\
THE LIBRARY
OF
THE UNIVERSITY
OF CALIFORNIA
PRESENTED BY
PROF. CHARLES A. KOFOID AND
MRS. PRUDENCE W. KOFOID
THE LIBRARY OF ENTERTAINING KNOWLEDGE.
INSECT
TRANSFORMATIONS.
BOSTON :
LILLY & WAIT, (late WELLS # LILLY,)
.tfG.tf H. Carvill, and E. Bliss, New-York; Carey ^ Hart, Philadel-
phia ; W. 4- J. Neal, and E. J. Coale, Baltimore ; P. Thompson $ Ho-
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Alexandria; R. D. Sanxay, Richmond; C. P. M'Kennie, Charlottes-
ville ; W. H. Berrett, Charleston, S. C.; Salmon Hall, Newbern, N.C. ;
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ler & Son, Northampton ; Whipple $ Lawrence, Salem ; Eli French,
Dover; H. S, Favor, Eastport; and S. Colman, Portland.
1831.
CONTENTS. /
i v> ^ i -
SECTION I. EGGS OF INSECTS,
CHAPTER I. INTRODUCTORY.
Page
All insects come from eggs, 1
Curious experiment of Kircher, 2
Virgil's receipt for making a swarrn of bees,
Origin of these ancient errors, 4
Bees in Sampson's lion accounted for, 7
Fancies of Robinet and Darwin, 9
Theory of spontaneous generation, 10
Popular errors respecting blight, 11
Dr Good's account of blight, 12
No insect eggs afloat in the air, 14
Specific gravity of insect eggs, 15
Theoretical accounts of honey-dew, 16
Accounted for by experiments, 18
Instantaneous appearance of insects, 19
The f worm i' the, bud' traced to its egg, 20
Insectiferous winds, 22
Supposed shower of frogs, snails^ &c, 23
Diffusion of the seeds of plants, 24
Insects jet out their eggs from fear, 25
Origin of mosses on walls, 27
Origin of mould in the heart of an apple, 30
CHAPTER II.
Physiology of insects' eggs, 33
Theory of colours meant for concealment, ib.
Disproved in the case of the eggs of birds, 34
Illustrated from insect eggs, 35
Cause of the colours in eggs, 36
Structure of insects' eggs, 38
Eggs of ants, spiders, and glow-worms, 39
Form of insect eggs, 40
Cause of the oval form in birds' eggs, 41
Sculpture of the eggs of insects, ib.
Curious appendages to eggs, 43
Eggs with foot stalks, 46
Number of irisect eggs, and their fecundity, compared
with other animals, 46
CHAPTER III.
Maternal care of insects respecting their eggs, 49
Instanced in a carpenter bee (Chelostoma), 50
Ichneumons compared to the cuckoo, 52
Proceedings of a solitary bee (Halictus), 53
Stratagems of a solitary wasp (Cereem)j 54
M368511
iv CONTENTS.
Ovipositor of an ichneumon (Pimpla), 56
Experiments of Reaumur, 57
Common mistakes of Naturalists, 59
Parasite of the cabbage caterpillar (Pontia)>
Egg parasites,
Parasites of the aphides,
Singular parasite of the cock-roach,
Rare parasites of bees and wasps, 67
Tact of insects in discovering food for their young, 68
Sometimes select exotic plants, 69
Instanced in a leaf-miner (Tephritis?), 70
Solitary and gregarious caterpillars, 71
Life-boat of eggs constructed by the gnat, 72
Experiments upon it,
Infallibility of instinct questioned, 76
Mistakes of instinct, 77
CHAPTER IV.
Hybernation of insects' eggs, 79
Proceedings of the gypsey moth compared to the eider
duck, ib.
Singular groups of eggs, 81
Protection of eggs from heat, 83
Anal tweezers of moths, 84
Eggs in spiral groups, 85
Arched form of the lackey moth's eggs, 86
Hybernation of the eggs of aphides, 87
Singular protection of the eggs of cocci, 88
Coccus of the hawthorn, 90
Shell-formed coccus of the currant, 92
Hybernation of spiders' eggs, 93
Curious spider's nests, 94
Eggs of the vapourer moth on its cocoon, 95
Effects of (fold on insects' eggs, 96
Observations of John Hunter, 98
Insects not killed by severe frosts, ib.
CHAPTER V.
Hatching of insect eggs, 100
Structure of the eggs of birds, ib.
Insects do not hatch their eggs, 101
Anomalous instance of the earwig, 102
Earwigs cannot get into the brain, 103
Partial hatching by spiders, 104
Experiments upon the wolf spider by Swammerdam
and Bonnet, 105
Eggs hatched before they are laid, 108
Ovo-viviparous insects, 509
Coil of larvae in the body of a blow-fly, 110
Aphides sometimes produce eggs, sometimes young, 112
CONTENTS. V
Page
Care taken of these eggs by ants, 113
Cocco-viviparous flies (Hippoboscidaz), 116
Effects of heat upon eggs, 118
Management of silk-worms' eggs, 120
Effects of light on eggs, ib.
Some insect eggs increase in size, 121
Growth of the eggs of ants,
Developement of the eggs of spiders,
Spiders live long without food, 124
Insects probably gnaw through their egg-shells, 125
Valves of insect eggs, 126
Period of hatching influenced by temperature, 127
SECTION II. LARVAE.
CHAPTER VI.
Structure of caterpillars, grubs, and maggots, 128
Meanings of these terms, Note, ib.
Supposed transmutation of plants into animals, 129
Observations of Unger upon this, 130
Remarks of Bory St Vincent,
Supposed formative power of the blood, 132
Embryo butterfly in the caterpillar, 133
Experiments to show this, 134
Dissections of the buds of plants, 136
Difference of plants from insects, 137
Internal structure of caterpillars,
Breathing-tubes and formation of their blood, 139
Colours of caterpillars not intended for concealment, 140
Imitative forms of caterpillars, 142
Walking-leaf insect, 144
Caterpillars in form of branches, 146
Conspicuously coloured caterpillars, 147
Butterflies supposed to be coloured like flowers, 149
Singular forms of caterpillars, 151
Forms of water-grubs, 154
Breathing organs in water larvae, 156
Water worms (Nais) may be mistaken for larvae, 159
Syringe for respiration in a water larva, 161
Curious mask of the same larva, 163
Dust mask of the wolf bug (Reduvius), 165
CHAPTER VII.
Growth, moulting, strength, defence, and hybernation of
larvae, 166
Progressive increase of the silk-worm, 167
Compared with the growth of buds, 168
Process of moulting or casting the skin, 169
Accidents interrupt this process, 170
Reds, a disorder similar to renal gravel,
Position of the hairs. in moulting, 173
VOL. VI. B
VI CONTENTS.
Page
Casting of the interior lining of the stomach, &r, 174
Moulting of birds, 176
Cast skins sometimes devoured, 177
Mis-statement of Goldsmith, ib.
Contrivances for escape from confinement, 178
Muscular strength ofinsects, 179
Fleas made to draw miniature coaches, 180
Numerous muscles of the cossus,
Its wonderful strength, 184
Mis-statements respecting the strength ofinsects, 185
Means of escape by spinning, 186
Defensive hairs and spines of caterpillars, 187
Excrementitious covering of some larvae, 190
Origin of the froth on plants called cuckoo-spify 191
Winter covering of caterpillars, 192
Fat a probable defence against cold, 195
CHAPTER VIII.
Voracity of caterpillars, grubs, and maggots, 196
Increase of weight in the silk'wonn in thirty days, 197
Remarkable change in the capacity of the stomach, 198
Instances of human voracity, 201
Jaws or mandibles of larvsR, 202
Caterpillars, ib.
Blight caused by an oak-leaf-roller, 203
Ravages of the buff-tip, 204
Encamping caterpillars of the ermine moths, 205
Experiments with these, 206
Extraordinary ravages of the brown-tail moth, 208
Strange enactment of the Parliament of Paris, 209
Cause of the abundance of caterpillars in particular
years, 210
Alarm caused in France by the gamma moth, 211
Calculation of their fecundity, 212
Cabbage caterpillars prefer weeds, 213
Disappearance of the black-veined white butterfly, 214
Ravages of the caterpillar of the gooseberry saw-fly, 215
Similar ravages committed on other trees, 216
Slug worm of North America, 217
Turnip fly erroneously fancied to come across the sea
to Norfolk, 218
Effects of JEgerise on currant and poplar trees, 220
Destruction of grain by Euplocami and Tinse, 221
Bee-hives injured by Gallarise, 222
Caterpillar which feeds on chocolate, 224
CHAPTER IX.
Voracity of grubs, 225
Grub of the cockchafer or maj-bug, 226
Account of its transformation, &c, 227
CONTENTS. Vll
Page
Methods of destroying,
Wire worm the grub of Hemirhipus,
Probable mistake respecting the destruction of wheat, 231
Pea beetle of North America,
Corn weevil, 234
Meal worm, the grub of Tenebrio molitor, ib.
Tabby moth caterpillar devours butter and fat, 236
Intestinal worms, ib.
Mistakes of Linnaeus, Dr Barry, and Dr J. P. Frank, 237
Experiment of M. Deslonchamps,
Extraordinary case of Mary Riordan, by Dr Pickells, 239
Authenticity of this case proved, 241
Fruit grubs, 242
N ut weevil and its transformations, ib.
Apple-bud weevil, . 243
Voracity of Calosoma, 244
Rayed galleries of a bark-grub, 245
Ravages of locusts, 246
Their swarms in Southern Africa, 247
The Italian locust, 249
Migrations in Palestine and Europe, 250
CHAPTER X.
Voracity of maggots, 252
Maggots of crane flies popularly called the grub, ib.
Remarkable ovipositor, 253
Destruction of herbage on Blackheath, 254
Similar devastations in Poitou and Holderness, 255
Wheat fly, described by Mr Shireff, 256
Additional particulars by Mr Gorrie, 259
Observations ofKirby, 260
Mistake of Mr Markwick, 261
Hessian fly, as described by Mr Say, 262
Cheese-hopper the maggot of Piophila, 263
Wonderful structure of this maggot, 264
Its transformation into a fly, 265
Origin of the house fly (Musca domestica), 266
Mistakes of Ray and Reaumur, 267
Voracity of the maggots of blow-flies, 268
Instance of man devoured by them, \\ 3t
Popular mistake respecting lady-birds, ggg
Thair transformations traced to the egg, 270
Aphides checked by these and by Syrphidae,
SECTION III. PUP^E.
CHAPTER XI.
Mechanism of suspending chrysalides, 272
Proceedings of larvae upon their approaching change, 273
In what manner some caterpillars suspend themselves, 274
Viii CONTENTS.
Page
Their attempts sometimes unsuccessful,
Organ for holding fast,
Suspensory cincture of other caterpillars, 279
Method of forming- this by the swallow-tail, "281
Parchment-like pupa case of flies (Muscidce),
Flask-shaped pupae of Syrphidae, 284
Transformations of a Tipulidan gnat, 285
Mode by which the nymph is suspended, 286
Hooked aquatic pupa (Hydrocampa?)^ 287
CHAPTER XII.
Form and structure of pupae, 288
The term of Metamorphosis objected to, ib.
Harvey's fancies about transmutation, 289
Similar fancies of Goedart exposed by Swammerdam, 290
Structure of the pupa of the chameleon fly, 292
Pupa of the lappit moth, 293
Chrysalis and transformations of the peacock butterfty, 294
Origin of philosophic errors, 296
Changes produced on pupae by evaporation, 297
Objections to the theory of evaporation, 298
Respiratory organs of pupa?, 300
Experiments upon the breathing of pupae, 301
Valves of the spiracles, 302
Breathing apparatus in the pupae of aquatic crane flies
and gnats, 304
Plumed apparatus of the blood-worm, 305
CHAPTER XIII.
Transformation of pupae into perfect insects, 307
Theory of transpiration by means of heat, ib.
Objections to this theory, 308
Experiments by Reaumur, 309
Chrysalides hatched under a hen, 310
Forcing of butterflies in winter, 311
Retarding the evolution of butterflies by cold, 312
Experiments on pupae led to the varnishing of eggs, ib.
Illustrations of torpidity in animals and plants, 313
Various periods of disclosure in the same brood, 314
Supposed final cause of this, 315
Fixed time of the day for some insects to be evolved, 316
Remarkable evolution of the gnat, 317
Still more remarkable instance of the blood-worm, 319
Netted doors in the pupa cases of caddis-flies, 320
Bellows-apparatus in the pupa of the blow-fly, 321
Contrivance in the pupae of wood feeders, 322
Singularity in the locust moth, 323
Ingenious contrivance in a small leaf roller, 324
CONTENTS. IX
Page
Mistake of Bonnet with respect to the teazle-moth, 325
Pupa cases opened by extraneous assistance, 328
Observations on this by the younger Huber, 327
Experiment by Dr J. R. Johnson, 329
De Geer's observations contrary to those of Svvara-
merdam, 330
Remarkable circumstance in the hive bee, 331
SECTION IV. PERFECT INSECTS.
CHAPTER XIV.
Expansion of the body and wings in insects newly trans-
formed, 333
Structure of birds to contain air, ib.
Expansion in the fly of the ant-lion, 334
The mandibles prove it carnivorous, 335
Transformations of dragon-flies, 336
Folded wings of some two winged flies, 338
Malpighrs account of the transformations of the silk-
worm, 339
Impulsion of fluids into the wings, 341
Kirby's account of the expansion of the swallow-tailed
butterfly, 342
Swammerdam's account of the wings of the bee, 343
Air-tubes in insects' wings, 344
Nervures in the wings of plumed moths, 345
Perfect insects do not increase in size, 347
Imperfect insects from fallen chrysalides, 349
Discharges from newly-evolved insects, 350
Supposed showers of blood accounted for, 351
Theories devised to account for crimson-snow, 352
Curious fact explaining this, by Mr T. Nicholson, 354
Does not explain the red snow of the Alps, 355
CHAPTER XV.
Peculiar motions of insects, 356
Motion indispensable to life, ib.
Anecdote of a water-measurer, 357
Mode of combing themselves used by spiders, 358
Oscillatory motions of some tipulidae, 359
Vibratory motions of syrphi on the wing, 360
Similar motions of hawks, red-breast, &c, 361
Experiment on Scioptera vibrans^ 362
Illustrated by the wag-tail, &c, 363
Gnat dances in winter, ib.
Opinion of Wordsworth and others, 364
Similar aerial dances of rooks, ib.
Night-gambols of Corethrce ? on a book, 365
Circular movements of a summer fly, 366
Sportive movements not necessarily social, 367
Account of the whirlwig, by Kirby and by Knapp, ^ 36&
VOL. VI. B*
X CONTENTS.
Page
Remarkable structure of its eyes,
Battles of butterflies,
Choral assemblies of ephemeridae, 273
Account of these by Reaumur, ib.
Sports of ants, 376
GjTnnastics of ants, according to Huber, 377
CHAPTER XVI.
Peculiar locomotions of insects,
Examples from quadrupeds, ib.
Singular movements of some plant-bugs, 380
Sailing of the whirlwig beetle,
Walking on water by spiders, &c,
Walking through water by aquatic mites,
Oblique pace of midges,
Insect with its legs on its back,
Rapid galloping of the strawberry mite, 386
Slow movements of the oil-beetles,
Supposed sponges in the foot of the fly, 388
Correct notions of Derham and White, proved by Sir
E. Home,
Apparatus in the feet of flies,
Leaping muscles of the flea,
Leaping of grasshoppers and Springtails,
Springing of spiders on their prey, 394
Flight of insects, 395
Mechanism of insects' wings and their muscles, ac-
cording to M. Chabrier, 396
Flying of spiders without wings, 397
CHAPTER XVII.
Rest of insects, 399
.Night insects rest in the day, ib.
Day movements of other insects, 400
Insects have no brain nor spinal cord, ib.
Want also a proper heart as well as blood, 401
Supposed pulse in insects, ib.
No circulation, 402
Alleged discovery of an insect circulation, by Dr
Carus, ib.
How the circulation is affected in the sleep of man, 404
The same effects cannot take place in insects, 405
Sleep of senses not equally profound, 406
Torpidity of insects in winter, ib.
Hybernation of ants, 407
Anecdotes from Huber, 408
Hibernation of bees, 410
Discrepancies of opinion among naturalists 413
Hybernation of the hearth cricket, 414
ILLUSTRATIONS.
Page
1. Comparative figures of a bee and a syrphus, 4
2. Cell of a queen of the Termites bellicosi, broken
open in front; the labourers surrounding the queen,
and carrying off the eggs, 15
3. Groups of eggs of the rose-leaf roller on a pane of
glass, 20
4. Plants of sphcerobulus, natural size, 26
5. Ditto, magnified view, ib.
6. Ditto, sectional view, with the seed just previous to
projection, ib
7. Ditto, with the seed in the act of projection, ib.
8. Ditto, immediately after projection, ib.
9. Microscopic views of applo and pear mould, 30
10. Eggs of a butterfly and of a moth, magnified, 41
11. Magnified egg of the angle-shades moth, 42
12. Sea egg, natural size, ib.
13. Rgg of the meadow brown butterfly, magnified, 43
14. Egg of the brimstone moth, magnified, ib.
15. Dung-fly, with its eggs magnified, and mode of depo-
sition, 44
16. Lace-winged fly, and position of its eggs on a twig of
lilac, 45
17. Ichneumon fly, with its ovipositor, magnified, 57
18. Ichneumon flies ovipositing, 58
19. Generation of ichneumons, seven figures, 62
20. Magnified view of a parasite fly (Evania apendi-
g aster) , 66
21. Bee parasite (Stylops Melitta}, 67
22. Leaf-mining maggots and fly, four figures, 70
23. Gnats forming their egg-boats, 74
Xli ILLUSTRATIONS.
Page
24. Magnified view of the boat of gnats' eggs, 75
25. Female gypsey moths, and modes of depositing their
eggs, four figures, 81
26. Females of the brown and gold-tailed moths, two
figures, 83
27. Tweezers of the brown and gold-tailed moths, mag-
nified, two figures, 84
28. Spiral groups of eggs of an unknown moth, 85
29. Eggs of the lackey moth wound spirally round a twig
of hawthorn, natural size and magnified, two figures, 86
30. Eggs of the coccus, covered with down, and with the
bodies of the mothers, 89
31. Magnified cochenille insects, male and female, two
figures, ib.
32. Eggs of the hawthorn coccus, covered by the body of
the dead mother, 91
33. Ditto, one of these magnified, ib.
34. Section of ditto, showing the eggs within, ib.
35. Suspended spiders' nests, three figures, 94
36. Vapourer moth, male and female, and deposition of
eggs, three figures, 95
37. Drum of the ear, showing that there is no passage
through it to the brain, 103
38. Chequered blow fly, 1 10
39. Abdomen of ditto, opened and magnified, showing
the coil of young larvae, ib.
40. Coil of larvae of ditto, partly unwound, ib.
41. Large gray blow-fly, with the abdomen opened, show-
ing the young maggots, 111
42. Breathing apparatus of the maggot of a large gray
blow-fly, ib.
43. Spider flies, two figures > 117
44. Generation of a water-mite, four figures, 121
45. Hatching of the egg of the garden spider, four figures, 1 24
46. Egg of the privet hawk moth, magnified, showing the
inclosed embryo, 125
47. Caterpillar of ditto, when grown, ib.
48. Construction of eggs to facilitate the escape of the
larvas, three figures, 126
49. Supposed animal and vegetable metamorphoses, 131
50. Egg of the large cabbage butterfly, 133
5 i . Embryo butterflies as they appear in the bodies of ca-
terpillars, two figures, 135
52. Female of the perfect cabbage butterfly, ib.
53. Magnified view of a section of the bud of a laburnum, 1 36
ILLUSTRATIONS. Xlli
Page
54. Section of a bean-seed, 136
55. Seed-leaves, root, and first true leaf of the beech, ib.
56. Dissection of the water-grub of a May-fly, 139
57. Caterpillars of the Clifden nonpareil feeding on the
gray poplar, 142
58. Ditto, in a more advanced stage of growth, 143
59. Walking-leaf insect magnified, 144
60. Transformations of the brimstone moth, 145
61. Caterpillars of the swallow-tailed moth, 146
62. A two-winged fly ( Volucella plumat a), 149
63. Transformations of the puss moth, 152
64. Lobster caterpillar, 153
65. Aquatic grubs of gnats in a glass vessel of water, 155
66. LarvsB of the common-gnat, floating in water, two
figures, 156
67. Buoy-like structure in the tail of a water-grub of a
two-winged fly, 157
68. Telescopic-tailed water-larvae, three figures, 158
69. Water-worms, two figures, 159
70. Grub of the dragon-fly, and various parts of its body
magnified, five figures, 162
71. Mask of the dragon-fly grub, four figures, 164
72. Moulting of caterpillars, and magnified views of parts,
ten figures, 172
73. Exuvia and pulmonary vessels of the rhinoceros beetle, 175
74. Goat moth caterpillar escaping from a drinking-glass , 178
75. Magnified view of the dorsal muscles of the upper half
ofthecossus, 182
76. Caterpillar of cossus escaping from under a loaded
glass, 184
77. Methods used by spiders and caterpillars for ascending
their threads, 186
78. Caterpillar of the tiger-moth, two figures, 187
79. Grub of the museum beetle, natural size and magni-
fied, two figures, ib.
80. Tail of ditto, magnified, ib.
81. Hairs of ditto, magnified, two figures, ib.
82. Thorny hairs of caterpillars, three figures, 189
83. Green tortoise beetle (Cassida equestris), 191
84. Grub of ditto, magnified, to show its anal forks, ib.
85. Grub of ditto, with its canopy of excrements, ib.
86. Spit frog-hopper, and froth covering the grub of the
same, two figures, 192
87. Caterpillar of the drinker moth, two figures, 194
88. Caterpillar of the angle-shades moth, ib.
XIV ILLUSTRATIONS.
89. Moth of ditto, 194
90. Viscera of the cossus, two figures,
91. Caterpillar of Vanessa urtica, magnified, 200
92. Intestines of ditto, ib.
93. Intestinal canals of the caterpillar, pupae, and butter-
, fly, five figures,
94. Buft-tip caterpillar, and moth of ditto, two figures, 204
95. Encampment of the caterpillar of the small ermine
on the Siberian crab,
96. Transformations of the gamma moth, five figures, 212
97. Saw-fly of the gooseberry, and caterpillars, four
figures, 214
98. Caterpillar of the saw-fly (Nematus Caprea) on
the osier, 217
99. Caterpillar of the saw-fly (Selandria alni) on the
alder, ib.
