners, distinguish themselve