100. Transformations of the grain moth, seven figures, 221
101. Transformations of the honeycomb moth, seven
figures, 223
102. Transformations of the cockchafer, nine figures, 227
103. Wire-worm and click beetle, 230
104. Zabrus gibbus, 231
105. Melolontha ruficornis, ib.
106. Corn weevil, 234
107. Meal-worm, and the beetle produced from it, 235
108. Transformations of the tabby moth, six figures, 236
109. Intestinal worms, three figures, 239
110. Churchyard beetle, in the grub and perfect state,
four figures, 241
111. Nut and apple-tree beetles, eight figures, 243
112. Bark mined in rays by beetle grubs, 245
113. Locust, 251
114. Ovipositor and eggs of the crane-fly, 253
115. Crane fly ovipositing, and the larva beneath in the
earth feeding upon grass roots, 254
116. Germination of a grain of wheat, 259
117. Transformation of the wheat-fly, three figures, 260
118. The Hessian fly, 261
119. The Markwick fly, ib.
120. Transformations of the cheese-hopper, seven figures, 265
121. Transformations of Bibio hortulanus, six figures, 267
122. Transformations of the lady-bird, six figures, 270
123. Transformations of the lace-winged fly and syrphus,
five figures, 271
124. Caterpillar of Vanessa Jlntiopa, three figures, 274
ILLUSTRATIONS. XV
125. Suspended caterpillar of Vanessa JLntiopa splitting
its skin for the evolution of the chrysalis, four
figures, 276
126. Chrysalides of Vanessa urticce suspended, with the
anal hooks magnified, and old skin fallen off, four
figures, 278
127. Black-veined white butterfly, caterpillar, and chry-
salis, three figures, 280
128. Caterpillar and chrysalis of swallow-tailed butterfly,
three figures, 281
129. Pupae of blow-fly and syrphus, four figures, 284
130. Transformations of the gnat (Corethra plumicor-
ms), six figures, 287
131. Pupa of chameleon fly, three figures, 292
132. Pupa of lappit moth, three figures, 294
133. Chrysalis of Gonepteryx Rkamni, 300
134. Pupa of Laria fascelina, ib.
135. Pupa of Sphinx Ligustri, ib.
136. Spiracles of pupae, two figures, 302
137. Pupae of the gnat and Tipula , four figures, 304
138. Transformations of Chironomus plumosus, four
figures, 305
139. Case fly, with the pupa, and the grate-works of the
opening of the latter, four figures, 321
140. Pupas of Cossus and JEgeria, 323
141. The fly and pupa of the ant-lion, four figures, 335
142. Transformation of the dragon-fly, five figures, 337
143. Blow-fly, magnified, two figures, 338
144. Wings of insects, showing the nervures, six figures, 344
145. Twenty-plume moth, two figures, 345
146. White-plume moth, ib.
147. Specimens of deformed butterflies and moth, three
figures, 350
148. Red spider, and the head, magnified, two figures, 359
149. Head of the garden spider magnified, ib.
150. Phalangium, 360
151. Hydrometra stagnorum, magnified, ib.
152. Ploiaria vagabunda, magnified, 381
153. Neides elegans, magnified, ib.
154. Hydrometra stagnorum, natural size, 382
155. Hydrachna geographica, magnified, two figures, ib.
156. Velia rivulorum, ib.
157. Julus terrestris, two figures, 386
158. Oil-beetle, ib.
Xvi ILLUSTRATIONS.
159. Nycteribia Hermanni, 386
160. Feet of the fly, greatly magnified, four figures, 391
161. Flea, magnified, 392
162. Velvet spring-tail, magnified, 394
163. American spider (Mygale avicularia) destroying
a bird, 395
164. Muscular ribbons for moving the wings in Syrphus
inanis, magnified, two figures, 397
165. Syrphus, 398
INSECT TRANSFORMATIONS.
SECTION I. EGGS OF INSECTS.
CHAPTER I.
All Insects come frdm Eggs as Plants do from Peeds. Vulgar errors of
Insects being generated by Putrefaction and Blighting Winds disproved
by experiment.
IT was universally believed by the ancient philoso-
phers, that n.aggots, flies, and other insects were
generated from putrefying substances. This opinion
continues to be held by uninformed persons among
ourselves; though it would be equally correct to
maintain, that a flight of vultures had been generated
by the dead carcass which they may be seen devour-
ing, or a flock of sheep from the grass field in which
they graze. Another opinion, perhaps still more gene-
rally diffused, is that caterpillars, aphides, and other
garden insects which destroy the leaves of plants, are
generated, propagated, or, at least, spread about, by
certain winds or states of the air, mysteriously and
indefinitely termed blight. The latter belief is, pro-
bably, not so easy of immediate refutation as the for-
mer; but, as we shall endeavour to show, it seems
to us to be equally erroneous.
The small size of insects renders it somewhat easy
to pass off fanciful opinions regarding them, since it
is difficult for common observers to detect mistakes,
VOL. vi. 1
2 INSECT TRANSFORMATIONS.
but similar notions have been entertained by writers
of no mean reputation, respecting even the larger
animals. The celebrated Kircher, for example, one
of the most learned men of the seventeenth century,
goes so far as to give the following singular recipe for
the manufacture of snakes :
f Take some snakes,' says he, c of whatever kind
you want, roast them, and cut them in small pieces,
and sow those pieces in an oleaginous soil; then,
from day to day, sprinkle them lightly with water
from a watering-pot, taking care that the piece of
ground be exposed to the spring sun, and in eight
days you will see the earth strewed with little worms,
which, being nourished with milk diluted with
water, will gradually increase in size till they take
the form of perfect serpents. This,' he subjoins
with great simplicity, I learned from having found
in the country the carcase of a serpent covered with
worms, some small, others larger, and others again
that had evidently taken the form of serpents. It
was still more marvellous to remark, that among
these little snakes, and mixed as it were with them,
were certain flies, which I should take to be engen-
dered from that substance which constituted the
aliment of the snakes.'*
Kircher's more shrewd and less fanciful cor*
respondent, Redi, determined to prove this singular
recipe before he trusted to the authority of his friend.
< Moved,' he says, c by the authentic testimony of
this most learned writer, I have frequently tried the
experiment, but I could never witness the genera-
tion of those blessed snakelets made to hand.|'
But though Redi could not, in this way, produce a
brood of snakes, his experiments furnished an
abundant progeny of maggots, the same, unques-
* Athan. Kircher, Mund. Subterran. lib. xii.
t Redi, Generat. Insectorum, edit, Amstel. 1686.
GENERATION OF INSECTS. O
tionably, that the imagination of Kircher had magni-
fied into young snakes, which, being confined in
a covered box, were in a short time transformed into
flies, at first of a dull ash. colour, wrinkled, un-
finished, and their wings not yet unfolded, as is
always the case with winged insects just escaped
from their pupa case. In less than an hour, how-
ever, they ' unfolded their wings, and changed into
a vivid green, marvellously brilliant ' most proba-
bly the green flesh-fly (Musca Ccesar. LINN.)
It is a common opinion in this country, particu-
larly in the north, that if a horse's hair be put into
the water of a spring or a ditch, it will be in process
of time transformed, first into a hair-worm, and after-
wards into an eel. The deception, as in the instance
of Kircher's snakes, arises from the close resemblance
between a hair and the hair-worm ( Gordius aquati-
cus, LINN.), and between this and a young eel. This
fabled transformation of hair, which we have heard
maintained even by several persons of good educa-
tion, is physically impossible and absurd.
The method laid down by Virgil in his Georgics
for generating a swarm of bees is precisely of the
same description as the snake recipe of Kircher; and
though the c Episode of Aristseus recovering his bees '
has been pronounced to be ' perhaps the finest piece
of poetry in the world,' we must be permitted to say
that it is quite fabulous and unphilosophical. The
passage runs thus :
Oft from putrid gore of cattle slain
Bees have been bred. * * * A narrow place,
And for that use contracted, first they choose.
Then more contract it, in a narrower room,
Wall'd round, and cover'd with a low built roof,
And add four windows, of a slanting light
From the four winds. A bullock then is sought 4
His horns just bending in their second year;
4 INSECT TRANSFORMATIONS.
Him, much reluctant, with o'erpow'ring force,
They bind; his mouth and nostrils stop, and all
The avenues of respiration close;
And buffet him to death: his hide no wound
Receives; his battered entrails burst within.
Thus spent they leave him; and beneath his sides
Lay shreds of boughs, fresh lavender and thyme.
This, when soft zephyr's breeze first curls the wave,
And prattling swallows hang their nests on high.
Meanwhile the juices in the tender bones
Heated ferment; and, wondrous to behold,
Small animals, in clusters, thick are seen,
Short of their legs at first: on filmy wings,
Humming, at length they rise; and more and more
Fan the thin air; 'till, numberless as drops
Pour'd down in rain from summer clouds, they fly.'
TRAPP'S VIRGIL, Georg. iv, 369.
Columella, a Roman writer on rural affairs, after
directing in what manner honey is to be taken from
a hive by killing the bees, says, that if the dead bees
be kept till spring, and then exposed to the sun among
the ashes of the tig-tree, properly pulverised, they may
be restored to life.
These fancies have evidently originated from mis-
taking certain species of flies (Syrphi, Bombylii,
&c,) for bees, which, indeed, they much resemble in
general appearance ; though they have only two
wings, and short antenna?, while all bees have four
wings, and long antennae. Neither the flies nor the
b
Comparative figures of a bee (a) and a syrplms (b).
bees are produced by putrefaction; but as the flies
are found about animal bodies in a state of decom-
position, the ancients fell into an error which accurate
observation alone could explode. The maggots of
GENERATION OF INSECTS. 5
blow-flies, as Swammerdam remarks, so often found
in the carcasses of animals in summer, * somewhat
resemble those produced by the eggs of bees. How-
ever ridiculous,' he adds, c the opinion must appear,
many great men have not been ashamed to adopt and
defend it. The industrious Goedart has ventured to
ascribe the origin of bees to certain dunghill worms,*
and the learned De Mei joins with him in this opi-
nion; though neither of them had any observation to
ground their belief upon, but that of the external re-
semblance between bees and certain kinds of flies
(Syrphidce) produced from those worms. The mis-
take of such authors should teach us,' he continues,
* to use great caution in our determinations concern-
ing things which we have not thoroughly examined,
or at least to describe them with all the circum-
stances observable in them. Therefore, although
this opinion of bees issuing from the carcasses of
some other animals by the power of putrefaction,
or by a transposition of parts, be altogether absurd,
it has had, notwithstanding, many followers, who
must have in a manner shut their eyes in order to
embrace it. But whoever will attentively consider
how many requisites there are for the due hatching
of the bee's egg, and for its subsistence in the grub
state, cannot be at a loss for a clue to deliver him-
self out of that labyrinth of idle fancies and unsup-
ported fables, which, entangled with one another like
a Gordian knot, have even to this day obscured the
beautiful simplicity of this part of natural history. 'f
Redi was by no means satisfied with the first re-
sults of his experiments upon the flesh of snakes, for
* The maggots of Eristalis tenax, FABR. E. apiformis,
MEIGEN, and other Syrphida, well known in common sew-
ers by their long tails, like those of rats.
t Swammerd. Book of Nature, i, 228.
VOL. VI. 1*
6 INSECT TRANSFORMATIONS.
several species of flies were produced, giving some
countenance to the opinion of Aristotle, Pliny, Mouf-
fet, and others, that different flesh engenders different
flies, inheriting the disposition of the animal they are
bred from. He accordingly tried almost every
species of flesh, fish, and fowl, both raw and cooked,
and soon discovered (as he could not fail to do) that
the same maggots and flies were produced indis-
criminately in all. This ultimately led him to
ascertain that no maggots are ever generated except
from eggs laid by the parent flies: for when he
carefully covered up pieces of meat with silk or
paper sealed down with wax, no maggots were
seen; but the parent flies, attracted by the smell of
the covered meat, not unfrequently laid their eggs
on the outside of the paper or silk, the maggots
hatched from these dying, of course ? for want of
nourishment.
With respect to bees, it becomes even more absurd
to refer their generation to putrefaction, when we
consider that they uniformly manifest a peculiar
antipathy to dead carcasses. This was remarked so
long ago as the time of Aristotle and of Pliny ;*
and Varro asserts that bees never alight upon an
unclean place, nor upon any thing which emits an
unpleasant smell. This is strikingly exemplified in
their carrying out of the hive the bodies of their
companions who chance to die there; and in their
covering over with propolis the bodies of snails,
mice, I and other small animals which they cannot re-
move. J
These facts, which are unquestionable, may at
first view appear to contradict the Scripture history
* Aristotle, Hist. Animal, ix, 40. Pliny says, ' Ornnes car-
ne vescuntur, contra quarn apes, quae nullum corpus aitingunt*
t Huish on Bees, p. 100.
i Insect Architecture, p. 109.
GENERATION OF INSECTS. 7
of Sarnson, who, having killed a young lion in the
vineyards of Timnath, * after a time turned aside to
see the carcass of the lion: and behold a swarm of
bees and honey in the carcass.'* It only requires
us, however, to examine the facts, to show that
this does not disagree with the preceding statement.
Bochart, in his Sacred Zoology, tells us that the
word rendered ' carcass' literally signifies skeleton;
and the Syriac version stilt more strongly renders
it a dried body (corpus exsiccatum). Bochart fur-
ther contends, that the phrase ' after a time' is one
of the commonest Hebraisms for a year. But when
we consider the rapid desiccation caused by the sum-
mer suns of Palestine, this extension of time will be
unnecessary; for travellers tell us that the bodies of
dead camels become quite parched there in a few
days. We have the testimony of Herodotus, that a
swarm of bees built their cells and made honey in
the dried carcass of a man placed above the gate of
Athamanta. Soranus also tells us of a swarm of
bees found in the tomb of the celebrated Hippocrates.
' I have been told,' says Redi, < by Albergotto, a
man of profound erudition, that he had seen a swarm
in the cranium of a horse. Bees,' he adds, c not
only do not live upon dead bodies, but they will not
even come near them, as I have often proved by ex-
periment.' ' It is probable,' says Swammerdam,
that the not rightly understanding Samson's ad-
venture of the lion gave rise to the popular opinion
of bees springing from dead lions, oxen, and horses.'
Kirby and Spense seem disposed to consider Sam-
son's bees, as we have done those of Virgil, to be
flies resembling bees; but the ' honey' which Samson
< took in his hands and went on eating,' is fatal to
such an exposition.
The ancients had. another fancy respecting the
* Judges, xiv, 8.
8 INSECT TRANSFORMATIONS.
propagation of bees, equally absurd, though much
more poetical. Virgil tells us that,
From herbs and fragrant flowers, with their mouths
They cull their young. Georg. iv.
Aristotle* had long before stated, and De Monfort
in modern times repeated the assertion,! that the
olive, the cerinthus, and some other plants, have the
property of generating young bees from their purest
juices. We may well say, with Lactantius, that
' they make shipwreck of their wisdom, who adopt
without judgment the opinions of their ancestors,
and allow themselves to be led by others like a flock
of sheep. 'J Modern naturalists, being accustomed
to minute accuracy in their observations, can both
disprove and readily explain most of those erroneous
fancies, by tracing the causes which led, and may still
lead, inaccurate observers into such mistakes.
It would have been well if such unfounded fancies
had rested here; but philosophical theorists, both of
ancient and modern times, have promulgated dreams
much more extravagant. The ancients taught that
the newly-formed earth (hatched as some said from
an egg) clothed itself with a green down like that
on young birds, and soon after men began to sprout
up from the ground as we now see mushrooms do.
The refined Athenians were so firmly convinced of
their having originally sprung up in this manner,
that they called themselves 4 Earth-born' (Erich-
thonii), and wore golden tree-hoppers (Cicadai) in
their hair, erroneously supposing these insects to
have a common origin with themselves. Lucretius
* Hist. Animal, v, 22.
t Le Portrait de la Mouche a Miel. Liege, 1646.
t Divin. Instit. ii, 7; in Redi's motto. Shepherds on the
continent lead their sheep, as those of Israel did. See Mena-
geries, vol. i, p. 81.
The Cicadae do not deposit their eggs in the earth, but on
trees, &c. See Insect Architecture, chap. vii.
GENERATION OF INSECTS. 9
affirms, that even in his time, when the earth was sup-
posed to be growing too old to be reproductive, c many
animals were concreted out of mud by showers and
sunshine.'*
But the ancients, it would appear, had the shrewd-
ness seldom to venture upon illustrations of their phi-
losophical romances by particular examples. This was
reserved for the more reckless theory-builders of our
own times. We find Robinet, for example, asserting
that, as it was nature's chief object to make man, she
began her * apprentissage,' as he calls it, by forming
minerals resembling the single organs of the human
body, such as the brain in the fossil called Brain-stone
(Meandrina certbriformis, PARKINSON.)! Darwin,
again, taking the hint from Epicurus, dreams that an-
imals arose from a single filament or threadlet of mat-
ter, which, by its efforts to procure nourishment,
lengthened out parts of its body into arms and other
members. For example, after this filament had im-
proved itself into an oyster, and been by chance left
dry by the ebbing of the tide, its efforts to reach the
water again expanded the parts nearest to the sea in-
to arms and legs. If it tried to rise from its native
rocks, the efforts produced wings, and it became an
insect, which in due course of time improved itself
by fresh efforts till it became a bird, the more perfect
members being always hereditarily transmitted to the
progeny. The different forms of the bills of birds,
whether hooked, broad, or long, were, he says, gradu-
ally acquired by the perpetual endeavours of the crea-
tures to supply their wants. The long-legged water-
* Multaque nunc etiam existunt animalia terris,
Imbribus et calido soils concreta vapore.
JDe Nat. Rer. v, 795.
t Robinet, Consid. Philosophiques dela Gradation Naturelle
<Jes Formes de 1'Etre. Paris, 1768.
10 INSECT TRANSFORMATIONS.
fowl (Grallatores, VIGORS) in this way acquired
length of legs sufficient to elevate their bodies above
the water in which they waded. c A proboscis,' he
says, e of admirable structure has thus been acquired
by the bee, the moth, and the humming-bird, for the
purpose of plundering the nectaries of flowers.'* La-
marck, an eminent French naturalist, recently deceas-
ed, adopted the same visions; and, among other illus-
trations of a similar cast, he tells us that the giraffe
acquired its long neck by its efforts to browse on the
high branches of trees, which, after the lapse of a few
thousand years, it successfully accomplished.
Theories like the preceding all originate in the en-
deavours of human ingenuity to trace the operations
of nature farther than ascertained facts will warrant ;
and the necessary blanks in such a system, which
presupposes much that cannot be explained, are filled
up by the imagination. This inability to trace the
origin of minute plants and insects led to the doctrine
of what is called spontaneous or equivocal generation,
of which the fancies above-mentioned are some of the
prominent branches. The experiments of Redi on
the hatching of insects from eggs, which were pub-
lished at Florence in 1668, first brought discredit up-
on this doctrine, though it had always a few eminent
disciples. At present it is maintained by a consider-
able number of distinguished naturalists, such as
Blumenbach, Cuvier, Bory de St Vincent, R.
Brown, &c. c The notion of spontaneous genera-
tion,' says Bory, is at first revolting to a rational
mind, but it is, notwithstanding, demonstrable by the
microscope. The fact is averred: Miiller has seen
it, I have seen it, and twenty other observers have
seen it : the Pandorinia exhibit it every instant. 'f
* Darwin's Zoonomia, sect, xxxix, 3d edit. London, 1801.
t Diet. Classique d'Hist. Nat., Art. Microscopiques, p, 541.
GENERATION OF INSECTS. 1 1
These pandorinia he elsewhere describes as probably
nothing more than ' animated scions of Zoocarpae'
(propagules animes des Zoocarpes.)* It would be
unprofitable to go into any lengthened discussion upon
this mysterious subject ; and we have" great doubts
whether the ocular demonstration by the microscope
would succeed except in the hands of a disciple of the
school. Even with naturalists, whose business it is to
deal with facts, the reason is often wonderfully influ-
enced by the imagination.
But the question immediately before us happily does
not involve these recondite discussions ; for if even
pandorinia and other animalcules were proved beyond
a doubt to originate in the play of chemical affinities
or galvanic actions (a more refined process, it must
be confessed, than Kircher's chopped snakes), it would
not affect our doctrine that all insects are hatched from
eggs : for no naturalist of the present day classes
such animalcules among insects. Leaving animal-
cules and zoophytes, therefore, out of the question,
we have only to examine such branches of the theory
of spontaneous generation as seem to involve the pro-
pagation of genuine insects, like the fancies about
putrefaction which we have seen refuted.
The notion that small insects, such as aphides
and the leaf-rolling caterpillars, are spread about, or
rather generated, by what is termed blight (possibly
from the Belgic blinkan, to strike with lightning), is
almost universally believed even by the most intel-
ligent, if they have not particularly studied the hab-
its of insects. Mr Main, of Chelsea, an ingenious
and well-informed gardener and naturalist, describes
this as an ' easterly wind, attended by a blue mist.
The latter is called a blight, and many people
imagine that the aphides are waited through the
* Diet. Class., Art. Pandoriir'es.
12 INSECT TRANSFORMATIONS.
air by this same mist.'* c The farmer,' says Keith,
1 supposes these insects are wafted to him on the
east wind, while they are only generated in the ex-
travasated juices as forming a proper nidus for their
eggs. 'I A more detailed account, however, is given
by the late Dr Mason Good, and as he speaks in
part from personal observation, and was not only
one of the most learned men of his time, but an ex-
cellent general naturalist, his testimony merits every
attention :
* That the atmosphere,' says Dr Good, ( is freight-
ed with myriads of insect eggs that elude our senses,
and that such eggs, when they meet with a proper bed,
are hatched in a few hours into a perfect form, is clear
to any one who has attended to the rapid and wonder-
ful effects of what, in common language, is called a
blight upon plantations and gardens. 1 have seen, as
probably many who read this work have also, a hop-
ground completely overrun and desolated by the aphis
humuli, or hop green-louse, within twelve hours after
a honey-dew (which is a peculiar haze or mist loaded
with poisonous miasm) has slowly swept through the
plantation, and stimulated the leaves of the hop to the
morbid secretion of a saccharine and viscid juice,
which, while it destroys the young shoots by exhaus-
tion, renders them a favourite resort for this insect,
and a cherishing nidus for myriads of little dots that
are its eggs. The latter are hatched within eight and
forty hours after their deposit, and succeeded by hosts
of other eggs of the same kind; or, if the blight take
place in an early part of the autumn, by hosts of the
young insects produced viviparously; for, in different
seasons of the year, the aphis breeds both ways.
Now it is highly probable that there are minute
* Loudon's Mag. of Nat. Hist, i, 180.
f Keith's Physiological Botany, ii, 486.
GENERATION OF INSECTS. ' 13
eggs or ovula, of innumerable kinds of animalcules
floating by myriads of myriads through the atmo-
sphere, so diminutive as to bear no larger proportion
to the eggs of the aphis than these bear to those of
the wren or the hedge-sparrow; protected at the
same time from destruction, by the filmy integument
that surrounds them, till they can meet with a proper
nest for their reception, and a proper stimulating-
power to quicken them into life; and which, with
respect to many of them, are only found obvious to the
senses in different descriptions of animal fluids.'*
It appears to us that it can be nothing more than
a fancy, which is quite unsupported by evidence, to
say that the ejjfr of any species of animalcules or
insects float about in the atmosphere; for, independent
of their weight, (every known species being greatly
heavier than air,) the parent insects of every species
whose history has been accurately investigated mani-
fest the utmost anxiety to deposit their eggs upon or
near the appropriate food of the young. To commit
them to the winds would be a complete dereliction of
this invariable law of insect economy, But admit-
ting for a moment this hypothesis that the eggs of
insects are diffused through the atmosphere, the cir-
cumstance must be accompanied with two conditions,
the eggs must either be dropped by the parents
while on the wing, or be carried off by winds from the
terrestrial substances upon which they may have been
deposited.
On the supposition that the eggs are dropped by the
mother insects while on the wing, we must also admit
(for there is no avoiding it) that they continue to
float about, unhatched, from the end of the summer
till the commencement of spring, at which time only
the broods make their appearance. Yet when we
* Good's Study of Medicine, v. i, p. 339, 3rd edition, Lon-
don, 1829.
VOL. VI. 2
14 INSECT TRANSFORMATIONS.
consider the rains, snows, and winds, to which they
must be exposed for six or nine months, we think
the hardest theorist would scarcely maintain that a sin-
gle egg could out -weather these vicissitudes, and con-
tinue to float in the air. It may not be out of place
to remark, that the female aphides, which deposit eggs
in autumn, have no wings.
Again, on the supposition that the eggs are de-
posited on plants, trees, or other objects, it is still
more unlikely that they could be carried into the air;
for, on exclusion, they are, with very few exceptions,*
enveloped in an adhesive cement which glues them
to the spot on which they are deposited. When
eggs are deposited singly, this cenjj^; usually enve-
lopes each with a thin coating, as in the instance of
the admirable butterfly (Vanessa Jltalanta); but
when they are placed in a group the cement is some-
times spread over the whole, as in the instance of the
white satin moth (Leucoma salicis, STEPHENS),
This cement is evidently intended by Nature (who
seldom accommodates her plans to our theories) to
prevent the eggs from being carried from the place se-
lected by the mother insect for their deposition. Those
eggs, therefore, which are placed on the outside of
substances, have this provision for their secure attach-
ment to the locality chosen by the instinct of the mother.
But, on the contrary, the principle does not always
hold in the case of those deposited in nests and exca-
vations, and particularly as to those of ants arid ter*
mites. The working ants, indeed, carry the eggs from
the top to the bottom of their galleries, according as
the weather is favourable or unfavourable for hatching.
The labourers of the white ants (Termites), again, at-
tend their queen with the utmost care when she is lay-
ing; for as she cannot then move about, they are under
the necessity of carrying off the eggs, as they are Iaid 3
* Latreille, Hist. Gener, xiv, p. 342.
GENERATION OF INSECTS. 15
to the nurseries. The extraordinary labour which this
requires in the community may be understood, when,
according to Smeathman, she lays 60 eggs in a minute,
which will amount to 86,400 in a day, and 31,536,000
in a year. The exceptions now mentioned, howev-
er, do not in the least invalidate our general posi-
tion.
Cell of a queen of the Termites bellicosi, broken open in front ; the
labourers surrounding the queen and carrying off her eggs.
Another no less remarkable circumstance is the
great weight, or specific gravity, of the eggs of in-
sects. From numerous experiments we may venture
to say that those of all the species which we have
tried sink rapidly in water the moment they are
thrown into it, from the egg of the drinker moth (Odo-
nestis Potatoria, GERMAR), which is nearly as large
as a hemp-seed, to that of the rose-plant louse (Aphis
rosce\ which is so small as to be barely visible to the
naked eye. Some eggs of the gipsey moth (Hypo-
gymna dispar, STEPHENS), indeed, floated in water,
because they were covered with down. It is well
known, as we shall presently show, that the diffu-
sion of many of the seeds of plants is accomplished
by the winged down with which they are clothed;
16 INSECT TRANSFORMATIONS.
but the down upon the eggs of insects does not con-
duce to this end. Whether insect eggs be naked or
clothed with down, they are invariably, as far as their
history has been investigated, deposited close to or
upon substances capable of affording food to the young
when hatched. In making experiments upon the spe-
cific gravity of eggs, it should be remembered that
no infertile or unimpregnated egg will sink; for having
some hundreds of these laid by different species of
insects reared in our cabinet, we found, upon trial,
that they uniformly floated, while those which we knew
to be impregnated as uniformly sunk. A female, for
example, of the rose-leaf roller (Lozolcenia Rosana,
STEPHENS) was reared by us, in solitude, under an
inverted wine-glass, upon the side of which she glued
a patch of eggs, of course, unimpregnated: these,
upon trial, all floated in water. But eggs of the same
species taken from the outside of a pane of glass
close to a rose-tree, all sunk in water; and it is to be
fairly presumed, as the parent of the latter was in a
state of freedom, that these were impregnated. We
found the same distinction, indeed, to hold in the eggs
of the drinker moth, the gypsey moth, and numerous
other insects. *
Dr Good's account of ( honey-dew,' which he des-
cribes as c a peculiar haze or mist loaded with a poi-
sonous miasm,' that stimulates < the leaves of the hop
to the morbid secretion of a saccharine and viscid
juice' appears to us unsupported by facts. Lin-
naeus,f on the contrary, who was not wedded to the
meteorological theory of a miasmatous haze, ascribes
the honey-dew on the hop leaves to the caterpillar of
the ghost moth (Hepialus humuli) attacking the roots.
Dr Withering, favouring this account, recommends
covering the roots with stones as a preventive; for
* J. R. t Quoted by Keith, Phys. Bot. ii, 143.
GENERATION OF INSECTS. 17
the caterpillars, he avers, never attack wild hops
which grow in stony places, because they cannot
get at the roots.* It appears to us, however, that
there can be little doubt that the sweet syrupy
coating, called honey-dew 3 found on the leaves of
the hop, is nothing more than the excrement of
the insect (Jlphis humuli) whose propagation we
are discussing. ' The honey-dew,' says Loudon,
' mostly' (we believe always) c occurs after the crops
have been attacked by these insects.'! Sir J. E.
Smith, who admits this to be the common cause of
honey-dew, contends that what is found on the leaves
of the beech is an exception; but he adduces no evi-
dence at all satisfactory in proof of its being caused
by unfavourable winds ;| while the undoubted fact of
its being the excrement of aphides in so many other
instances^ weighs strongly against him.
A novel theory of honey-dew has just been pub-
lished by Mr John Murray, who ascribes it to an
electric change in the air. ' Last summer,' he says,
we investigated the phenomenon with great care:
the weather had been parched and sultry for some
weeks previous, and the honey-dew prevailed to such
an extent, that the leaves of the currant, raspberry,
&c, in the gardens, literally distilled from their tips
a clear limpid honey -dew, excreted from the plant;
for the phenomenon was observable on those plants
that were entirely free from aphides, and so copious
was it, where these insects were found, that had
their numbers been centuple they could not cer-
tainly have been the source of the supply. The
question with me, however, was set at rest by ap-
plying a lens, having previously washed and dried
* Botan. Arrangement, ii, 440, 3d ed.
t Encycl. of Agriculture, p. 865, s. 5444.
t Introduction to Botany, p. 189,
See Linn. Trans, vol. vi, and Willdenow, Princ. of Bota-
ny, p. 343.
VOL. vi. 2*
18 INSECT TRANSFORMATIONS.
the leaf by a sponge, for in this case the immediately
excreted globules became apparent. 3 *
In all observations upon insects, and the other
minute parts of creation, it is often exceedingly dif-
ficult to distinguish between a cause and an effect.
The question of the formation of honey-dew appears
to us particularly liable to erroneous conclusions; and
we therefore venture to mention a few circumstances
which seem irreconcilable with Mr Murray's inge-
nious theory. The hop fly (Jlphis humuli\ we think,
neither does, nor (for want of appropriate organs)
can, feed on the honey-dew; and if -it did, this feed-
ing would prove rather beneficial than otherwise to
the plant, by clearing it from the leaves whose respi-
ratory functions it obstructs. So far from feeding on
diseased plants, an aphis only selects the youngest
and most healthy shoots, into the tender juicy parts of
which it thrusts its beak (haustellutn) , which in some
species is much longer than the body, and no more
fitted for lapping honey-dew than the bill of JEsop's
crane was for eating out of a shallow plate. Jn the
experiment, tried by Mr Murray, of wiping a leaf,
might not the leaf have been previously wounded,
perhaps, by the beak of some aphis, and hence the
exudation of sap, not honey-dew? and may not the
circumstance of his finding the honey-dew on leaves
where there were no aphides be accounted for on
the principle that the aphides had abandoned, as they
always do, the parts covered with their ejecta, unless
these fell from insects on some over-hanging branch?
It is justly remarked by M. Sauvages, that they
are careful to eject the honey-dew to a distance
from where they may be feeding. "j" We have now
in our study a plant of the Chinese chrysanthemum
(Jinthemis Jlrtemisice folia, WILLD.), the young
* Treatise on Atmospherical Electricity, p. 147, Lond. 1830.
t Trans. Soc. Roy. de Montpellier.
-GENERATION OF INSECTS. 19
shoots of which have swarmed with aphides all the
winter, and the leaves below are covered with honey-
dew. We tried the experiment of wiping it off from
a leaf, but no more was formed when it was protected
by a piece of writing-paper from the aphides above;
while the writing-paper became sprinkled all over
with it in a few hours. By means of a lens, also, we
have actually seen the aphides ejecting the honey -
The almost instantaneous appearance of these des-
tructive insects in great numbers at the same time, is
taken notice of with wonder by almost every writer.
This circumstance, it must be confessed, gives con-
siderable plausibility to the notion of their being
brought by winds, for whence, we may be asked,
-could they otherwise come ? Simply, we reply, from
the eggs deposited the preceding autumn, which, hav-
ing all been laid at the same time, and exposed to the
same degrees of temperature, are of course all simul-
taneously hatched. In the case of the aphides, also,
the fecundity is almost incalculable. Reaumur pro-
ved by experiment, that one aphis may be the pro-
genitor of 5,904,900,0^0 descendants during its life;
and Latreille says, a female during the summer
months usually produces about twenty-five a day.
Reaumur further supposes, that in one year there
imy be twenty generations. We ourselves have
counted more than a thousand aphides on a single leaf
of the hop; and in seasons when they are abundant
when every hop-leaf is peopled with a similar swarm
the number of eggs laid in autumn must be, to use
the words of Good, ' myriads of myriads.' The pres-
ervation and hatching of these eggs in the ensuing
spring must, it is obvious, depend on the weather and
* J. R.
20 INSECT TRANSFORMATIONS.
other accidental circumstances, seldom appreciable by
our most minute observations. *
The history of other insects, erroneously referred to
blighting winds, is more easily traced, from their
being of a larger size than the aphides. The cater-
pillar for example, of L >zotcenia Rosarta, mentioned
before, which rolls the leaf of the rose-tree, is one of
this kind. It is well known as furnishing the common
poetical comparison of ' a worm i' the bud.' Early
in autumn the mother insect deposits an irregularly
oval-patch of yellowish eggs, covered with a cement
Two groups of eggs of the Ro!e-leaf roller (Lozotcsnia Rosa-
na) on a pane of glass.
* J. R.
GENERATION OF INSECTS. 21
of the same colour, sometimes upon the branches of
the rose-tree, but more frequently, as we have ob-
served, upon some smooth object contiguous. For
several successive seasons, we have found more than
one group of these eggs upon the glass panes, as
well as the frame work, of a window, beneath which
a rose-tree has been trained. At present (January
1830) there are two of these groups on one pane,
and three on the frame-work; and as each contains
about fifty eggs, should they all be successfully hatch-
ed, two or three hundred caterpillars would at once be
let loose, and, streaming down simultaneously upon the
rose-tree beneath, would soon devour the greater
number of its buds. As the window faces the east,
the sudden appearance of the insects would make it
appear not unplausible that they had been swept hither
by an easterly wind.
We found, during the same winter, an extraordina-
ry number of similar groups of the eggs of a leaf-
roller (Lozolcenia Ribeana?) on the branches of the
gooseberry and red-currant, in a garden at Lee.
On some small trees, from two to ten groups of eggs
were discovered; and as each group consisted of
from thirty to fifty, a caterpillar might have been
hatched for every bud. After the severity of the
season was over, we had the piece of bark cut off
on which these eggs were attached; and though they
had been exposed on the bare branches to the intense
frosts of 1 829-30, they were hatched in a few days
after being brought into our study. As the currant-
trees were not then come into leaf, we had no food to
supply them with, and they refused the leaves of all
other plants which we offered to them. Had they
been permitted to remain on the trees till they were
hatched, they would probably have not left a single
leaf undevoured. For this spring, at least, these
currant bushes will be safe from their attacks, and of
22 INSECT TRANSFORMATIONS.
course will set at defiance the supposed blighting
winds, which no doubt will, as usual, be accused of
peopling the adjacent gardens with caterpillars. It
may be well to remark, that these caterpillars, when
hatched, are scarcely so thick as a thread of sewing
silk, and being of a greenish colour, they are not read-
ily found on the leaves, the opening buds of which they
gnaw to the very core.*
It does not seem to have ever occurred to those
who thus speak of insectiferous winds, that they get
rid of no difficulty by the supposition; for where, we
may ask, is the east or any other wind to take up
the insects or eggs which it is said to drift along?
The equally sudden disappearance of insects all at
once, which is also popularly attributed to winds, arises
from their having arrived at maturity, and fulfilled the
designs of Providence, by depositing their eggs for
the ensuing season, when they all die, some in a few
hours, though others survive for several days, but
rarelv for weeks.
The sudden and simultaneous appearance of great
numbers of frogs, snails, and other land animals, has
given rise to the extravagant opinion that they have
fallen in a shower frcm the clouds; and some goodly
theories have been devised to account for the pro-
bable ascent of frog-spawn, and the eggs of snails,
into the atmosphere by whirlwinds. The impossi-
bility of this, in consequence of their specific gravity,
is of course left out of consideration by the theorists.
Our distinguished naturalist, Ray, when riding one
afternoon in Berkshire, was much surprised at seeing
an immense multitude of frogs crossing his path, and
on looking into the adjacent fields he found that two
or three acres of ground were nearly covered with
them. They were all proceeding in the same direc-
tion towards some woods and ditches; and he traced
* J<R,
GENERATION OF INSECTS, 23
them back to the side of a very large pond, which, in
spawning time, he was informed, swarmed with count-
less numbers of frogs. He naturally concluded, there-
fore, that, instead of having been precipitated from the
clouds, they had been bred in the pond, from which
they had been invited a short time before, by a re-
freshing shower, to go in quest of food. * Their great
numbers will appear less marvellous, when we consid-
er that a single frog spawns, as De Montbeillard in-
forms us, about 1300 eggs.| Were it not, indeed,
for their numerous enemies, and their not being fit to
propagate till they are three years old, the country
would soon be overrun with these reptiles. We have
more than once seen a similar legion of hair-worms
( Gordii aqualici, LINN.) in a garden at Lee, in Kent,,
every plant and spot of ground literally swarming with
them. Their numbers, however, were easily account-
ed for, as a stream at the bottom of the garden
abounds with them, and, like frogs, they appear to be
amphibious J
The errors of theory, as well as the mistakes of
observers, swayed (unconsciously perhaps) by the
influence of their theoretical opinions, may all be
traced, we think, to the propensity of human nature
to discover resemblances in things, which are after-
wards magnified into close affinity, or even into
identity. We are indebted to one of our best living
entomologists, Mr W. Mac Leay, for clearly point-
ing out the broad distinction between analogy and
affinity.^ The supposed floating of the eggs of insects
in the air thus appears to have originated in drawing
an analogy from the seeds of plants; though, from
the facts we have stated, so far from there being any
* Ray's Wisdom of God in the Creation, p. 156.
t Diet. Classique d'Hist. Nat, vii, p. 495. t J- &
$ Hora? Entomologies, or Essays on Annulose Animals, 8v(K
London, 1819-21.
24 INSECT TRANSFORMATIONS.
analogy, there is no difference more marked than in
this very point that the eggs of insects are, in most
cases, fixed by a glue at the moment of exclusion,
while the seeds of plants are no less uniformly
diffusable and free. The fertile seeds of plants,
it is true, are heavy enough to sink in water, and
consequently as much unfitted for floating in the
air as the eggs of insects; but the contrivances to
counteract this exemplify some of the most beautiful
provisions of nature. The diffusion of the seeds of
thistles, groundsel, dandelion, &c, by means of feath-
ery down, attracts the notice of the most incurious.
Another contrivance of nature for effecting the same
purpose is not only curious in itself, but bears upon
our present subject as illustrating an affinity which it
may be' supposed to have with the ovipositing of certain
insects.
The seeds of the various species of violets are
contained in a capsule of a single cell, or loculament,
consisting, however, of three valves. To the inner
part of each of these valves a seed is attached, und
it remains so for some time after the valves, in the
process of ripening, have separated and stood open.
The influence of the sun's heat causes the sides of
each valve to shrink and collapse; and in this state
the edges press firmly upon the seed; which, it may
be remarked, is not only extremely smooth, polished,
and shining, but regularly egg-shaped. Thus, when
the collapsing edge of the valve slides gradually
and forcibly down over the sloping part of the seed,
it is thrown with a jerk to a considerable distance
There is another part of the contrivance of nature for
the same purpose, in the violacese, worthy of remark.
Before the seed is ripe, the capsule hangs in a droop-
ing position, with the persisting calyx spread over it
like an umbrella, to guard it from the rain and dews,
which would retard the process of ripening: but no
DISPERSION OF SEEDS. 25
sooner is the ripening completed, than the capsule
becomes almost upright, with the calyx for a support.
This position appears to be intended by nature to give
more effect to the valvular mechanism for scattering
the seeds, as the capsule thus gains a higher eleva-
tion (in some cases more than an inch) from which
to project them. Some ripe capsules of a fine variety
of heart's-ease ( Viola tricolor}, which I placed in a
shallow pasteboard box, in a drawer, were found to
have projected their seeds to the distance of two feet.
From the elevation of a capsule, therefore, at the top
of a tall plant, these seeds might be projected twice
or thrice that distance.*
We may mention, as another very curious illustra-
tion of the power in plants of discharging their seeds,
the remarkable instance of a minute fungus ( Sphcero-
bolus stellatusy TODE). This plant has the property
of ejecting its seeds with great force and rapidity,
and with a loud cracking noise ; and yet it is no big-
ger than a pin's head.f
The circumstance alluded to as analogous in in-
sects to this admirable contrivance, occurs in the
forcible discharge of the eggs of some species to a
distance. The ghost moth (Hepialus humuli), for
example, ejects its minute black eggs with so much
rapidity, that De Geer describes them as running
from the oviduct; and they are sometimes for-
cibly thrown out like pellets from a pop-gun. J
c A friend of mine,' says Kirby, ' who had observed
with attention the proceedings of a common crane-
fly (Tipula\ assured me, that several females which
he caught projected their eggs to the distance of
more than ten inches. ' Another instance is men-
* J. R. in Mag. of Nat. Hist., i. 380.
t For a minute account of this singular plant, see Grevill's
Scottish Cryptogamic Flora, No. xxxii.
t De Geer, Mem. des Insects, iv, 494.
Kirby arid Spence, Intr. iii, 66.
TOL. VI. 3
26 INSECT TRANSFORMATIONS.
tioned by the Abbe Preaux, of a four-winged fly,
called by him, Mouche baliste, which, when caught,
jets out its eggs at intervals, as if by the jerk of a
spring.*
The apparent analogy, however, between these in-
A, Plants of Sphcerobofus, natural size. B, magnified view.
C, sectional view, with the seed just previous to projection. D r
the seed in the act of projection. E, a plant immediately after
projection ; a, the seed ; 6 6, a line indicating its course.
* Diet. Classique d'Hist. Nat., Art. MOUCHES BALISTES.
The words are * Insecte a quatre ailes, qui lance ses oeufs a di-
verses reprises, et comme par un ressort, lorsqu'on le saisit.'
DISPERSION OF SEEDS. 27
sects and the plants which discharge their seeds,
will disappear, when we consider that the scattering
of the seeds is, in the plants, a regular and con-
stant process of nature; whereas the insects only jet
out their eggs from fear when caught. The power
of throwing their eggs to a distance, indeed, could
be of no possible use to insects, because they pos-
sess the more efficient power of locomotion.
The facts which we have thus stated with regard
to the seeds of plants being diffused by the means
of winged down, or by the more remarkable capacity
of being projected, differ, as we have shown, in some
important circumstances from the nearly similar ar-
rangement of nature in the economy of insects.
They constitute affinities, but not analogies. On the
other hand, the more universal law of the conti-
nuance of insect life by every new generation being
hatched from eggs, may be illustrated by an analogy,
which is observed even in the most minute instances,
in the generation of plants from seeds.
The diffusion of the seeds of an extensive order
of plants (CryptogamicB) LINN., Jlcotyledones , Juss.,
CellulareSj DE CANDOLLE) being so universal, and
the seeds (sporules) themselves being so minute as
to elude common observation, the phenomena thence
arising have, like the sudden appearance of newly
hatched insects, given some colour to the doctrine of
spontaneous generation. We may see this exem-
plified every day on brick walls recently built, even if
they be covered with a smooth coat of cement. The
first indication of vegetable life on such a wall, par-
ticularly in parts exposed to the trickling down of
rain water, is that of a green silky-looking substance,
having somewhat the appearance of a coat of green
paint. Mr Drummond, of the Cork Botanic Garden,
by accurately watching the progress of this green
matter, which had been unsuccessfully investigated
28 INSECT TRANSFORMATIONS.
by Priestley, Ingenhouz, and Ellis, and had been
mistaken by Linnaeus for a crop of byssi, ascertain-
ed beyond question that it always consisted of the
minute buds of common mosses, such as the wall
screw rnoss ( Tortula muralis) and the common hair-
hood moss (Polytrichum commune) * At Glasgow,
we have repeatedly remarked, that on the walls of
houses, built with freestone raised from a quarry more
than a hundred feet under the surface of the soil,
the whole exterior would, in the course of one month,
appear as green as if painted, with these innumera-
ble germinating mosses. "f
The germination of mosses on walls appears to
arise from the seeds (sporules) being carried into the
air. This process is facilitated by their extreme
minuteness and their comparative lightness, for they
do not sink in water like the seeds of phenogamous
plants and the eggs of insects, as appears from their
germinating on the surface of stagnant water as fre-
quently as on walls. In low situations, the mode in
which the seeds of cryptogamic plants are diffused
is well exemplified in the puff-ball (Lycoperdon),
which, when ripe, explodes its sporules in the form
of a smoke-like cloud. Mosses again, which grow
on trees and walls, if they do not thus explode their
sporules, must drop them into the air; and, as they
chiefly ripen early in spring, the winds which then
prevail will scatter them to considerable distances.
.But we only state this as a highly probable inference
from Drummond's discovery: to detect these all but
invisible seeds floating in the atmosphere, and trace
them in their passage from the parent plant to the wall
or tree where they begin to germinate, we" think is
hardly possible.
If the doctrine be sound, that every plant arises
from seed, we must either believe that innumerable
*Linn. Trans. t J. R.
DISPERSION OF SEEDS. 29
mosses are wafted to the walls through the air, or
adopt the hypothesis that they have existed for cen-
turies in the interior of the rocks of the quarry. That
it is not impossible the seeds may have existed in the
rocks, several curious facts would lead us to believe.
Some seeds, for example, retain the power of germi-
nating for an indefinite length of time; since the
wheat usually wrapt up with Egyptian mummies will
often germinate and grow, as well as if it had been
gathered the preceding harvest. It also bears upon
this subject, that when a piece of ground, which has
never been tilled, is turned up by the spade or the
plough, it immediately becomes covered with a crop
of annuals, not one of which may grow within many
miles of the spot; and a number of them, such as
hedge mustard (Sisymbrium officinale) and chick-
weed (Jllsine media], whose seeds are not winged.
It is no less worthy of remark that all these annuals
will again disappear as soon as the grass is suffered
to spread over the spot which has been dug up. It
is mentioned by Mr James Jennings, in Time's Tele-
scope for 1823, that the coltsfoot ( Tussilago farfara)
is usually the first plant which appears in England in
such cases a circumstance by no means remarkable,
as the seeds of this plant are winged with down, and
extremely light.
A still more minute family of cryptogamio plants,
and consequently more difficult to trace, is well known
by the popular name of mould or mouldiness (Mu-
cedines, LINN.) This, Adolphe Brongniart justly
remarks, is, in one of its groups, nearly allied to the
puff-balls (Ly coper da) , whose mode of diffusing their
seeds we have just described. When mould is exa-
mined by the microscope it is seen to resemble these;
and sometimes various fungi are, when mature, filled
with a blackish dust, supposed to be the seed. Mi-
cheli, of Florence, an eminent botanist, resolved to
VOL. vi. 3*
30
INSECT TRANSFORMATIONS.
try whether this supposed seed would grow if sown on
vegetable substances, and found that it did so. On
his experiments being repeated at Bologna, however,
it was discovered that the mould grew equally well
where none of the black powder bad been sown; but
Spallanzani, by more accurate attention, confirmed the
conclusion of Micheli. He collected a great quan
tity of the dust, and, taking a number of pieces of
moistened bread, apples, pears, gourds, &c, sowed
some thickly, others sparingly, and others not at all.
The result was, that on the unsown substances the
mould did appear, but several days later, and then
greatly less in quantity, than on the sown substances;
while of these two, the pieces thickly sown had more
than double the quantity of the pieces thinly sown,
though, when it came up thick, it did not grow so
tall.
Microscopic views of apple and pear mould. A A, Part of a shrivelled
apple, covered with mould on the inside, a a a , several of the indivi-
dual mould plants highly magnified. 6, a branched one. c t/, seed-ves-
sels, one bursting and scattering its seed, e, one mushroom-shaped. /*, a
portion of. pear mould, of a branched form.
We were much struck last autumn (1829), upon
cutting an apple asunder, to find in the seed-cells a
DISPERSION OF SEEDS. 31
copious growth of the mould with the slender stems
and globular heads figured by Spallanzani. Mould
upon an apple is not indeed wonderful; but the one
in question was not only large, but apparently sound
throughout. Whence, then, came the seeds of this
mould in the very core of the apple ? We have also
met with mould of a different species, resembling the
green mould on the rind of oranges (Jlcrosporium fas-
ciculatum, GREVILLE), even on the kernels of nuts,
when there was no opening save the minute pores in
the shell. Through these pores, then, after being
stripped of the husk that covered them, the seed of
this nut-mould must have entered. This, however,
will not account for the mould in the apple ; the seed
of which, we think, must have been introduced while
it was in embryo, in some such way as the seeds of
the subcortical fungi so abundant on dead leaves
and branches of trees. This again may be illustrated
by the curious facts respecting substances found in the
interior wood of trees. Sir John Clark, for example,
tells us that the horns of a large deer were discovered
in the heart of an oak in Whinfield Park, Cumber-
land, fixed in the timber with large iron cramps, with
which, of course, it had at first been fastened on the
outside.* The eminent naturalist, Adanson, on visit-
ing Cape Verd, was struck with the venerable aspect
of a tree fifty feet in circumference; and recollecting
having read in some old voyages that an inscription
had been made upon such a tree, he was induced to
search for this by cutting into the wood, and, marvel-
lous to say, he actually found it under 300 layers of
wood!* De Candolle, one of the greatest living bota-
nists, remarked ' a frost-bitten part in the wood of a
tree, cut down in 1800, in the forest of Fontainebleau.
This being covered with 9 1 layers of wood, indicated
* Phil. Trans., vol. xli, p. 448. -
t Adanson, Voyages a Senegal.
32 INSECT TRANSFORMATIONS.
that the accident occurred in 1709, so remarkable for
a severe frost. '* With these facts before us, we think
the introduction of the seed of the mould into the cen-
tre of the apple by no means so unaccountable as at
first view it appeared. Be this as it may, we tried,
with the seed gathered from this apple-mould, similar
experiments to those of Spallanzani, with results pre-
cisely similar to his; and being in this way able at
pleasure to produce mould of the same species by
sowing, we are entitled to conclude that all mould
arises from seed, otherwise nature must produce the
same effect from dissimilar causes, which is contrary
to the first principles of sound philosophy. |
* Conv. on Veg. Physiol., i, 59. t J. &
CHAPTER II.
Physiology of Insects' Eggs. Their Colour, Structure, Shape, Size,
and Number.
IT was a notion of Darwin's, (much more ingenious
and plausible than his metamorphoses of shell-fish into
birds,) that the variety in the colours of eggs, as well
as the colours of many animals, is adapted to the pur-
poses of concealment from their natural enemies.
Thus, he says, the snake, the wild cat, and the leopard,
are so coloured as to resemble dark leaves and their
lighter interstices; birds resemble the colour of the
brown ground or the green hedges which they frequent;
"While moths and butterflies are coloured like the flowers
which they rob of their honey. * By following up
this curious theory, Gloger, a German naturalist ,f has
remarked, that those birds whose eggs are of a bright
or conspicuous colour instinctively conceal their nests
in the hollows of trees, never quit them except during
the night, or sit immediately after they have laid one
or two eggs. On the other hand, in the case of birds
who build an . exposed nest, the colours of the eggs
are less attractive. Amongst birds whose eggs are
perfectly white the most conspicuous of all colours,
he instances the kingfisher (Jttcedo\ which builds
in a hole in a river's bank; the woodpecker (Picus),
which builds in the hole of a tree; and the swallow
* Zoonomia, Sect. 39, p. 248, 3d ed., and Botan. Garden,
note on Rubia.
t Verhand. der Gesellsch. Naturforsch. Freunde. Berlin,
1824.
34 INSECT TRANSFORMATIONS.
(Hirundo domeslica)^ whose nest has a very small
opening: while owls and hawks, which scarcely quit
their nests in the day, and pigeons, which only lay one
or two eggs and sit immediately after, have also white
eggs. The bright-blue, or bright-green egg, again,
belongs to birds which build in holes, as the starling
(Sturnus vulgaris), or which construct their nests of
green moss, or place them in the midst of grass, but
always well covered. Almost all singing birds, he al-
leges, lay eggs of a dull or dark ground, and various-
ly speckled; and they for the most part build open
nests with materials similar in colour to the eggs, so
that no evident contrast is presented which might lead
to their discovery and destruction. We may add from
.Darwin the examples of the hedge-sparrow (Accentor
modularis), whose eggs are greenish blue, as are
those of magpies and crows, which are seen from be-
neath in wicker nests, between the eye and the blue
of the firmament.*
As this theory is but indirectly connected with ouf
subject, we cannot here spare room to examine it ;
but we may remark, that it appears to us much more
beautiful and ingenious than true: for we could enu-
merate more instances in which the principle fails
than holds good. Gloger's instances also are far
from accurate; for though the king-fisher, for example,
hides her shining white eggs in a hole, yet that will
not conceal them from the piercing eyes of their chief
enemy, the water rat, which, like all burrowing ani-
mals, can see with the least possible light. Many
birds, also, which lay bright-coloured eggs, make
open nests; the thrush, .for example, whose clear-blue
eggs, with a few black blotches, are far from being
concealed by the plastering of clay and cow-dung
upon which they are deposited. The green finch
* See also St Pierre; Studies of Nature, ii, 393 ; Note.
COLOURS OF EGGS. 35
(Fringi'la chloris, TEMMINCK), again, which builds
an open nest of green moss, lined with horsehair,
black or white as it can be had, lays clear white eggs
with red spots, precisely like those of the common
wren and the willow wren (Sylvia Trochilus), which
build covered nests with a small side-entrance; while
the house-sparrow (Fringilla domestica) lays eggs of
a dull, dirty green, streaked with dull black, and al-
ways builds in holes or under cover. These objec-
tions will render it unnecessary for us to follow Darwin
into his fanciful account of the origin of the colour of
eggs, which he ascribes to the colour of the objects
amongst which the mother bird chiefly lives acting
upon the shell through the medium of the nerves of
the eye ; for, if this were correct, we should have the
green-finch and the red-breast, instead of their white
eggs, laying blue ones like the hedge-sparrow and the
firetail.
Upon a partial view of the subject, we might bring
many facts to support the theory from the colour of
the eggs of insects. The nettle butterflies, for ex-
ample, the small tortoise shell (Vanessa Urticce), the
peacock (V. Jo), and the admirable (V. Atalanla) ,
all lay eggs of a green colour, precisely similar in
tint to the plant to which they are attached. On the
contrary, the eggs of the miller moth (Jlpatela Lepo-
Tina, STEPH.), which are deposited on the gray bark
of the willow, are light purple; another beautiful geo-
metric moth (Geometra illunaria), which Sepp* calls
Hercules je, lays its pink eggs in the fissures of the
bark of the elm ; the puss moth ( Cerrura vinula)
lays shining brown eggs on the green leaf of the pop-
lar; and the garden white butterfly (Pontia Brassicce)
lays a group of yellow ones on a green cabbage or cole-
wort leaf, but not of so bright a yellow as those of the
seven-spot ladybird (Coccinella Septempunctata),
* Sepp, der Wonderen Gods, Tab. 35.
36 INSECT TRANSFORMATIONS.
patches of which may be found on many sorts of
leaves during the summer months.
The immediate origin of colour in the eggs of in-
sects is in some cases the enclosed yolk shining through
the transparent shell; but in others, the shell is not
uniformly transparent, but ringed, banded, or dotted
with opacities of various colours. In the eggs of the
drinker moth (Odonestis potaioria), for example, there
are two circular rings of a green colour, from the
green yolk appearing through the shell; while the
rest of the shell is white and opaque, as we have prov-
ed by dissection.* Certain ruddy spots on the white
eggs of the small rhinoceros beetle ( Oryctes nasicornis,
ILLIGER) were discovered by Swammerdam to be the
red mandibles and spiracles of the unhatched grub
seen through the shell; and the white ground, we in-
fer, was similarly caused by the body of the grub.|
This, however, cannot be the origin of the bright red
spots on the beautiful yellow egg of the brimstone
moth (Rumia cratcegata^ DUPONCHEL), which may,
perhaps, have a similar origin to those of birds.
With respect H;o the eggs of birds, it has been re-
marked by Mr Knapp,J that in those ' of one hue,
the colouring matter resides in the calcareous part ;
but where there are markings, these are rather ex-
traneous to it than mixed with it. The elegant blue
that distinguishes the eggs of the fire-tail ( Sylvia
ph&nicurus, LATH.), and of the hedge-sparrow,
though corroded away, is not destroyed by muriatic
acid. The blue calcareous coating of the thrush's
egg is consumed; but the dark spots, like the
markings on the eggs of the yellow-hammer, house-
sparrow, magpie, &,c, still preserve their stations on
* J. R.
t Swammerdam, Book of Nature, i, J.3.
t Journal of a Naturalist, p. 230.
SHELLS OF EGGS. 37
the^ film, though loosened and rendered mucilaginous
by this rough process. Though this calcareous mat-
ter is partly taken up during incubation, the mark-
ings upon these eggs remain little injured even to the
last, and are almost as strongly defined as when the
eggs are first laid. These circumstances seem to im-
ply, that the colouring matter on the shells of eggs
does not contribute to the various hues of the plum-
age; but, it is reasonable to conclude, are designed to
answer some particular object not obvious to us : for
though the marks are so variable, yet the shadings
and spottings of one species never wander so as to
become exactly figured like those of another family,
but preserve year after year a certain characteristic
figuring. 7
Most of these remarks will apply to the colours of
the eggs of insects: but though we can in most in-
stances trace no connexion between the colours of
eggs and the perfect insect, there is a striking ex-
ception in the egg of the brimstone moth mentioned
above, which corresponds exactly in colour with the
wings of the moth, though the caterpillar is of a dull
brown.
The eggs of insects, like those of birds, have a
shell enclosing the germ of the caterpillar with a
peculiar matter for its nourishment, like the white
and yolk of a bird's egg, provided for the nourishr-
ment of the contained chick. These several parts,
however, are very different in substance from the
eggs of birds. The shell of the bird's egg is brittle,
opake, chiefly composed of chalk (carbonate of
/inie), and lined with a very thin tough membrane;
while in the egg of an insect the shell is not brittle,,
is transparent, contains no lime (for it is not per-
ceptibly acted upon by diluted sulphuric acid), and
no lining membrane can be detected. It appears,
indeed, very similar to the transparent portion of a
VOL. vi. 4
38 INSECT TRANSFORMATIONS.
goose-quill in the eggs of the drinker and ether moths
which we have dissected;* but in the eggs which are
deposited in moist places, and in those of spiders, it is
extremely thin.t The eggs of saw-flies, ants, &c,
which grow larger, as we shall afterwards show, du-
ring the process of hatching, must possess an expansi-
ble shell to allow of their enlargement. The yolk and
white in the eggs of birds are separated from each
other by a very fine membranous bag in which each
is contained ; but in the eggs of insects, what an-
swers to the yolk consists of distinct minute globules,
which float in the white, if we may call it so, for it does
not, as we have ascertained, coagulate in boiling water.
The eggs of the gypsey moth (Hypogymna dispar),
which we boiled, still continued partly fluid, though
the brown matter answering to the yolk was consider-
ably thickened. The portion which does not thicken
by boiling most probably forms the first internal fluids
of the caterpillar, answering to the blood of quadru-
peds. The point where the caterpillar originates,
answering to the scar ( Cicatricula) in the eggs of
birds, we can readily distinguish even by the naked
eye in the larger species of eggs, as it lies always
immediately under the shell.* ' Having directed,'
says the younger Huber, ' my close attention to the
eggs of ants, I remarked that they were of different
sizes, shades, and forms. The smallest were white,
opaque, and cylindrical ; the largest, transparent,
and slightly arched at both ends ; while those of
a middle size were semi-transparent. On holding
them up to the light I observed a sort of white ob-
long cloud; in some, a transparent point might be
remarked at the superior extremity ; in others, a
clear zone above and underneath the little cloud. The
largest presented a single opaque and whitish point
* J. R. t Kirby and Spence, Intr. 86.
GERM OF EGGS. 39
in their interior. There were some whose whole bo-
dy was so remarkably clear as to allow of my very dis-
tinctly observing the rings. On fixing attention more
closely upon the latter, 1 observed the egg open, and
the larva appear in its place. Having compared these
eggs with those just laid, I constantly found the latter
of a milky whiteness, completely opaque, and smaller
by one-half, so that I had no reason to doubt of the
eggs of ants receiving a very considerable increase in
size; that in elongating they become transparent, but
do not at this time disclose the form of the grub, which
is always arched.'*
The germ in the egg of the garden spider (Epeira
diadema) is described by the accurate Heroldt, as
appearing to the eye in form of a minute white point
immediately under th*e shell, and in the centre of the
circumference. On examining this point more nar-
rowly, it is found to be of a lenticular shape, and
composed of innumerable whitish granulations of a
globular form, differing only from the globules of the
yolk in being smaller and more opaque, as may be
seen by squeezing out the contents of a spider's egg
into a watch-glass. The most singular circumstance
observed by Heroldt was, that in some species of spi-
ders an egg appeared to have a considerable number
dispersed upon different points of the surface; but all
these ultimately united into a single germ.!
The eggs of the glow-worm (Lampyris noctiluca),
as we ascertained from those deposited by one which
we found in 1829, at Rudesheim, on the Rhine, are
golden yellow, somewhat resembling cherry-tree gum,
while the internal substance is similar in consistence
* M, P. Huber on Ants, p. 68.
1 Heroldt, Exercit. de Generat. Aranearum in Ovo, and his
Unters. iiber die Bildung der Wizbellosen Thiere im Eie.
40 INSECT TRANSFORMATIONS.
to the wax of the ears, and in form of granules which
are even externally apparent.*
We are accustomed to consider the form of eggs so
nearly regular, that the epithet c egg-shaped' is fre-
quently applied to other things, and is well understood;
but the eggs of insects, though most commonly round,
are seldom, like those of birds, smaller at one end
than at the other, while they often exhibit forms never
seen in the eggs of birds, such as cylindric, flat,
depressed, compressed, prismatic, angular, square,
boat-shaped^ &c. These varieties of form are just-
ly referred by Kirby and Spence to the c manifold wis-
dom' (7roAo7ro<x/Ao; ffo0**)J ofthe Creator; but we have
some hesitation in admitting their limitation of this to
his ' will to vary forms, and so to glorify his wisdom,
and power independently of other considerations,'^
and think it would be more truly philosophic to con-
fess our ignorance where we cannot explain what is
above our comprehension. Paley, indeed, says, such
facts c might induce us to believe that variety itself,
distinct from every other consideration, was a motive
in the mind of the Creator, or with the agents of his
will;' but he immediately adds, ' to this great variety
in organized life the Deity has given, or perhaps there
arises out of it, a corresponding variety of animal ap-
petites, and did all animals covet the same element,
retreat, or food, it is evident how much fewer could be
supplied and accommodated, than what at present live
conveniently together, and find a plentiful subsistence. '||
The latter remark, we think, completely destroys the
former, and it will lead us to what appears to be
* J. R.
t Dumeril, Consider. G^ru rales, p. 49; and Insect Archi-
tecture, p. 19.
t Ephes. iii, 10. Introd. iii, p. 95.
H Natural Theology, p. 345, 14th ed.
FORMS OF EGGS.
41
the true cause of the varied forms of the eggs of in-
sects.
Eggs of a butterfly and of a moth, magnified.
The cause of the eggs of birds being nearly the
same in shape, arises, we should say, from the similar
forms of the animals themselves; while insects being
much more varied in shape, require corresponding
varieties in the forms of their eggs. The ostrich,
the eagle, and the wren, for example, differ much
more in size than in their general form; but the
earwig, the garden-spider, butterflies, beetles, and
grasshoppers, differ much more in form than in size,
and consequently require eggs of varying forms to
contain their progeny. We confess, however, that
we cannot always trace the mathematical causes of
these diversities of form in the eggs of insects; for
though there prevails a general resemblance in those
families and groups the most nearly allied, yet in
others, even the species of the same genus exhibit
differences which cannot be thus accounted for. In
two species of Vanessa, for instance, the small and
the great tortoise-shell butterflies, which differ in
little but size, the egg of the small is cylindric with
eight prominent ribs, while that of the great is shap-
ed like a Florence flask, and quite smooth and uni-
form.*
The ribbing of the eggs of the small tortoise-shell
* Sepp, der Wonderen Gods, Tab. ii, and viii.
VOL. vi. 4*
42 INSECT TRANSFORMATIONS.
butterfly (Vanessa uiirc(R\ which is also found on
those of most of the species, leads us to remark that
insect eggs are frequently sculptured in a very beau-
tiful manner, far out-rivalling in elegance of design
and delicacy of workmanship the engravings which
we sometimes see on eggs brought from India and
China. Some of them, when seen through a micro-
scope, remind us of the fine crustaceous shells called
sea-eggs, a resemblance which is well exemplified
in the egg of the angle-shades moth (Phlogopfiora
meticulosa, STEPHENS), as compared with the Cly~
peaster of Parkinson.
a, magniiieu egg of tlie angle shades inutli ( P/il<,ir<, ,nura mcti-
cnlosa) ; 6, sca-egjr (Clypcastcr,) natural size.
These channellings appear to correspond in most
cases with the rings of the caterpillar to be hatched
from the egg; but the design of the other sculptures
on these eggs has not yet been discovered by the
investigations of naturalists, and may. probably, for
ever elude human penetration. But though we
cannot tell why an insect's egg is so tastefully carved,
we can admire the minute delicacy and extraordinary
regularity of the markings. The egg of the meadow
brown butterfly (Hipparchia Jurlina) is crowned at
the upper end with sculptured work in the form of
tiles or slates, as if to defend it from injury, while
others are covered with a sort of net-work of extreme-
ly minute six-sided meshes.
FORMS OF EGGS. 43
r,, the egg ui the meadow brown-butterfly, magnified; />, egg
of the biimstone-moth (Rumia Crata-gata), magnified.
The design of the appendages to some sort of
eggs is much more apparent, and affords us some
admirable illustrations of prospective contrivance.
The eggs of the ephemerae, for example, are smooth
and oblong, resembling caraway comfits, a form
which Swammerdam proved to be admirably adapted
for diffusing them through the water, where, he says,
they are dropt by the mother insect. For this pur-
pose he placed ' a few of them on the point of a
knife, and letting them fall gently into water, they
immediately separated of themselves in a very curious
manner.'* The same accurate observer describes a
very remarkable appendage in the egg of the water,
scorpion (Nepa cinerea, LINN.), an insect by no
means rare in Britain. This egg is furnished with
a coronet of seven bristles disposed like the down
on the seed of the blessed thistle, ( Centaurea
benedicta, WILLDENOW); and before they are de-
posited these bristles closely embrace the egg next
to them in the ovary like a sort of sheath, as if a
chain of thistle-seeds were formed, by placing each
successively in the bosom of the down of the one
next to it. As the mother insect deposits these eggs
in the stems of aquatic plants, the bristles, which are
partly left on the outside, are probably intended to
* Svvamm. Book of Nature, i, 104,
44 INSECT TRANSFORMATIONS.
prevent the aperture from being closed up by the ra
pid growth of the plant.
Reaumur gives an interesting description of a
similar egg deposited by a common dung-fly, of a
yellowish-orange colour, (Scatophaga stercoraria,
MEIGEN). These eggs are furnished at the upper
end with two divergent pegs, which prevent them
from sinking into the dung where they are placed by
the parent, while they are permitted to enter suffi-
ciently far to preserve them moist. Both circum-
stances are indispensable to their hatching; for
when Reaumur took them out of the dung, they
shrivelled up in a few hours, and when he immersed
them farther than the two pegs, they were suffocated,
and could not afterwards be hatched.*
, Dnng-fly Scatophaga Stercoraria) ; 6 r, front and side views
of its eggs- magnified ; d d d, a number of these eggs deposited in
cow dung.
Before we began to study the habits of insects, we
found upon a lilac-twig, in the neighbourhood of
London, a singular production, which we took for a
very delicate fungus, and supposing it not to be
common, we carefully preserved the specimens; but
we have since learned, with no little surprise, that
these are the eggs of the lace-winged fly, (Chrysopa
reticulata, LEACH.) Reaumur says that several
naturalists have described them as fungi, which is
not to be wondered at; for they consist of a small
oval greenish-white head, similar to the apple-mould,
* Rraumur, iv, 379.
POSITION OF EGGS. 45
with a white transparent stem, more than an inch
high, not thicker than a human hair, but much more
stiff and rigid. About a dozen of these eggs are
deposited in a single and sometimes in a double line,
upon the leaves and branches of elder or other trees
and plants abounding with aphides, upon which the
grubs feed when hatched. The footstalks of these
eggs are formed by the mother-fly attaching a drop
of gluten to the branch, and drawing it out (as a spi-
der does its line) to the requisite length before the egg
is deposited on its summit. As she uses her body for
a measure, the footstalks are by consequence, all near-
ly of equal length. It is evidently the design of these
footstalks to place the eggs out of the reach of the
grubs of lady-birds (Coccinellce) arid of aphidivorous
flies (Syrphi), which frequent the same situations and
Twig of lilac, bearing the eggs of the lace winged fly (Ckrypscpa
rtticulataj Leach). The fly is seen resting on the lowest leaf.
46 INSECT TRANSFORMATIONS.
might devour them. The footstalks are so smooth
and slender that these grubs could not climb them, as
we have proved by experiment.*
The ichneumon fly (Ophion luteum), whose larvae
feed upon the caterpillar of the puss-moth, also de-
posits eggs with a footstalk; and what is most singu-
lar, these larvaB, after they are hatched, during the
first stage of their existence, continue attached to the
shells of their eggs. It is not till the puss has form-
ed her cocoon that they devour her, and spin their
own cocoons under its cover, j*
The eggs of insects do not seem to hold any regu-
lar proportion, so far as regards size, with their parent
insects; for some large moths lay very small eggs,
while others of a small size lay eggs considerably lar-
ger. Kirby and Spence think it probable that eggs'
which produce females are generally larger than male
eggs; with the exception of the hive-bee, in which
the reverse takes place. Huber, as we have seen
above, found the eggs of ants of different sizes, from
which he was led to discover that they increase in size
after being deposited.
It has been remarked, that animals of prey are less
prolific than those which live on vegetable food; and
a similar principle appears to hold to a certain extent
amongst insects, the most prolific families belonging,
with few exceptions, to those which devour vegeta-
ble or animal substances beginning to decay and
putrefy.
Thus it is that the eagle lays only two eggs, while
the wren lays eight, and the pheasant twenty-four ;
and in the same way the dragon-flies (Libellulina,
MAC LEAY), do not lay above two dozen eggs, the
lace- winged flies (Hemerobidce) still fewer, and the
noontide fly (Mesembrina meridiana, ME i GEN) only
* J. R. t See Insect Architecture, pp. 195 325, 6.
FECUNDITY OF INSECTS AND FISHES. 47
deposits two eggs; while a single plant-louse (Aphis),
as we mentioned before from Reaumur, may be the
living progenitor of 5,904,900,000 descendants, and
the queen of the warrior white ants ( Termes bellico-
susj SMEATHM.), produces 31,536,000 eggs in one
year.
We may illustrate this subject by an extract exem-
plifying the proportionate fecundity of the animal king-
dom in general. c Compared with the rest of ani-
mated nature,' says Daly ell, c infusion animalcula are
surely the most numerous: next are worms, insects,
or fishes; amphibia and serpents, birds, quadrupeds;
and last is man. The human female produces only
one at a time, that after a considerable interval from
birth, and but few during her whole existence. Many
quadrupeds are subject to similar laws; some are
more fertile, and their fecundity is little, if at all, in-
ferior to that of certain birds, for they will produce
ten or twenty at once. Several birds will breed fre-
quently in a year, and have more than a single egg
at a time. How prodigious is the difference, on de-
scending to fishes, amphibia, reptiles, insects, and
worms! Yet among them the numbers cannot be
more different. According to naturalists, a scorpion
will produce sixty-five young; a common fly will lay
144 eggs; a leech, 150; and a spider, 170. I have
seen a hydrachna produce 600 eggs, and a female
moth 1 100. A tortoise, it is said, will lay 1000 eggs,
and a frog 1 100. A gall insect has laid 5000 eggs;
a shrimp, 6000; and 10,000 have been found in the
ovary, or what is supposed to be that part, of an as-
carides. One naturalist found above 12,000 eggs
in a lobster, and another above 21,000. An insect
very similar to an ant (Mulillal) has produced 80,000
in a single day ; and Leeuwenhoeck seems to compute
four millions in a crab. Many fishes, and those
which in some countries seldom occur, produce in-
48 INSECT TRANSFORMATIONS.
credible numbers of eggs. Above 36,000 have been
counted in a herring; 38,000 in a smelt; 1,000,000
in a sole; 1,130,000 in a roach; 3,000,000 in a spe-
cies of sturgeon; 342,000 in a carp; 383,000 in a
tench; 546,000 in a mackerel; 99:2,000 in a perch;
and 1 ,357,000 in a flounder. But of all fishes hither-
to discovered, the cod seems the most fertile. One
naturalist computes that it produces more than
3,686,000 eggs; another 9,000,000; and a third
9,444,000. Here, then, are eleven fishes, which
probably, in the course of one season, will produce
above thirteen millions of eggs; which is a number so
astonishing and immense, that, without demonstration,
we could never believe it true.'*
The fecundity of insects is no less remarkable than
that of fishes. In some instances, particularly in those
already mentioned, the numbers produced from the
eggs of a single female, far exceed the progeny of any
other class of animals. It is this extraordinary fecun-
dity which, under favourable circumstances, produces
countless swarms of insects that give origin to the
opinion of their being spontaneously generated by
putrefaction, or brought in some mysterious way by
blighting winds. The numerous accidents, however,
to which insects are exposed from the deposition of
the egg till their final transformation, tend to keep their
numbers from becoming excessive, or to reduce them
when they are at any time more than commonly nume-
rous.
* Introd. Observ. to Spallanzani, xiv.
CHAPTER III.
Maternal Care of Insects in depositing their Eggs. Solitary Bees.
Wasps. Ichneumons. Moths. Butterflies. Gnats. Mistakes
of Instinct.
LORD KAIMES, in his ' Gentleman Farmer,' men-
tions the singular fact that the female sheep, weeks
before yeaning, selects some sheltered spot where
she may drop her lamb with the most comfort and
security; and when forcibly prevented from going
there, she manifests the utmost uneasiness. But
this instance of prospectively providing for a future
progeny is exemplified much more strikingly in most
insects, in consequence of the great difference of
their economy compared with that of other animals.
The sheep and other mammalian quadrupeds suckle
their young, and watch over them with the most
affectionate care during the earlier and more help-
less stage of their existence. This, on the contrary,
is only found in a few cases among insects, such as
the social bees, wasps, and ants; for the greater
number of species never live to see their descend-
ants. The numerous families, indeed, of moths,
butterflies, and other winged insects, seldom live
more than a few days after they have deposited
their eggs, though some other species probably live
many months. The latter, however, are only ex-
ceptions to the general rule, that insects, after depo*-
siting their eggs, very soon die. The wisdom of
Providence, therefore, has endowed female insects
with the most wonderful acuteness and skill in anti-
cipating the wants of their young, when they escape
VOL. vi. 5
50 INSECT TRANSFORMATIONS.
from the egg, and have no mother to direct or pro-
vide for them.
We have numerous beautiful instances of this in
the solitary bees and wasps, which perform indefa-
tigable labours in hewing out nests in wood and stone,
and building structures of clay, leaves, cotton, and
other materials, as we have elsewhere detailed at
length.* But we recently met with an example of
this, which we shall briefly notice. A small solitary
bee, (Chelostoma florisomne?) not so large as the
domestic fly, and more slender in the body, instead
of digging into the ground like its congeners,! bores
a hole in a tree about the diameter of a wheat straw,
and, when empty, resembling externally the timber
holes of the furniture beetle (Jlnobium pertinax) for
which, indeed, we at first mistook them, till we were
undeceived by seeing the little bees going in and out.
When the work is completed, however, the hole can
only be detected by a practised eye, for it is neatly
covered with a substance, the nature of which remains
to be discovered. It is a gray semi-transparent
membrane, somewhat resembling the slime of a snail
when dried; but whether it is secreted by the bee
like wax, or gathered from plants like propolis, we
cannot tell. As we had a whole colony of these little
wood-boring bees in the stump of a growing poplar
at Lee, we cut out several of the perforations, in
order to examine the interior. These we found more
than an inch deep, and filled to the brim with a thin
whitish honey; but, like those of the larger carpenter
bees of a different genus (Xylocopa), they were divi-
ded by several partitions of the same membranous ma-
terial.
The circumstance, however, which induces us to
give these details here, relates to the eggs deposited
* See Insect Architecture, pp. 24 64, &c. t Ibid, p. 43.
EGGS OF THE SOLITARY BEE. 51
in these singular perforations. It is obvious, if the
eggs were laid in the midst of the liquid honey, that
they would either be prevented from hatching, or the
grub would be suffocated in the first stage of its exist-
ence. Every chamber of the little nest is so full of
honey, that it is difficult to divine how this is to be
avoided, and it was only after repeated and anxious re-
searches that we found a solution of the difficulty. It
is this: the mother-bee, when she has filled a chamber
with honey, glues a single egg, a hair's breadth or two
above its surface, and at a similar minute distance she
stretches the membranous partition, leaving between
this and the surface of the honey just sufficient space,
and no more, for the newly hatched grub to crawl all
round. On opening one of these perforations after
the grub had been some time hatched, we found it
keeping aloof from the honey, and resting on the
upper margin, from which it seemed to have stretch-
ed its head when feeding to the centre, instead of
eating at the circumference. The honey was also
then become thicker in consistence, and, in conse-
quence of what had been consumed, formed a hollow
cup.*
Reaumur describes the nest of a bee of the
same family (Jlndrena cineraria, FABR.), which is
found in the neighbourhood of London, and differs
from the preceding in making perforations, not in
trees, but in the ground, and lining these with the
membranaceous substance that composes the parti-
tions and the outer covering. He takes no notice,
however, of the prospective ingenuity with which
the egg is placed above the surface of the fluid
honey. |
The various species of nests thus prepared by the
parent insects for depositing their eggs, are not
merely intended for holding provisions and shel-
* J. R. t Reaumur, Mem., vol. vi, p. 131.
52 INSECT TRANSFORMATIONS.
tering the young grub from the inclemencies of the
weather, or from being preyed upon by birds. There
are more insidious and no less destructive enemies
than these to guard against. This we shall imme-
diately show from the economy of other families of
the same order, whose proceedings also strictly
illustrate the subject of maternal care. In popular
works on natural history the insects alluded to are
indiscriminately called Ichneumons, a name signifying
PryerSj and first given by Aristotle to wasps. But
recently this term has been considerably restricted,
and therefore does not properly apply to many
insects whose economy resembles the true ichneu-
mons. It is the practice, then, of a very great num-
ber of insects, of different orders and families, to take
advantage of the labours of other insects in pro-
viding for their progeny, in the same way as the
common cuckoo and the cow-bunting of America
(Emberiza pecoris, WILSON) lay their eggs in the
nests of other birds. The venerable Dr Jenner was
the first to publish,* what had long been known to
our peasants, that the young cuckoo, when hatched,
soon ejects from the nest into which it has been
surreptitiously introduced the eggs or young of its
foster parent; but the insects under notice act still
more ungratefully. They do not, indeed, live upon
the honey or other provision stored up by the
builder of the nest for the use of her own young,
since, being all carnivorous, this is not to their taste;
but they permit the rightful owner of the food to
feast and fatten on it, that they may make of him a
more substantial repast. The great numbers of dif-
ferent species of insects which are reared in this sin-
gular manner would appear almost incredible to one
who had not studied their economy; but it cannot
fail to meet the young entomologist at the very
* Phil. Trans, for 1788, p. 219.
PRECAUTIONS OP INSECTS. 53
outset of his studies; for it is scarcely possible for many
broods of insects to be reared without observing it.
The insidious proceedings of these cuckoo insects,
as we may not inappropriately call them, give rise to
remarkable displays of ingenuity on the part of the
mothers whose progeny is exposed to their felonious
designs. It is the usual practice of the solitary bees
and wasps to leave the whole task of constructing and
provisioning the nest to the female, the male, like an
American Indian, taking no part in those domestic
concerns. In this case, though she is seldom absent
from the spot for more than two or three minutes at a
time, some prying Chrysis or Tachina often glides
into her domicil, and finds time to deposit its egg
and to escape before her return. Other solitary bees
exhibit both more civilization and more cunning; for
the male assists, at least, in watching and guarding
the nest, if he does not lend a hand in its construc-
tion. The proceedings of one of these solitary bees
(Halictus fulvocinctusy STEPH.), indigenous in the
vicinity of London, has frequently fallen under our
observation. It constructs a gallery, having on the
outside only a single perpendicular passage, but bran-
ching out into seven or eight, at the bottom of each
of which is placed a globule of pollen kneaded up with
honey about the size of a pea, where an egg is depos-
ited. Walckeria'er, who observed these insects with
great care, remarks, that they only work during the
night in making their galleries; and our observations
so far agree with his, that though we have observed
some dozens of their nests, we never saw them at
work in the day. Instead of this, either the male or
the female always remains at the entrance of the nest
(which its head exactly fills) ready to give no friendly
reception to any enemy that may venture to intrude.
We have otten seen, indeed, the ruby-tail fly (Chrysis
VOL. vi. 5*
54 INSECT TRANSFORMATIONS.
ignita), on approaching this vigilant sentinel, fly off
in all haste, with evident fear of the consequences.
But, as Walckenaer justly remarks, should the part-
ner of its cares return from a foraging excursion, and
take two or three circular flights around the entrance
to announce its arrival, the sentinel bee immediately
makes way by withdrawing into the interior. Should
the sentinel bee be absent through any cause from
its post, and the forager enter without announcing
its arrival, it is immediately driven back and pu-
nished for so unpardonable a breach of etiquette.*
Another circumstance worthy of notice in the
manners of these bees (Halicti) is, that they fly
directly into the entrance of their nests without ever
alighting upon any contiguous object, a circum-
stance which is attributed by Walckenaer to their
fear of enemies, numbers of which are always lurk-
ing about with evil intent. More than one species
of spider and several sorts of wasps lie in wait to
make prey of them, besides those we have men-
tioned as being on the alert to introduce their eggs
into their nest. But their most formidable enemy is
a solitary wasp (Cerceris ornatci), numbers of
which make their nests in the very midst of their
colonies. The wasps surround the interior margin
of their holes with a rampart of sand, agglutinated
with a whitish mortar, and well polished. The gal-
lery is five inches deep, somewhat in the form of an
S, in which the female lays her eggs, with a store of
provisions for her future young, consisting of the
living bodies of her bee neighbours, the poor Halicti.
It is only on fine days, between eleven and four
o'clock, that the mother wasp engages in the chase
of the bees, and may be seen flying with the most
lively ardour around their nests. When an unfortu-
* Walck. Mem. des Abeilles Solit. Paris, 1817.
INSECTS OF PREY. 55
nate bee ventures at this time to approach its home,
the wasp pounces upon it as a .hawk would pounce
upon a sparrow, seizes it by the back of the neck,
carries it to the ground, and placing it by the side of
a small stone or clod of earth, she turns it round upon
its back. Then standing upon its belly in an attitude
of conscious triumph, she darts her sting into the
lower part of its head, in such a manner as to stupify
it, but not to kill outright. As soon as she has in
this manner laid in a sufficient store of half-dead
bees, she closes up the entrance.*
Several species of this family of wasps (Cerceris
aurita, LATH., and C. quadrifasciata, Bosc) are
of essential service to agriculturists by provisioning
their nests with destructive weevils (Curculionidce),
so injurious to orchards and nurseries.")" Other
families of this order in a similar way provide for
their progeny a supply of living insects of different
species, of which interesting accounts have been
given by more than one naturalist. J
The insects, however, of these marauding tribes
are not permitted to carry on their depredations on
their more peaceful neighbours with impunity; for
nature has provided other races of animals to make
prey of them. We do not allude merely to birds
and reptiles, which devour as many of those carni-
vorous wasps as they can catch ; for there is also a
numerous tribe of insects who have the address to
foil them at their own weapons. All the careful
stratagems of the mason wasp ( Odynerus murarius,
LATR.), in rearing her turretted outworks to defend
her premises while she excavates her galleries,^
often prove ineffectual in guarding against the insi-
* Walck. ; Latreille, Annales du Museum, torn, xiv; and
Bosc, Ann. de 1'Agric, vol. liii.
t Bosc, Ann. de 1'Agric., vol. liii.
See Insect Architecture, pp. 26-33. $ Ibid, pp. 30 - 32.
56 INSECT TRANSFORMATIONS.
dious intrusion of a common ichneumon fly (Pimpla
manifestator, GRAVENHORST), easily known by its
being black, with the legs red. This ichneumon
sometimes pays a visit to the nest of the wasp before it
is completed, for Reaumur has seen one peep into the
entrance and then start back as if afraid of its
depth; but, for the most part, she waits patiently till
the wasp, having laid in a store of caterpillars for
the young one, closes up the doorway with a bar-
ricade of kneaded clay. It is this very barricade
which the ichneumon determines to assail in order to
find a nest ready prepared and stocked with provi-
sions for her own progeny. With this design she
makes use of her ovipositor, which is as admirably
adapted to the purpose of those as the saw-flies or
the tree-hoppers (Cicadce.)
The ovipositor of all the true ichneumons (Ich-
neumonidce) is similarly constructed, consisting of a
borer enclosed in a sheath, which opens ^through its
whole length like the legs of a pair of compasses. It
is longer or shorter, and stronger or more slender,
according to the substances which it may be neces-
sary to penetrate when the eggs are deposited. The
description, therefore, of the ovipositor of the one
just alluded to (P. manifestator) will be sufficient to
give the reader a distinct notion of the others
Being intended to penetrate into the deep holes dug
by mason wasps, the ovipositor of this insect is
nearly three inches long, and, as it is not concealed
in the body like those of gall flies, it appears like a
tail formed of a long black bristle. On examining
this a little more narrowly, we find that what
appears to be a single bristle is in reality three, two
side ones forming a sheath, and the middle one a
borer or brad-awl for piercing the clay barricado of
the mason wasp's nest. The termination of the
borer is not, however, smooth, like that of a brad-
ICHNEUMONS.
57
awl, but toothed like a saw, only the teeth, seven or
eight, are not oblique, but perpendicular, a structure
better fitted for acting upon clay, as the teeth will
not become so readily clogged, and the instrument
will be more easily retracted. The figures will make
this more perspicuous than the best description.
, the Pimpla manifcstator ; 6, its ovipositor opened outwards ;
c c c e, magnified view of its ovipositor ; rf, the toothed point of the
borer.
In order to study the economy of the mason wasps
(Odyneri) more effectually, Reaumur made an arti-
ficial vespiary of sand and mortar upon a wall, which
at the same time gave him an excellent opportunity
of observing the manoeuvres of the ichneumons. * I
perceived,' he tells us, 4 one of these ichneumons,
at the instant it alighted on the spot under which
so many of the little green caterpillars had been
stored up by the wasps. Its long tail, which it
carried horizontally, appeared to form but one bristle,
though it was really composed of three; and though
it carried it on a line with its body, it soon showed
me that it was capable both of raising and lowering
it, as well as of bending it in various directions,
and in different proportions to its length. It moved
its ovipositor so as to bring it into a bent position
under its body, protruding it even beyond its own
head; taking care to direct it into the barricadoed
58
INSECT TRANSFORMATIONS.
nest of the mason wasp. But although the insect
appeared not to be disturbed by my observations, yet
1 was unable to perceive whether the toothed portion
of the borer was pushed beyond the sides of the sheath.
What I did see, however, convinced me that the in-
strument was worked in a manner well adapted to
make its way through the mortar; for she turned it
half round alternately from right to left and from left
to right, as a carpenter would his brad-awl, and
employed altogether more than a quarter of an hour
before she succeeded in penetrating to a sufficient
depth.'*
Ichneumon flies ovipositing, a a, an ichneumon fly. & 6, its
ovipositor, c, an ichneumon, which has just bored through the
closed substance of a sand wasp's nest at < , into which her ovi-
positor, d, descends to the coil of caterpillars at/, where the
egg is laid.
t Reaumur, Mem. vi, p. 304.
PARASITE EGGS. 59
Another parasite (Pimpla strobikllce, FABR.) is
armed with a long ovipositor, with which it deposits
its eggs in larvae, that burrow in the fruit-cones of
the fir.
The intrusion of these parasite eggs into the nests
of insects is often an exceedingly puzzling circum-
stance to naturalists, in their earlier researches; and
sometimes even deceives those of considerable expe-
rience and acuteness into the supposition that the
insects ultimately produced are in reality those of
the original builder of the nest. These deceptions
frequently occur in the numerous species of vege-
table galls, originating chiefly in the economy of a
beautiful family of insects (Chalcididce, WEST WOOD).
When the gall-fly ( Cynips) has deposited its eggs on
the bud or the leaf of a plant in such a manner as to
insure their being surrounded with a thick coating of
vegetable substance, they are not on that account se-
cure from the insects just alluded to; for the Chalets,
armed by nature with an instrument for the purpose,
can penetrate in any direction the largest oak-apple
or bedeguar of the rose.* The most obvious distinc-
tion between these parasites and the true gall-flies, is,
that in the latter the ovipositor is partly concealed,
while in the former it is altogether external, like the
ichneumons in the preceding figure ; but this dis-
tinction is of course wanting in the male insects. It
was the observation of different species of insects,
produced in this manner from the same sort of gall,
which betrayed the illustrious Redi into the fanciful
notion of their being generated by a vegetative and
sensitive soul in the plant itself, to which also he attri-
buted the generation of the grubs found in nuts, cher-
ries, and other fruits. ' There is nothing,' as Reau-
mur justly remarks, c more fitted to humiliate the best
reasoners, and to inspire them with a well-founded
* See Insect Architecture, pp. 375 384.
60 INSECT TRANSFORMATIONS.
distrust of novel opinions, than to see a man like Redi,
who had declared open war against popular prejudices,
and successfully combated many of them, thus adopt-
ing a notion so improbable, or (to use a stronger term)
so pitiable.'* It was Redi's countryman, Malpighi,
who first discovered the genuine history of gall-flies;
but when we consider that from the bedeguar gall of
the rose alone no less than three different species of
insects may proceed, two of which (Callimone bede-
guaris, and Eurytoma stigma, STEPHENS) are para-
sites, Redi had some cause for being puzzled to ex-
plain the phenomena.
Two other distinguished naturalists, Goedart and
Ray, found no less difficulty in accounting for the
progeny of ichneumons issuing from the caterpillars
and chrysalides of butterflies. Ray, indeed, lived to
ascertain the fact; but he was at one time inclined to
believe, with Goedart, that when, from any defect
or weakness, Nature could not bring a caterpillar to
a butterfly, in order that her aim might not be en-
tirely defeated, she stopped short, and formed them
into insects of a smaller size, and less "perfect struc-
ture. f M. Goedart even persuaded himself, says
Rc-aumur sarcastically, that he had observed the ca-
terpillar interesting itself for its infant progeny, by
weaving for them an envelope of silk. It was also
fancied that what was wanting in size in the parasite
flies, when compared with the expected butterfly j was
made up in their greater numbers ;J with as much
probability, says Reaumur, as that a cat would kitten
a number of mice. The simple facts which we shall
now state, will point out the origin of these strange
mistakes.
* Reaumur, Mem. iii, p. 476.
t Ray, Hist. Ins.,Pref. xv, and Cant. 137.
j Goedart, quoted by R c aumur, vol. ii, p. 415.
PARASITE INSECTS. 61
It must have occurred to the least attentive obser-
vers of the very common cabbage caterpillar (Pontia
Brassicce), that when it ceases to feed, and leaves its
native cabbage to creep up walls and palings, it is
often transformed into a group of little balls of silk,
of a fine texture and a beautiful canary yellow colour;
from each of which there issues, in process of time, a
small four-winged fly (Microgaster glomeratus, SPI-
JNOLA), of a black colour, except the legs, which are
yellow. By breeding these flies in a state of confine-
ment, and introducing them to some cabbage caterpil-
lars, their proceedings in depositing their eggs may be
observed. We have more than once seen one of these
little flies select a caterpillar, and perch upon its back,
holding her ovipositor ready brandished to plunge be-
tween the rings which she seems to prefer. When
she has thus begun laying her eggs, she does not rea-
dily take alarm; but, as Reaumur justly remarks, will
permit an observer to approach her with a magnifying
glass of a very short focus. Having deposited one
egg, she withdraws her ovipositor, and again plunges
it with another egg into a different part of the body of
the caterpillar, till she has laid in all about thirty eggs.
It is not a little remarkable, that the poor caterpillar,
whose body is thus pierced with so many wounds, seems
to bear it very patiently, and does not turn upon the
fly, as he would be certain to do upon another cater-
pillar should it venture to pinch him; a circumstance
by no means unusual. Sometimes, indeed, he gives
a slight jerk, but the fly does not appear to be at all
incommoded by the intimation that her presence is dis-
agreeable.
The eggs, it may be remarked, are thrust suffi-
ciently deep to prevent their being thrown off when
the caterpillar casts its skin; and, being in due time
hatched, th4pgnibs feed in concert on the living
body of the caterpillar. The most wonderful circum-
VOL. vi. 6
62 INSECT TRANSFORMATIONS.
stance, indeed, of the whole phenomenon, is the in-
stinct with which the grubs are evidently guided to
avoid devouring any vital part, so that they may not
kill the caterpillar, as in that case it would be useless
to them for food. When full grown, they even eat
their way through the skin of the caterpillar without
killing it; though it generally dies in a few days with-
out moving far from the place where the grubs have
spun their group of silken cocoons in which to pass the
winter.
Generation of Ichneumons. a, the caterpillar a^^ontia Brassier.
6, the eggs of that butterfly glued to a leaf, c, Mid^Juster glomeratus,
magnified, d d d, a magnified view of a dissected caterpillar, in whose
body a number of ichneumon caterpillars have been hatched, e, silk co-
coons spun by the ichneumons. /, grabs spinning cocoons. -, grub*
eating their way out of the caterpillar.
PARASITE INSECTS. 63
But it is not only in the nests of bees and wasps, or
in the bodies of caterpillars, that these provident mo-
thers contrive to deposit their eggs; for many of them
are so very minute, as to find in the eggs themselves
of larger insects a sufficient magazine of food for their
progeny ; and accordingly, piercing the shell with their
ovipositor, they thrust their own into the perforation.
The most common instance of this which we have re-
marked, occurs in the eggs of spiders; patches of
which may be found almost everywhere under the cross
bars of palings, and the copings and corners of walls.
Though spiders, for the most part, not only cover their
eggs with a thick envelope of silk, but also remain near
to protect them from enemies, yet a small four winged
fly (Cryptus, FABR.), and, if we are not mistaken,
two-winged flies (Muscidce, LEACH), also, outbrave
the danger of being caught and immolated by the mo-
ther spider, and introduce their eggs either into or
among those of their powerful enemy. These spiders'
eggs are subsequently feasted upon by the progeny of
the flies, a very natural reprisal for the ravages
committed by this carnivorous race upon the whole
generation of their fellows. That the mother flies ac-
tually pierce the eggs of other insects was observed
before the year 1730, by the accurate Vallisnieri, who
says, ' I have seen with my own eyes a certain kind
of wild flies deposit their eggs upon other eggs, and
bore and pierce others with an ovipositor (aculeus),
by means of which they have introduced the egg.'*
Count Zinanni, another Italian naturalist, told Reau-
mur, that, his attention being attracted by a small
ichneumon fluttering about the eggs of butterflies,
he soon observed it alight and fix upon one of these
eggs ; and, without being incommoded by his ob-
serving her proceedings through a strong magnifier,
* Vallisnieri, Lettere, 80.
64 INSECT TRANSFORMATIONS.
she bent her ovipositor, and plunged it into the egg.
She performed the same operation upon many other
eggs, which he carefully put under cover; and in about
three weeks had from them a brood of flies of the same
species with the one whose remarkable proceedings he
had watched.*
A writer in the Magazine of Natural History (Jan.
1830), gives an account of a numerous brood of a
very minute species of ichneumon, supposed to be an
egg parasite (Platygaster ovulorum ? STEPHENS),
which was produced from the caterpillars of the large
white cabbage butterfly (Pontia Brassicce). Having
enclosed a number of these in a wire cage, five or six
of them soon left off feeding, and crawled about the
cage. * June 30,' he proceeds, c I found them rest-
ing on large clusters of minute cocoons of an ovate
form, the largest not exceeding two lines in length, and
about the thickness of a caraway-seed. Each was en-
veloped with a fine yellow silk, resembling that of the
common silkworm (Bombyx Mori). On these clus-
ters the caterpillars remained the whole day without
moving. Fresh leaves were given to the rest; but in
the course of the day they all left off feeding, crawled
about the cage, but underwent no other change.
Early next day, I found they had, with the exception
of two or three, all ejected the parasitical progeny they
had been impregnated with; and, like the preceding
caterpillars, continued resting on the clusters they
had formed: the remaining three followed the ex-
ample of the others; and the last operation of these
devoted caterpillars was to envelope each cluster in
a veil formed of the most delicate web.'")" It is
not a little interesting to remark, that this circum-
stance corroborates the statement before given from
* Reaumur, Mem. vol. vi, p. 297.
t Loudon's Mag. Nat. Hist, iii, 51.
PARASITE INSECTS. 65
Goedart, and disbelieved by Reaumur and subse-
quent naturalists: but we think it so very extra-
ordinary, that we are much inclined to think the
observer (T. H. of Clapham) has unwittingly fallen
into mistake. ' Some of them,' he continues, ' ex-
ecuted the task; but the greater part were too feeble
to complete it; and in the course of three days
more they became motionless, and gradually, one
after another, fell shrivelled and exhausted to the
bottom of the cage.' Some of the clusters contained
upwards of a hundred cocoons, and others not more
than sixty. By July 12, the perfect flies made
their appearance by opening a sort of lid at the end
of each cocoon. The flies seem to differ little,
except in size, from the common ichneumon of the
same caterpillar (Micro gaster glomeratus ;) but, sup-
posing them to be in the first instance egg parasites,
they must have been deposited among, not in the
eggs of the butterfly.
The minuteness of some of these parasite insects
may be partly conceived from the fact mentioned by
Bonnet, that the egg of a butterfly, not bigger than
a pin's head, is sufficient to nourish several of them;
for out of twenty such eggs of butterflies, a pro-
digious number (une quantite prodigieuse) were
evolved.* Few species of the plant-lice (Aphides)
are a great deal larger than the butterfly's eggs de-
scribed by Bonnet; yet these also have a parasitical
enemy (Microgaster dlphidum, SPIN OLA), which
plunges its eggs in their bodies; but the larvaB,
when hatched, are by no , means safe, being liable
to the attacks of ^bother fly of the same family
(Gelis agilis, THUNBERG), as Dr Turton informs
us.|
* Bonnet, CEuvres, Svo, ii, 344. Kirby, referring to this
passage, assigns, by mistake, only two to each egg. Introd.
i, 342.
t Transl. of Linn, iii, 48.
VOL. VI. 6*
66 INSECT TRANSFORMATIONS.
It is not common, however, for the ichneumon
flies to deposit their eggs in the bodies of perfect
insects, as in most cases they prefer the eggs, larvae,
or pupae; but instances are on record of their grubs
having been found in the former. The troublesome
cock-roach (Blatta) is selected by a parasite fly
(Evania apendigaster, FABR.), as remarkable in
form as it is rare in occurrence, in Britain at least.
It has been found in the vicinity of London; but,
were it abundant, it might tend to reduce the num-
bers of these black beetles, as they are incorrectly
termed, the pests of the kitchen.
Magnified view of a parasite fly (Evania apendigaster).
An insect parasite, still more singular in form,
and of still rarer occurrence, was discovered by
Kirby, above thirty years ago, on the black bronze
bee (Jlndrena nigrocenea, STEPHENS). ' I had pre-
viously,' he remarks, more than once observed
upon other species something that I took to be a kind
of Jlcarus which appeared to be immovably fixed
just at the inosculations of the dorsal segments of the
abdomen. At length, finding three or four upon a
specimen of this bee, I determined not to lose the
opportunity of taking one off to examine and de-
scribe; but what was my astonishment, when, upon
my attempting to disengage it with a pin, I drew
forth from the body of the bee a white fleshy larva,
PARASITE INSECTS. 67
a quarter of an inch in length, the head of which I
had mistaken for an acarus! (bee-louse). After I
had examined one specimen, I attempted to extract
a second; and the reader may imagine how greatly
my astonishment was increased, when, after I had
drawn it out but a little way, I saw its skin burst,
and a head as black as ink, with large staring eyes
and antennae, consisting of two branches, break forth,
and move itself briskly from side to side. It looked
like a little imp of darkness just emerged from the
infernal regions. My eagerness to set free from its
confinement this extraordinary animal may be easily
conjectured. Indeed I was impatient to become
better acquainted with so singular a creature. When
it was completely disengaged, and I had secured it
from making its escape, I set myself to examine it as
accurately as possible; and I found, after a careful
inquiry, that I had got a nondescript, whose very
class seemed dubious.'* Of the manner in which
this singular insect (Stylops) introduced its eggs
into the body of a bee nothing is yet known, and its
rarity puts it out of the reach of the most eager
observers. Several species of the same genus have
since been found near London, and an allied genus
(Xenos) has since been discovered parasite in wasps
by Professor Peck, in America.
Bee Parasite. (Stylops Melittce, Kirby.)
De Geer was one day much surprised to ob-
serve a small white grub sucking the body of a young
spider (Epeira diadema), having attached itself
* Monogr. Ap. Angl. ii, 113.
68 INSECT TRANSFORMATIONS.
firmly to the abdomen. Having put it into a glass,
he remarked a few days afterwards, that the spider
had spun the outline of a vertical web, had stretched
threads from the top to the bottom, and from one
side to the other of the glass, together with the rays
of a net, but without the circular threads. The most
singular circumstance was, that the parasite grub was
suspended in the centre of this web, where it spun its
cocoon, while the exhausted spider had fallen dead to
the bottom of the glass.*
These examples will suffice to prove the anxious
care of the mother insects in depositing their eggs
where their progeny may find abundance of food.
The tact with which they discover this is one of those
mysteries of nature which are apparently beyond
the penetration of man ever to discover; for it is
seldom that the mother insect herself feeds upon the
game, or similar substances, as her larva?, and yet
she is well aware of what is appropriate for them.
The ichneumon flies, whose history we have just
been sketching, eat little, except, perhaps, a small
quantity of honey from the nectary of a flower,
and yet they know that their progeny must be
fed by living insects; the butterflies and moths,
whose scanty repast also consists solely of the honey
of flowers, never make a provision of this for their
caterpillars, but deposit their eggs on plants and
trees where their young may eat abundantly of
leaves or other parts c after their kind.' In making
these selections, each species exhibits some pecu-
liarity well worthy of observation. Some confine
themselves to one particular sort of plant, and never
select any other; some make choice indifferently of
two or three sorts; while others take a wider range,
and fix upon plants of very different qualities. To
exemplify this, we might mention some thousands of
* De Geer, Memoires, vol. ii, p. 863.
LOCALITIES OF VARIOUS SPECIES. 69
instances, but it will be sufficient to say, that we never
find the eggs of the small tortoise-shell butterfly
(Vanessa urticce) on any plant but the nettle; its
congener, the painted lady (Cynthia cardui, STE-
PHENS), though it prefers the spear-thistle, is some-
times found on the nettle, as is the comma ( Va-
nessa C. JUbuni), though it seems to prefer the hop;
while we have found the eggs of the lackey moth
(Clisiocampa ntustria) on almost every bush and
tree, from the sweetbriar to the oak, in woods,
hedges, orchards, and gardens, without any apparent
preference beyond the accident of the mother moth
alighting on a particular branch. In the same way
almost all those which deposit their eggs on salad
plants, such as the great tiger (Jlrctia, Caja, STE-
PHENS), will as readily select the nettle as the lettuce
or dandelion.*
It is worthy of remark that our native insects fre-
quently make choice of exotic plants, by means of
the instinctive tact which enables them to discover
such as suit their purpose. The death's-head hawk
moth (Jlcheronlia Jltropos), for example, is now
usually found on the potatoe and the jasmine, but
previous to the introduction of these into Britain, it
probably confined itself to the bitter sweet ( Solanum
dulcamara). We have known the moth taken in
Ayrshire, where this plant is abundant. An instance
in point has just occurred to us in one of the minute
leaf-miners. Upon the leaf of an exotic plant
(Cineraria cruenta) kept in a garden-pot in our
study, we were not a little surprised to observe the
tortuous windings of a miner, considerably different
in the outline from any we had before examined.
Though it was so late as December, also, the grub
seemed very active, and would sometimes mine nearly
half an inch of the leaf in the course of the day. It
* J. R.
70 INSECT TRANSFORMATIONS.
was transformed within the leaf, in a few days, into
a pupa, and being put under a bell-glass, a small two-
winged fly (Tephrilis Serratulce? ) made its appear-
.ance in about a fortnight. In some garden-pots, in
another room of the same house, were exotic plants
of the American groundsel (Senecio elegans}, the
leaves of which were crowded with miners, whose
paths, however, were so very different as to indicate
a different species; but upon their transformation
into perfect insects, they turned out exactly the same.
They proved, indeed, to be the same with the leaf
miners of the swine-thistle (Sonchus oleraceus),
Leaf-mining . maggots, a, the fly (Tephritis Serratula ?) 6,
mined leaf of sow-thistle (Sonchus oleraceus). c c, mined leaf
pf Senecio clegans, d <Z, mined leaf of Cineraria entente.
LOCALITIES OF VARIOUS SPECIES. 71
numerous specimens of which we collected in the
immediate vicinity; but the flies of these, from their
previous exposure to the cold out of doors, did not
appear till a month later. It is worthy of remark,
that the two exotic plants are of the same natural
family (Composites) , yet, notwithstanding the simi-
larity of the common groundsel (Senecio vulgaris) to
the American, not one leaf of the former was found
mined, though it is an abundant native plant.*
It is no less remarkable, that the mother insects
of the larvas which live solitary and those which
live in society take care to deposit their eggs with
regard to the respective destinations of their pro-
geny. In our earlier studies we remember being much
interested with Harris's description of the admirable
butterfly ( Vanessa Jltalanta)^ flitting rapidly and
stealthily from field to field, and depositing only a
single egg on a single nettle in each, as if she were
afraid of overstocking one place and leaving others
uninhabited by her descendants.! Our subsequent
observation of the mariners of the insect itself has led
us to doubt the accuracy of Harris; for we think it
will hold as a pretty general principle, that the mo-
thers of solitary caterpillars, for the most part, deposit
several eggs on the same plant, often at no great
distance, and sometimes on the same leaf. No class
of caterpillars could well be considered more solitary
than those of the hawk moths (Sphingidce, LEACH),
yet we have found from two to three eggs of that
of the popular hawk ( Smerinthus Populi) upon the
same leaf, and a similar number of the eggs of the
puss moth, the larva of which is also solitary, on one
leaf ;J while of the admirable butterfly above alluded
to, we found, in 1825, as many as from three to six
on every plant in a small patch of about a dozen
* J. R. t See Harris's Aurelian, vi, fol. Lond. 1778.
| See Insect Architecture, p. 192.
72 INSECT TRANSFORMATIONS.
nettles, in Copenhagen-fields, Islington. A similar
deposition of eggs is made by several of the mothers
of the subsolitary caterpillars which live in the wood
of trees. Of this we had a good example in the
clear under-wing (JEgeria asiliformis) , above a score
of the small black eggs of which we found deposited
in a scattered manner on the trunk of a single poplar
at Lee.*
The most singular disposal of eggs with which we
are acquainted in the economy of insects, is exempli-
fied in the common gnat ( Culex pipiens, LINN.) It
is admirably described by Reaumur, though it seems
first to have been discovered by Langallo, who men-
tions it in a letter addressed to Redi, printed at Flo-
rence in 1679 ; and by Alloa, who actually saw the
eggs laid, and afterwards sketched a figure of them.
Those who wish to witness this singular operation,
must repair before five or six o'clock in the morning
to a pond or a bucket of stagnant water frequented by
gnats ; when Reaumur went later in the day he was
always disappointed.
The facts of this disposal of her eggs by the com-
mon gnat, are sufficiently curious to excite attention
to them ; and, therefore, it is not easily to be under-
stood how the following erroneous and fanciful
account originated. ' The manner,' says Gold-
smith, * in which the insect lays its eggs is particu-
larly curious ; after having laid the proper number on
the surface of the water, it surrounds them with a
kind of unctuous matter, which prevents them from
sinking, but at the same time fastens them with a
thread to the bottom, to prevent their floating away,
at the mercy of every breeze, from a place the warmth
of which is proper for their production, to any other
where the water may be too cold, or the animals, its
enemies, too numerous. Thus the insects, in their
* J. R.
RAFT OF EGGS OF THE GNAT. 73
egg state, resemble a buoy which is fixed by an
anchor. As they come to maturity, they sink deeper,
and at last, when they leave the egg as worms, creep
to the bottom."** This fable, which was first men-
tioned by Pliny, is repeated verbatim by JBingley.'f
The impossibility of a gnat spinning a thread, and
plunging into the water to fix it at the bottom, never
struck these writers.
We are more anxious to expose these erroneous
accounts, from a persuasion that a taste for natural
history has been more injured by numerous similar
statements, which could not be verified by a student,
in many popular works, than by the driest skeleton
descriptions of those who have merely pursued Natural
History as a science of names.
The problem of the gnat is to construct a boat-
shaped raft, which will float, of eggs heavy enough to
sink in water if dropped into it one by one. The
eggs are nearly of the pyramidal form of a pocket
gunpowder-flask, rather pointed at the upper and
broad at the under end, with a projection like the
mouth of a bottle. The first operation of the mother
gnat is to fix herself by the four fore-legs to the side
of a bucket, or upon a floating leaf, with her body
level with and resting upon the surface of the water,
excepting the last ring of the tail, which is *la little
raised ; she then crosses her two hind legs in form of
an X, the inner opening of which is intended to form
the scaffolding of her structure. She accordingly
brings the inner angle of her crossed legs close to the
raised part of her body and places in it an egg, covered,
as is usual among insects, with a glutinous fluid. On
each side of this egg she places another, all which
adhere firmly together by means of their glue, and
form a triangular figure thus J *, which is the stern
* Goldsmith, Animated Nature, vi, 337.
t Bingley, Animal Biography, iii, 439, Sd.ed.
7
74 INSECT TRANSFORMATIONS.
of the raft. She proceeds in the same manner to add
egg after egg in a vertical (not a horizontal) position,
carefully regulating the shape hy her crossed legs;
and as her raft increases in magnitude, she pushes the
whole gradually to a greater distance, and when she
has about half-finished she uncrosses her legs and
places them parallel, the angle being no longer neces-
sary for shaping the boat. Each raft consists of
from two hundred and fifty to three hundred and
fifty eggs, which, when all laid, float on the water
secure from sinking, and are finally abandoned by
the mother. They are hatched in a few days, the
grubs issuing from the lower end; but the boat, now
composed of the empty shells, continues to float till it
is destroyed by the weather.*
Gnats forming their egg boats, a, represents the commencement
of the boat of eggs ; 6, the boat about two-thirds completed j c,
the perfect boat resting on the surface of the water.
Kirby justly describes this little vessel as resembling
a London wherry, being sharp and higher, as sailors
say, fore and q/, convex below and concave above,
and always floating on its keel. ' The most violent
agitation of the water,' he adds, c cannot sink it, and
what is more extraordinary, and a property still a de-
sideratum in our life-boats, though hollow, it never be-
* Reaumur, Mem, iv, p. 621.
RAFT OF EGGS OF THE GNAT. 75
comes filled with water, even though exposed. To
put this to the test, I placed half a dozen of these
boats upon the surface of a tumbler half-full of water:
I then poured upon them a stream of that element
from the mouth of a quart bottle held a foot above
them. Yet after this treatment, which was so rough
as actually to project one out of the glass, I found
them floating as before upon their bottoms, and not a
drop of water within their cavity.'* We have re-
peatedly pushed them to the bottom of a glass of wa-
ter; but they always came up immediately to the sur-
face apparently un wetted.
Magnified view of the boat of gnats' eggs.
We have contented ourselves with giving here only
a few examples of the maternal care which is display-
ed by insects in depositing their eggs, though we
could have filled the volume with similar details.
The instincts which are thus displayed are of the
most interesting description; and they cannot fail to
knpress the most careless observer with a deep reve-
rence of that providential wisdom by which they are
implanted in these small and feeble creatures for the
maintenance of their race. But it is not essential, in
order to produce this reverence, to exaggerate the cir-
cumstances under which these remarkable peculiari-
ties are displayed. The infallibility of the instinct of
insects in such cases is, in most books of natural his-
tory, maintained to be without exception. < Led by
an instinct,' says Kirby and Spence, < far more un
* Introd. iii, p. 32.
76 INSECT TRANSFORMATIONS.
erring than the practised eye of the botanist, she re-
cognizes the plant the moment she approaches it.'*
And again, they talk of the c unerring foresight with
which the female deposits her eggs in the precise
place where the larvae when excluded are sure to find
suitable food.'t This unconditional position requires
however, to be considerably modified to make it cor-
respond with the facts. The experiment we gave from
Redi in our first chapter, in which the carnivorous
flies laid their eggs on the silk and paper covering
tainted meat, will occur to every reader as one striking
exception; and we can mention several others still
more marked. When Dr Arnold discovered that
most singular parasitic plant, the krubut, of Sumatra,
(Rafflesia Jlrnoldii, BROWN,) which consists of a
flower only, without leaf or stem, and of the extra-
ordinary diameter of three feet, he perceived a swarm
of flies hovering over the nectary, an?, apparently
laying their eggs in its substance, mistaking it most
probably for carrion, as it smelt like tainted beef.J
A similar mistake is committed in ,ur own country,
when the cc union blow-fly (Muse/, vom'toria) lays
its eggs in c cetid funguses (Phalli, Agarici, &c),
apparently ; -er the .notion that these are genuine
carrion. This may be more particularly observed
on the singular class of plants, stapelias, which are
so common in our hot-houses: whole families of mag-
gots are constantly born to starve in their foetid flowers.
These are instances of the mistakes of instinct in
circumstances where it depends upon the information
of the senses ; and similar mistakes frequently occur
where the higher powers of human rationality are
deceived by analogous phenomena. The fine nutty-
flavour of cherry laurel water and of prussic acid
* Introd. i, p. 340. t Ibid, iii,.p. 65.
$ R. Brown, Linn. Trans, vol. xiii. $ Smellie, Philos. of
Nat. Hist.
MISTAKES OF INSECTS. 77
would be certain to deceive the inexperienced ; and
Majendie's servant actuality fell an immediate victim
to her desire of tasting the prussic acid which she
found in his laboratory. This would be considered
perhaps a mistake arising from the artificial habits ac-
quired in society, by those who maintain that animals,
guided by instinct, never mistake poison for food. But
we may add another curious instance or two of simi-
lar mistakes in the inferior races.
The common earth-worm (Lumbricus terrestris)
is instinctively afraid of moles ; and no sooner does it
hear any subterranean noise, or feel any shaking of
the ground, similar to those indicative of the approach-
ing movements of its enemy, than it makes a speedy
escape to the surface. Every boy knows how to take
advantage of this to procure fish-baits, by thrusting a
spade or stake into the ground, and moving it backwards
and forwards, to imitate the advance of a mole burrow-
ing in search of prey. The worm, unable from its in-
stinct to discriminate between its subterranean enemy
and the spade, darts into day-light, and is instantly cap-
tured for the boy's bait-bag. The lapwing ( Vancllus
cristatus, MEYER), it is stated by Dr Anderson in his
' Bee, 7 is aware of this instinctive fear in the earth-
worm of subtewanean concussions or noises ; and
when it cannot find sufficiency of slugs,* &c, above
ground, it pats with its feet, till the earth-worms, mis-
taking it for an advancing mole, come forth to be feast-
ed upon.
It is well known that, whenever a hawk appears,
he is immediately surrounded by a host of small birds,
particularly swallows, which dart at him and tease him,
for the purpose, as maybe supposed, of distracting his
attention, on the principle that * wealth makes wit wa-
* Nourriture ; insectes, araign? es, vers, et petits lima
Sons.' TEMMINCK, Manuel d'Ornithologie, p. 552, 2d edit.
7*
78 INSECT TRANSFORMATIONS.
ver.' Be this as it may, the cuckoo, which bears a
strong resemblance to a hawk when on the wing, is
certain to be accompanied by a similar retinue of small
birds wherever it flies. In the north this is so com-
monly observed, that the cuckoo is popularly believed
to be always attended by a tilling or pippet (Anihus
pralensis, BECHSTEIN), which, it is further imagined,
has been its stepmother and nurse from the egg : this,
indeed, is the bird whose nest the cuckoo most fre-
quently selects to deposit the eggs which she so
strangely and unnaturally abandons; though it is more
probable that it is not on this account, but because she
appears to be a hawk, that the pippet and other small
birds persecute her.
Linnaeus records in his c Lachesis Lapponica,' that
at Tornea there is a meadow, or bog, full of water-
hemlock ( Cicula rirosa), which annually destroys from
fifty to a hundred head of cattle. It seems that they
eat most of it in spring, when first turned into the pas-
ture, partly from their eagerness for fresh pasture, and
partly from their long fasting and greediness, the herb-
age being then short. Besides, from the immersion
of the hemlock under water, it may not have the pro-
per scent to deter them. A similar destruction of cat-
tle from the same cause occurs in th$ wide meadows
of Leinings.*
* J. R., in Mag. of Nat. Hist.,i, 374.
CHAPTER IV.
Hibernation of Insect Eggs. Ingenuity of Moths. Singularities of
Cochenille Insects and of Spiders. Experiments of Spallanzani and
John Hunter.
THE assertion of Paley that the human animal is
the only one which can clothe itself,'* though it ac-
cords with what is known of quadrupeds, birds, and
fishes, by no means holds good in the insect world, in
which it may be disproved by the most superficial
observer.^ Men, indeed, proceed by means of rea-
soning and. experiment to the discovery of such ma-
terials as a're best fitted for protecting their bodies
against the vicissitudes of temperature, and other
changes of weather ; while insects are taught by the
Governor of the Universe to select instinctively the
best materials for their clothing. This is exemplified
in a very remarkable manner in the coverings made
by different families for protecting their eggs, as we
shall now describe.
The maternal affection of the eider duck (Jlnas
mollissima, LINN.) has frequently been celebrated by
naturalists, from her stripping the down from her own
breast to form her nest, a circumstance which is also
exemplified in the common rabbit ; but both of these
animals are outrivalled by more than one moth :
for the latter, not contented with a nest made of their
own down, take pains to cover with it each individual
egg. The provision which nature has made for this
purpose is worthy of attention. The female, for ex-
ample, of the gypsey moth (Hypogymna dispar) has
the hinder parts of her body thickly clothed with a
* Natural Theology, p. 230, llth edit.
t See Insect Architecture,* chaps, x, xii, &e.
80 INSECT TRANSFORMATIONS.
soft down of a hair-brown colour, which is wanting
in the male, evidently because to him it would be of
no use. As a covering for her own body, it can be
of but small service, since she emerges from her
pupa-case during the hot days of August, and does
not usually live more than a week or a fortnight. Its
chief or sole purpose, therefore, is to furnish a cover-
ing for her eggs.
When about to lay, the mother gypsey moth places
herself on the trunk of an oak or an elm, invariably
with her head downwards, the reason of which posi-
tion will be immediately explained. With the aid
of her legs, which are too short to be used like
those of the gnat by way of rule and compass, she
contrives to place her eggs in the form of an inverted
cone. She first makes a little bed of this down, into
which she thrusts the egg intended for the point of
her cone; and this egg, being covered with adhesive
gluten, attaches around it all the hairs of the down
with which it comes in contact, and also sticks to the
bark of the tree, from its being pushed home. Pro-
ceeding in the same manner, she continues for seve-
ral hours adding to the mass ; but she does not in
general finish the operation in less than two days,
indulging in occasional rests when fatigued with her
labour. At intervals, also, she takes care to protect
the eggs placed in the cone with an exterior covering
of the same down. There is one part of these ope-
rations not a little remarkable. In the bed which she
first makes for the eggs, the hairs of the down either
point at right angles to the bark of the tree, or at
least are tossed down with little regularity ; but in
the external coping, which is designed to keep out the
winter rains, the hairs are carefully placed in a sloping
direction, like the tiles on a house, or the pile of a
well brushed hat, pointing downwards towards the
base of the cone. The latter is usually concave, be-
JNGSNUITY OF MOTHS. 81
cause, when the moth takes her occasional rests, she
never moves from the spot, but remains with her tail
thrust in amongst the eggs. We have given these
details from observations made in the Pare at Brus-
sels, in August 1829;* and our entomological readers
will perceive, that though they do not disagree with
the facts observed by the accurate Reaumur, we have
added several particulars not mentioned by him.!
In order to preserve some specimens of the gypsey
moth, which abounds in the Netherlands, but is rare
in most parts of Britain, we inclosed two or three in
chip boxes. Upon opening these, a short time after-
wards, we found that one of the moths had deposited
a patch of eggs; but, instead of the conical form which
the insect would have chosen had she been at liberty,
she had disposed them in the form of a wheel, of which
her body was the radius. This, of course, was not so
much to be wondered at, as it no doubt arose from her
want of space to proceed in the usual manner; but we
deem it worthy of notice that this wheel, which was
about a quarter of an inch broad in the rim, was sloped
o, female gypsey moth, one-third the natural size, just finish
ing her group of eggs. 6, female gypsey moth, with its body
covered with down, c, circle of eggs covered with hair, and d,
conical mound of eggs covered with hair, laid by gypsey moths
in confinement.
* J. R. t Reaumur, Mem. ii, 101.
82 INSECT TRANSFORMATIONS.
with the greatest regularity, after the manner of a candle
shade, and the down tiled upon it all round. Another
of our prisoners, though precisely in the same circum-
stances as to space, instead of forming a wheel, piled
up her eggs in form of a circular mound; but as the
number of her eggs was not a sixth part of those of the
other, (probably from her having deposited part before
we caught her,) this may have induced her to vary
the shape of the group. Like the others, however,
the regular slope and tiling of the down was carefully
preserved.* We have now (April, 1830) a numerous
brood of caterpillars from these very eggs.
The eggs, which are thus deposited with so much
care, are destined to abide all the pitiless pelting of
the storms of winter; for, although they are laid in
August, they are not hatched till the elm conies into
leaf in the following spring. The covering of down,
accordingly, from the manner in which it is tiled and
brushed smooth by the mother moth, not only protects
them from wet, but from severe cold, being one of the
best non-conductors of heat. The experiments of
modern chemical philosophers have proved beyond a
doubt, that the warmest material for clothing is not
what imparts most heat to the body, but what best
prevents the escape of the heat generated there. The
feeling of cold, therefore, does not, as might be sup-
posed, arise from anything positively cold, but solely
from a deficiency of heat. On putting the hand, for
example, on a piece of ice, the feeling of cold does
not arise from cold given out by the ice to the hand,
but from the heat which the ice takes from the hand,
which heat can be actually traced in the water formed
by the melting of the ice. But when the hand is laid
upon wool, feathers, or down, these do not feel cold,
because they do not carry off the heat of the skin so
rapidly as the ice.
* J. R.
PROTECTION OF EGGS. 83
It may appear a little paradoxical, though the doc-
trine is sound, to assert that down and similar ma-
terials are nearly as well calculated for protecting an
animal from excessive outward heat as from severe
cold. This, however, has been long well known as a
fact to the Neapolitan peasantry, who convey snow
from Mount Vesuvius to Naples in the summer for the
purposes of luxury: they preserve it from melting by
covering it with chaff and wool. It may not be out
of place to remark that instances of this occur among
insects, precisely similar to what we have just detailed
respecting the gypsey moth. The brown-tail and the
golden-tail moths (Porthesia auriflua, and P. Chry-
sorrhcea, STEPHENS), whose caterpillars spin them-
selves a warm nest before the setting-in of the winter
colds,* seem no less careful to protect their eggs from
the summer heats of July and August, at which time
they are deposited. The down with which they are
furnished for this purpose grows upon the tail of the
female moth, in form of a thick tuft or brush, of a
shining silky gloss, and of a different colour from the
short hair on the body. It may be remarked that
moths have only a mouth tube for sucking honey, and
Females of the brown and gold-tailed moths, showing the bunch
of down on the tails.
* See ' Insect Architecture,' p. 329 331.
84 INSECT TRANSFORMATIONS.
no mandibles or jaws,* like bees, wasps, and beetles,
for performing any mechanical labour; but the moths
in question have an organ admirably contrived for
covering their eggs with down. This consists of an
extensile instrument, situated in the tail, not unlike
the points of a pair of sugar-tongs, and intended to
perform the part of tweezers in pulling off the down,
and placing it upon the eggs. Having reared nume-
rous broods of the moths alluded to, we can testify
to the minute accuracy of Reaumur in detailing
their proceedings. He remarks, that though the
mother moth is exceedingly sluggish (lourde) in her
general movements, she employs her tweezers with
surprising quickness, on all sides, first to pull off a
pinch of down, and spread it out, and then to place the
egg upon it, and cover it neatly over, and smooth the
down in the proper direction. The nature of the in-
strument will be better understood by the following
figures.
Tweezers of the brown and gold-tailed moths, magnified.
Reaumur has figured the deposition of the eggs
of an insect, the species of which is not ascertained,
sent him by a physician of Lucon, which are covered,
like the preceding, with down, but are arranged in an
elegant spiral form, as if a lady would wind one of
the ends of her fur tippet spirally round a branch,
* Savigny, however, has displayed much acumen in showing
how the suckers of moths, &c, are analogous to mandibles.
Memoir es sur les Jlnim. sans Verteb.
SPIRAL FORM OF EGGS. 85
These eggs were extremely small, and the down very
fine, like the short fur of the beaver, and of a pretty
squirrel-gray colour. The eggs were oblong, and
placed on end, at right angles to the branch; as was
also their downy envelope, which differed in this re-
spect from the imbricated and smoothly brushed
coping of the moths above described. There is no-
thing of this kind, says Reaumur, which we ought to
consider it difficult for an insect to execute, when we
are acquainted with the admirable instruments with
which nature has furnished them.*
Spiral group of eggs of an unknown moth.
The spiral form of eggs deposited upon a branch
may, in particular years, be seen in almost every
orchard and every hedge, being the method followed
by the lackey moth (Clisiocampa neustria, STE-
PHENS) and its congeners. The precise manner in
which the mother lackey proceeds has not, so far as
we know, been witnessed by any naturalist ; and
though Reaumur reared a great number on pur-
pose to discover it, all his efforts proved unsuccessful.
An examination, however, of the arrangement of the
eggs themselves, shows that they are placed in a
manner excellently adapted to secure their adhesion
to the branch, and to prevent their sustaining injury.
The egg is somewhat of the form of a funnel-shaped
wine-glassbroader at top than at bottom ;| and it
I
* Reaumur, Mem. ii, 107.
i See two of these eggs figured in * Insect Architecture,' p. 19.
8
86 INSECT TRANSFORMATIONS,
is worthy of remark, that this is the precise form of
the arch-stones of a bridge. They are, in fact, built
together in the arched form. This, together with
the strong cement employed in uniting them, renders
it difficult to crush them, though considerable force
be used for that purpose; and this even when they
are slipped off the branch, round which they are set
like pearls on a bracelet,, which is the name given
them by the French peasantry. The cement, also, is
so hard, that when pressed it resists the nail, though
it may be pierced with the point of a sharp knife ; and
not being soluble in water, ' nor in any other liquid,'
says Swammerdam, { which I have tried,' the heavi-
est rain dashes upon the eggs without injury.
Eggs of the lackey moth, wound spirally round a twig of haw-
thorn 5 natural size, and magnified.
It may be a question with some, when they com-
pare these naked eyes of the lackey moth, exposed on
a bare branch, with the warm downy covering of those
of the gypsey moth, how the former are protected
from the colds of winter. This is a question which
previous researches cannot fully answer, but one cir-
cumstance is obvious - the lackey's eggs are many
degrees harder than those of the gypsey, which may
be easily crushed. Probably also, this may be con-
nected with their electrical state; and that has always
HYBERNAT1ON OF EGGS. 87
an intimate connexion with heat in animated bodies.
The living principle, to which we shall by and by
advert, must also be taken into account.
In consequence of the minuteness of insect eggs,
notwithstanding the researches of enthusiastic ento-
mologists, we are still unacquainted with by far the
greater number. The hybernation of eggs is, there-
fore, a subject upon which little is known.. In the
egg state insect life is, perhaps, less liable to acci-
dents, than in a more advanced stage of existence;
and it is most probable that the greater number re-
main unhatched during the cold season. Different
modes of depositing eggs are resorted to by different
species of the same genus, as may be exemplified in
the plant lice (Aphides). It was observed by De
Geer, that those of the birch and the blackthorn
(Aphis Mm, and A. Pruni) covered each egg indivi-
dually with a white cottony down, detached from their
bodies by means of their hind legs, and placed by the
same means over the eggs.* But the greater num-
ber of this family lay their eggs in an exposed situa-
tion, upon the plants where the young, when hatched,
may find food. Thus Kirby found the small black
eggs of a large species on the buds of birch-trees; and
we have just discovered (Jan. 1830) a numerous de-
posit of the eggs of the magpie plant-louse (Aphis
Sambuci) on an elder tree, where the insect was
abundant the preceding summer. "f These eggs are
exceedingly minute, but easily observed on account of
their shining black colour. They are placed in an ir-
regular patch upon the part of a trunk from which the
bark has been stripped off, and are entirely unprotected.
The cochenille insects (Coccidce, LEACH), so called
from one of the species furnishing the well-known
valuable dye-stuff, protect their eggs in a still more
* De Gecr, Mem. sur Ics Insectes, i-ii, 48, 51. t J. R,
88 INSECT TRANSFORMATIONS.
remarkable manner. The mother deposits her eggs
under her body, which becomes glued to the spot; she
then dies, and her body becomes a covering for the
eggs. In this state the insects appear on the bark
of trees like small warts, some species in the form of a
boat, some kidney-shaped, and others globular; and,
before their history was understood, they were with
some plausibility supposed to be vegetable galls,
whence they were termed Gall Insects by the French.
Though the mother insect is seldom larger than a
peppercorn, the number of eggs which she lays
amounts to several thousands, and in fact fills the
greater portion of her body. Those which are found
on our green-house plants, and which are the pest
of the grape-vines in the neighbourhood of London,
both in and out of doors, Secrete a sort of white
silky gum, very like gossamer, as the first bed of
their eggs. Reaumur could not discover that the
mother insect was furnished with any organ similar
to those of spiders and caterpillars for spinning this
gossamer; and in an allied genus (Dorthesia), Kirby
and Spence talk of it as wire-drawn through nu-
merous pores in certain oval plates in the skin.'*
Having minutely observed, during several successive
summers, some thousands of the female cocci found
on vines in the open air, we have satisfied ourselves
that this cottony matter is precisely similar to the
gluten which envelopes the eggs of most insects;
and that it is neither spun like the threads of cater-
pillars, or the webs of spiders, nor wire-drawn
through numerous pores, but is simply excluded
along with the eggs. We may remark, also, that the
covering formed by the body of the mother coccus
prevents this substance from drying, as the webs of
spiders do; and, consequently, it can at any time be
* Introd. iii, p. 183.
EGGS OF THE COCCI.
89
drawn out into extended threads, by detaching a few
of the eggs from the mass.
Eggs of the Coccus covered with down, and with the bodies
of the mothers.
An account, which appears to us altogether apo-
cryphal, has been given of the migrations of the
species which produces the cochenille ( Coccus Cacti,
LINN). From the females remaining stationary, it
is said, their numerous progeny would not find
sufficient nutriment on their native tree; and they
are, at the same time, so delicate, that they could not
travel along the ground from one plant to another;
Magnified cochenille insects, (Coccut cacti). r, Male. 6, Female.
90 INSECT TRANSFORMATIONS.
but nature, it is alleged, provides for them admirable
means of emigration, since, at the period of their
birth, a multitude of spiders fasten their nets to the
leaves of the nopal, and along these, which serve
them for bridges, the young cocci emigrate to the
adjacent trees. * We have little doubt that this story
has originated in the inaccurate observations of some
fanciful traveller, who mistook the threads accidentally
drawn out from the mass of eggs, for those of a
spider.
The gossamer envelope, however, which we have
just described as covering the eggs of the coccus that
is common on our British vines, is not intended as a
defence against the cold of winter; for this species
hybernates, according to Reaumur, in the larva state,
though we have frequently searched for these larvae
in vain during winter, on vines where they swarmed
in myriads during summer. But the British species
of coccus of the hawthorn, &c, on account of which
we introduced the subject here, assuredly hybernates
in the egg state; and may be seen at the off-goings
of the branchlets in an oval form, like that of a
minute wood-louse (Omscws), of a silvery gray
colour, differing, indeed, 'but little from the tint of
the bark. On raising up with the point of a pen-
knife what appeared to be the body of the insect, we
found that it was hard, dry, and dead, the mere
skin, in a word, of the mother coccus, while under-
neath was a multitude of eggs of a deep orange
colour. It is worthy of notice, also, that there is,
then, no envelope of gossamer, though there is mixed
up with the eggs a small quantity of a grayish white
powder, which, we are inclined to conjecture, may
be the dried remains of it; and, the more so, that
Reaumur figures the gossamer as abundant in the
coccus of the hawthorn. Unfortunately he has not
* St Pierre, Studies of Nature, vol. i.
EGGS OF THE COCCI.
91
mentioned at what season he procured these, and we
have no means of ascertaining whether our species is
the same with his.*
a 6 c, Eggs of the hawthorn coccus, covered by the body of the
dead mother, d, one of these magnified, e, a section, showing
the eggs within.
We have found the eggs just mentioned most
abundant on the hawthorn in the hedges around
London; but as the size, the colours, and the forms
of the crust are very different, there can be no doubt
of there being different species even on the same
tree. ' In July, 1812,' says Rirby, <I saw a cur-
rant-bush miserably ravaged by a species of coccus
very .much resembling the coccus of the vine. The
eggs were of a beautiful pink, and enveloped in a
large mass of cotton-like web, which could be drawn
out to a considerable length. '| From the manner in
which this justly popular author speaks, it would ap-
pear he had not elsewhere met with this coccus; but
* J.R.
t Intr. i, 197.
92 INSECT TRANSFORMATIONS.
it is by no means of rare occurrence, and may be
found on most currant-bushes, and often on hawthorns,
&c, around London. The envelope of the eggs is
of a chestnut-brown colour.
A much more singular species occurs in company
with the preceding, and abounds on the currant-
bushes at Lee. From their resemblance to the form
of one of the valves of a mussel-shell, Reaumur
named this species en coquille ( Coccus conchiformis,
GMELIN). He says, it imposed upon him for several
years, as he supposed it to be the cocoon of some
minute insect about to go into the pupa state; but he
was undeceived by finding them full of eggs. We
were more disposed, at first, to look upon them as a
subcortical fungus (such as Cucurbitaria Berbemdis,
GREV. or Cryptosphceria Pteridis, So WERE.), for,
during the winter, when we first observed them, they
appeared exactly like a little slip of the bark elevated
by the growth of a fungus below it. Then they were
so crowded on some branches, that not a hair's breadth
of the bark remained uncovered. When, however,
we found these minute bark-like scales full of eggs, we
were inclined to conjecture that they had been depo-
sited by saw-flies cutting into the bark; but this was
instantly disproved by removing them, and finding the
bark below sound and uncut. Reaumur put the
matter beyond dispute by actually hatching the
eggs, when insects were produced similar to other
cocci. But our species, found on the currant-bush,
seems to differ from his of the elm, not in form and
colour, but in habit, being gregarious, while his was
subsolitary.*
During the severe frost of 1829-30, we observed
several small birds, such as the long-tailed titmouse
(Parus caudatus), and the gold-crested wren (Regu-
* J. R.
DEPOSITIONS OF EGGS. 93
lus cristatus, RAY), busily pecking the eggs of the
cocci in the hedges.*
The resemblance of these singular insects to the
wood-louse (Oniscus), which is not properly an in-
sect, but a crustaceous animal, may be traced farther
than mere external appearance; for the body of the
mother, in the latter, also becomes a covering for
the egg, though she does not die immediately after
laying as the coccus does, but carries her eggs under
her breast in small four-valved cells.
One of the most easily discovered depositions of
eggs during the winter months are those made by
various species of spiders, particularly that of the
large garden-spider (Epeira diadema), which may
be found in the angles of walls, in form of a ball,
about the size of a cherry, of beautiful yellow silk,
and much stronger than the common materials of the
same spider's geometric web. This substance Reau-
mur endeavoured to bring into use as a substitute for
silk; but he was unsuccessful in procuring it in quan-
tity, owing to the ferocious habits of the spiders,
which devoured one another when he reared them
gregariously. As the eggs of spiders have usually a
thin soft shell, a thick warm envelope of silk is, no
doubt, essential to their weathering the colds of winter,
notwithstanding the sheltered corners where they are
usually placed. Some species weave these little silk-
en nests in a very elegant form. We possess one
of the pyriform shape of a balloon, the texture of
which is close and netted with diagonal meshes. One,
somewhat in form of a drinking-glass, is figured in
Loudon's Magazine of Natural History, as having
been found near Wandsworth, attached to the stem
of a rush growing in water.
There was a deposition of eggs at the bottom, the
rest of the space being vacant. De Geer describes
* J. R.
94
INSECT TRANSFORMATIONS.
similar spiders' nests attached to the stems of grass;*
and we once found a large one of an elongated shape,
and composed of very white silk, en a spike of grass
at Compton-Basset, Wiltshire.!
Spiders' nests.
The vapourer ( Orgyia antiqua, OcnsENH.),a com-
mon moth, takes, advantage of the warm silken enve-
lope of the pupa-case, from which she has escaped a
few days before, to form a bed for her eggs. In our
earlier studies of insect economy we were inclined to
ascribe to accident the deposition of the eggs in this
particular situation, but we have found so many in-
stances of it as to reject the explanation. Swammer-
dam also observes, that ' this custom of fastening
the eggs to the web in a constant method, and
by the immutable law of nature, is so peculiar to
this species of insects, that I have never obser-
ved it in any other kind whatsoever. This fe-
male,' he subjoins, i like a most prudent house-
wife, never leaves her habitation, but is always
fixing her eggs to the surface of the web out of
which she has herself crept, thus affording a beau-
tiful instance of industrious housewifery. 'J One
De Geer, Mem., vol. vii, pp. 227 9.
| Swammerdam, pt ii, page 7.
t J. R.
DEPOSITIONS OF EGGS. 95
reason for this is, that the female of this moth
having only the rudiments of wings, a peculiarity
remarkable in several other moths, she cannot shift
so readily about. But whatever may be the real
cause, there can be no doubt that the web serves to
keep the eggs warm during winter; for though they
are placed on the outside of the web, the whole is
usually under some projection x>f a wall or arm of a
tree, and the non-conducting property of the silk,
both with regard to heat and electricity, must be of
great benefit to the eggs in preserving them in an
equable temperature, and of course promoting their
early hatching.
Vapourer Moth. (Orgyia antiqua), male and liemale, the latter
without wings j with the eggs laid upon the silken cocoon from
which the mother has issued.
We cannot better conclude these imperfect sketches
of the hybernation of insect eggs, than by an ac-
count of the ingenious experiments made by Spal-
lanzani and John Hunter, by exposing several spe-
cies of these to great degrees of cold as well as
of heat. It results from these experiments that
* intense cold,' to use the words of Spallanzani,
6 does not destroy the eggs of insects. The year
1709, when Fahrenheit's thermometer fell to 1,
is celebrated for its rigour and its fatal effects on
plants and animals. Who can believe, exclaims
Boerhaave, that the severity of this winter did not
destroy the eggs of insects, especially those exposed
to its influence in the open fields, on the naked
96 INSECT TRANSFORMATIONS.
earth, or or on the branches of trees ? Yet, when the
spring had tempered the air, these eggs produced as
they usually did after the mildest winters. Since that
period there have been winters more severe. In
France, during December, 1788, the thermometer
fell considerably lower, and in several other tempe-
rate European climates.
' I have exposed eggs to a more rigorous trial
than the winter of 1709. Those of several insects,
and among others the silk- worm, moth, and elm
butterfly ( Vanessa polychloros ?) were enclosed in a
glass vessel and buried five hours in a mixture of ice
and sal gem (rock salt), the thermometer fell 6
below zero. In the middle of the following spring,
however, caterpillars came from all the eggs, and
at the same time as from those that had suffered no
cold. In the following year, I submitted them to an
experiment still more hazardous. A mixture of ice
and sal gem with the fuming spirit of nitre (Nitrate
of Ammonia), reduced the thermometer 22 below
zero, that is 23 lower than the cold of 1709.
They were not injured, as I had evident proof by
their being hatched.
' Combining all these facts, we conclude that cold
is less noxious to germs and eggs, than to animalcula
and insects. Germs in general can support 2 be-
low zero; whereas of animalcula some die at the
freezing point, and some at about 20. The eggs
of many insects continue fertile after being subjected
to a temperature of 22 below zero, while insects
themselves die at 16 and 14. This I have ascer-
tained in the eggs of the silk-\vorm moth and of the
elm butterfly; and although there are caterpillars
and chrysalides able to resist great cold, I have uni-
formly found it to be in a less degree than what can
be resisted by their eggs. What can be the cause of
so great a difference? Insects killed at 16 and 14
EFFECTS OF COLD UPON EGGS. 97
are so penetrated and frozen by the cold, that their
members do not yield to the pressure of the finger,
and seem perfect ice under the knife. This does
not happen to eggs, though subjected to cold of much
greater intensity. Their contents remain fluid, even
at the greatest cold, as may be seen by crushing them
with the nail. Perhaps this is derived from constitu-
ent spirituous or oleaginous parts, or from some prin-
ciple adapted to abate the power of cold.* If eggs
do not freeze, it is probable the included embryos do
not freeze. ' Is there anything wonderful, therefore,
that they then survive cold which is fatal to them
when produced ? * Probably for the same reason (and
I see no objection that can apply), animalcula, con-
centrated in the germ, can support a degree of cold
they are incapable of when developed.
* As the temperature of freezing still retains a
portion of heat, why, it may be asked, should it not
develope the germs of the most minute animalcula?
Had we never seen any eggs hatched but those of
birds, which require 104, we should have concluded
that all others require the same. A little initiation
into the study of minute animals teaches how many
kinds produce at a temperature infinitely less. Such
are the eggs of butterflies and many other insects, of
frogs, lizards, tortoises, down to some, as those of
toads, which I have seen produce at 45. If these
eggs hatch at 59 less than is required by those of
birds, what repugnance will there be to suppose that
at 13 less, or the freezing point, the eggs of other
animals may be hatched ? Nor should it surprise me
to be told of animals whose eggs would produce at
much greater cold, after knowing that there are plants,
beings so similar to animals, and many of them,
* In plain language, Spallanzani did not know what to
make of the facts.
9
98 INSECT TRANSFORMATIONS.
which amidst the rigours of winter flourish and fruc-
tify,'*
It is remarked by John Hunter that an egg will
freeze by a great degree of cold; at the same time
there seems to be a living principle which enables it to
support cold without destruction, and when once that
principle is destroyed, cold more easily operates. An
egg was thus frozen by the cold of zero; after thaw-
ing and again exposing it to the same degree of cold,
it froze seven minutes and a half sooner. A new-laid
egg took an hour to freeze in 15 and 17, but when
thawed, it froze at 25 in half the time.|
The principle of vitality, therefore, whatever may be
the cause, is evidently less easily destroyed in the egg
state than in the perfect animal; and therefore the
inference that a rigorous winter promises a diminution
of insects in the summer succeeding commonly proves
erroneous. On the contrary, recorded facts prove
that they are sometimes even more abundant than
usual after severe frosts. During the present spring
of 1830, accordingly, notwithstanding the severe frosts
of the preceding winter, we have observed a much
greater number of insects, even of the smaller and
more delicate kinds (Jlleyrodes, Corethra, Jllucita y
&c,) as well as of larvae, both those just hatched, and
those which have lived through the winter, than last
year, when the frost was not so severe. We were
particularly struck with the larvee of some small
tipula (Boletophila?), which we found in abundance
in Birch Wood, Kent, feeding on a fungus (Boletus
fomentarius, FRIES), and which were so beautifully
transparent and soft, that we could not understand
how they had escaped being frozen. It is not a
little remarkable, in connexion with this, that the
* Spallanzani's Tracts, transl. by Dalyell, vol. i, p. 63.
t Hunter on the Animal Economy.
EFFECTS OF COLD UPON INSECTS. 99
migratory birds seem to have been aware of this abun-
dance of insects by their appearing earlier than usual.
We saw a pair of nightingales at Greenhithe on the
21st of March, and a number of swallows the same
week at Lee, which is two or three weeks before
their average time.*
* J. R.
CHAPTER V.
Hatching of Insect Eggs.
THE contents of an egg principally consist of
nutriment adapted to the different parts of the
germ which it contains the yolk for nourishing
the soft parts; tfce white, for the blood and other
fluids; and the shell, for the bones. In the case of
insects, as well as of birds, fishes, and reptiles, the
embryo is placed in the most advantageous posi-
tion for partaking of the repast, namely, in a par-
ticular corner where it may breathe fresh air always
communicated to the chamber of the egg by ven-
tilatory passages in the shell; if these be shut up,
by covering the egg with grease, varnish, or chalk,
it is suffocated and dies. In the case of birds,
according to Malphigi and the older physiologists,*
the rudiment of the chick, while still a minute point,
is lodged on the film that envelopes the yolk, near the
centre of the egg; and, as the floating wick of a
mariner's lamp is constantly preserved upon a level
with the surface by the mobility of the slings and the
weight of the oil-vessel tending downwards, how-
ever the ship move, there is an ingenious natural
mechanism, which prevents the embryo chick from
being upset when the egg is stirred. The yolk is
sustained by two membranous ribbons, visible at the
aperture of the egg, and fastening it on each side to
the common membrane glued to the shell. These
suspensory bands being fixed above the centre of the
* Malpighi, de Ovo incubato , Leeuwenhoeck, Epist. phys.
xl ; and Harvey, in Willoughby's Ornithol. c. iii.
HATCHING OF EGGS. 101
yolk, of course the mere weighty part always de-
scends, in every position of the egg, as far as they
will permit, and the chick being thence prevented
from sliding down, nourishes itself in security.
We cannot, on account of their minuteness, as Cer-
tain whether there is any similar mechanical contriv-
ance in the eggs of insects ; but we have in several
instances distinctly observed the speck where the em-
bryo insect was placed just within the shell of the
egg. In order to stimulate it to feast and fatten on
the good things stored up in his egg shell chamber,
it appears that a certain degree of heat is indispensa-
bly requisite; for cold, though it does not usually, as
we have seen, kill the embryo, almost always renders
it torpid. But the stimulus of heat produces activity
in the living principle, causes the embryo to devour
all the nutritive contents of the egg, and thence to in-
crease proportionably in size. It is worthy of remark,
however, that the stimulus of light, contrary to that of
heat, acts unfavourably upon the hatching of eggs.
Both of these positions may be illustrated by nume-
rous facts and experiments.
Most birds, so far as has been ascertained, supply
the heat necessary for hatching their eggs by sitting
constantly upon them during a certain number of
days ; but reptiles, such as the crocodile, bury their
eggs in the warm sand upon the banks of rivers.
Insects, again, seldom, if ever, sit upon their eggs, as
birds do, in order to hatch them. This, indeed,
would be impossible, as the greater number of insects
die in a few days after depositing their eggs, the con-
tinuation of the species being apparently their only
business in their last or perfect stage ; since, as they
then generally cease to feedV, they cannot possibly live
long. A few instances, however, have been observ-
ed, of insects performing something very similar to the
9*
102 INSECT TRANSFORMATIONS.
incubation of birds, though we have the high authority
of Fabricius, that < insects never sit upon their eggs. 7 *
Upon the incontestable statements of two distin-
guished observers of insects, Frischf and De Geer,
the female of the common earwig (Forficula auricula-
ria, LINN.) sits upon her eggs. This circumstance,
however, seems to have escaped the notice of other
naturalists, though her attentions to her young ones
is often witnessed. De Geer discovered a female ear-
wig in the beginning of April under some stones, and
brooding over a number of eggs, of whose safety she
appeared to be not a little jealous. In order to study
her proceedings the better, he placed her in a nurse-
box filled with fresh earth, and scattered the eggs in
it at random. She was not long, however 4 , in collect-
ing them with all care into one spot, carrying them
one by one in her mandibles, and placing herself over
them. She never left them for a moment, sitting as
assiduously as a bird does while hatching. In about
five or six weeks the grubs were hatched, and were
then of a whitish colour. J At another time, in the
beginning of June, De Geer found under a stone a
female earwig accompanied with a numerous brood of
young, to all appearance newly hatched, and nestling
under their mother like chickens under alien. These
he likewise placed in a nurse-box with fresh earth ;
but instead of burrowing into the mould, as he had
expected, they crowded under the bosom and between
the legs of their mother, who remained quiet and evi-
dently pleased, suffering them to continue there for
an hour or more at a time. He fed both this brood
and the one first mentioned with bits of ripe apple ;
and perceived that they grew from day to day, and
* Fabricius, Philosoph. EntOmoI. Ixxvi.
f Insecten in Deutschland, 4to, 1766.
t De Geer, Mem., vol. Hi, p. 548.
HATCHING OF EGGS. 103
cast their skins, as caterpillars do, more than once.
The mother did not live long, probably in consequence
of confinement ; and her progeny devoured nearly the
whole of her body, as they also did the bodies of their
brethren, when any of these chanced .to die. We
may remark, in passing, that it is an unfounded popular
prejudice that earwigs get into the brain by creeping
into the ear ; for though, from being night insects,
and disliking exposure to the light, they may, by
chance, attempt to take shelter in the ear, the dis-
agreeable odour of the wax will soon drive them out:
at all events they could never get farther than the
drum, which completely shuts the passage to the brain.
We have known, indeed, a small beetle, get into the
ear; but it did no further injury than produce a
strange tingling sensation by crawling about the
drum, and soon made its exit.* A little red insect
(the harvest bug?) sometimes gets into the ear in
bed, and produces wonderful commotion, but no real
injury.
Drum of the ear, showing that there is no passage through it to
the brain.
Kirby and Spence are inclined to infer that a tree
bug (Jlcanthosotnci grisea, STEPHENS) may also sit
* J. R.
104 INSECT TRANSFORMATIONS.
upon its eggs,* because De Geer found a mother of
this species surrounded with a brood of thirty or forty
young ones following her as chickens follow a hen.
She never leaves her family; but as soon as she
moves, all the young ones closely follow, and assem-
ble around her in a cluster wherever she makes a
halt. De Geer once cut a branch of birch, upon
which a family of these bugs had assembled, and the
mother showed every symptom of fear and distress.
Had she not had a family to protect, she would have
taken immediate flight; but instead of this, she kept
beating her wings rapidly and incessantly, and never
stirred from her young. But even all this, affec-
tionately maternal as it must be considered, is far
from authorizing the conclusion that she sits upon
her eggs ; though it is certain she must remain near
them till they are hatched, unless she belong to those
mentioned by Busch as ovo-viviparous.j"
One of the most common instances of something
similar to birds hatching their eggs occurs in several
species of spiders, which may be seen sitting near
or upon the silken bag in which they have inclosed
their eggs. Many of these mothers, however, die
before their young are hatched, all of them, per-
haps, when the eggs are laid late in autumn. During
the winter of 1829-30, we watched a considerable
number of the geometric spiders (Epeirce) brooding
over their eggs for several weeks; but though the
weather before Christmas was little more than an
average degree of coldness, every one of them died,
some living a longer time, and others a shorter. J But
this is not the case with a very common wandering
spider called by Dr Lister the wolf (Lycosa saccata,
LATR.), and first observed, we believe, by the cele-
brated Harvey.^ ' In order,' says Swammerdam, * to
* Intro, i, 358, and iii, 101.
t Schneider, Europaische Schmetterlinge, i, 206. J. R.
Harvey, De Generatione.
HATCHING OF EGGS. 105
hatch her eggs the better, she carries them about as
it were in a case, with wonderful solicitude and affec-
tion ; insomuch, that when the skin forming this case,
which hangs to the hinder part of her body, is by
any accident broken off, the little insect seeks after
it with as much earnestness and industry as a hen for
her lost chickens, and when found fastens it again
to its place with the greatest marks of joy.'*
Bonnet has given a more detailed account of the
manners of ttys spider, which, though no less fierce
and ferocious in aspect than her congeners, manifests
an extraordinary change of mien when forcibly depriv-
ed of her eggs. Then she instantly appears tame,
stops to look around her, and begins to walk at a slow
pace, and search on every side for what she has lost,
nor will she even fly when one threatens to seize her.
But should the experimenter, moved with compassion,
restore her bag of eggs, she catches it up with all haste,
and darts away in a moment ; or, when left undisturb-
ed, will leisurely attach it again to her body.
' With a view,' continues Bonnet, ' to put this
singular attachment to a novel test, I one day threw
a spider with her eggs into the pit-fall of an ant-lion
(Myrmelion formicariwn) ."\ The spider endeavoured
to escape, and was eagerly remounting the side of the
pit, when I again tumbled her to the bottom, and the
ant-lion, more nimble than the first time, seized the bag
of eggs with its mandibles, and attempted to drag it
under the sand. The spider, on the other hand, made
the most strenuous efforts to keep her hold, and strug-
gled hard to defeat the aim of the concealed depreda-
tor ; but the gum which fastened her bag, not being
calculated to withstand such violence, at length gave
way, and the ant-lion was about to carry off the prize
* Book of Nature, pt i, p. 24.
t See Insect Architecture, p. 209.
106 INSECT TRANSFORMATIONS.
in triumph. The spider, however, instantly regained
it with her mandibles, and redoubled her endeavours
to snatch the bag from her enemy ; but her efforts
were vain, for the ant-lion, being the stronger, suc-
ceeded in dragging it under the sand. The unfortu-
nate mother, now robbed of her eggs, might have at least
saved her own life, as she could easily have escaped
out of the pit-fall ; but, wonderful to tell, she chose
rather to be buried alive along with her eggs. As the
sand concealed from my view what was passing below,
I laid hold of the spider, leaving the bag in the power
of the ant-lion. But the affectionate mother, de-
prived of her bag, would not quit the spot where she
had lost them, though I repeatedly pushed her with a
twig. Life itself seemed to have become a burden
to her since all her hopes and pleasures were gone for
ever.'*
That some portion of heat may be communicated
to the eggs of the spider, which are thus carried so
assiduously under her body, is highly probable ; and
it is also, no doubt, advantageous to the young, when
hatched, to have the assistance of their mother to open
the bag for them, as was remarked by De Geer;|
' without which,' says Kirby and Spence, c they
could never escape. 'J But that neither of these are
indispensable conditions we have ascertained by re-
peated experiments. We have taken a considerable
number of these egg-bags from their mothers, and
put them under inverted wine-glasses and into pill-
boxes, and in every instance the young have been
duly hatched, and made their way without assistance
out of the bag. In all these experiments, the young
spiders joined in concert in making a web across their
prison ; a circumstance at variance with the assertion
* Bonnet, (Euvres, vol. ii, p. 435.
t De Geer, Mem. vol. vii, p. 194.
J Introd. i, p. 361.
HATCHING OF EGGS. 107
copied from Lister into most subsequent works on
natural history, that this species never spins a web.
They might not indeed have done so if they had been
left at liberty.*
A spider of the same species, which Bonnet kept
under an inverted glass, at first was so exceedingly
attached to her bag of eggs, that he could riot beat
her away from it after it was detached. ' By and
by,' he continues, c I observed with surprise that she
had abandoned and kept aloof from the very bag
which she had previously defended with so much cou-
rage and address; and I marvelled still more to see
her run away from it when I placed it near her. I
remarked at the same time that she had become less
agile, seemingly in consequence of sickness. By
more close observation, I discovered that several of
the young ones were hatched, and their numbers
increased by degrees, while all ran towards their
mother and climbed upon her body. Some placed
themselves on her back, some on her head, and some
on her limbs, so that she was literally covered with
them, and appeared to bend under the weight, not so
much from being over-loaded, as from her feeble con-
dition ; and indeed she soon afterwards died. The
young spiders remained in a group upon the body
of their mother, which they did not abandon for some
time, and for the purpose, as I was half inclined
(pardon the odious supposition) to think, of sucking
the juices of her body.'f
In order to prove whether a spider of this species
could distinguish her own egg-bag from that of a
stranger, we interchanged the bags of two individuals,
which we had put under inverted wine-glasses ; but
both manifested great uneasiness, and would not touch
the strange bags. We then introduced one of the
mothers into the glass containing her eggs and the
* J. R. t Bonnet, GEuvres, vol. ii, p. 440.
108 INSECT TRANSFORMATIONS.
other spider; but even then she did not take to them,
which we attributed to the presence of the other, as
all spiders nourish mutual enmity. Upon removing
the stranger, however, she showed the same indiffer-
ence to her eggs as before, and we concluded that,
after having lost sight of them for a short time, she
was no longer able to recognize them.*
A more extraordinary method of hatching eggs oc-
curs in several insects, thence termed ovo-viviparous,
which retain the eggs within their bodies till they are
hatched; and in this way they appear, like larger ani-
mals, to produce young instead of eggs. We do not
here allude to the cochenille insects formerly mention-
ed; for though these cover their eggs with their
bodies, it is after they are laid and imbedded in gos-
samer. Neither can these singular insects be proper-
ly said to sit upon their eggs, inasmuch as the mother
always dies when she has finished laying.
The gufTer (Blennius ovo-mviparus, LACEPEDE),
a British sea-fish, common under stones at low-water
mark, affords an instance of this singular mode of the
eggs being hatched in the body of the mother; and it
is remarkable that when the young are ready to
appear, she leaves her usual haunts on the coast, and
goes farther out to sea, that they may be out of the
reach of their natural enemies. | Our common viper
(Coluber berus, LINN.) is also ovo-viviparous, as are
several other reptiles; though it is an exception to the
general rule in this class. We caught a female of the
nimble lizard (Lacerta agilis, LINN.) on a heath
near Sorn, Ayrshire, in July, and kept it for some time
under a glass, where it produced six young ones; but
in consequence of improper food, or of confinement,
they all soon died.J This lizard is said to be some-
times oviparous. The observations also of the elder
* J, R. t Lacepede, Poissoris, ii, p. 497. $ J. R.
OVO-VIVIPAROUS INSECTS. 109
naturalists with respect to the scorpion's being ovo-
viviparous, have been recently verified by Leon
Duibur,* a living French naturalist, distinguished for
acuteness and accuracy.
In the case of insects, it was first discovered by
Redi, the father of experimental entomology, that,
though the greater number of flies lay eggs, some
also bring forth their young alive; and he was thence
led to put the question, whether such flies, under dif-
ferent circumstances of temperature, do not sometimes
produce young, and at other times deposit eggs."f He
might as well, says R aumur, have asked whether,
in certain circumstances, a hen, instead of laying
eggs, should bring forth chickens. The fact, on the
contrary, has been ascertained by Rf aumur, and re-
cently confirmed by Dufour,J that the ovo- viviparous
insects are furnished with an abdominal pouch, in which
the eggs are deposited by the mother previous to their
being hatched. In this respect they afford a striking
analogy with the kangaroo, the opossum, and other
marsupial quadrupeds, which are furnished with a simi-
lar pouch for protecting their young in the first stage
of their existence. One of our most common flies
exemplifies this.
It may not have occurred to many of our readers
that there are more sorts than one of the large flies
usually called blow-flies and flesh-flies. One of these,
distinguished by its brilliant shining green colour and
black legs (Musca Ccesar, LINN.), we have adverted
to in recounting the experiments of Redi; another,
frequently called the blue-bottle (Musca vomitoria,
LINN.), is easily distinguished by the abdomen being
of a shining blue, the shoulders black, and the forehead
fox-coloured. The insect, however, to which we wish to
call attention at present, though nearly the size of the
* Nouv. Diet. d'Hist. Nat.,xxx, 426.
t Redi, Esperienze intorno alia Gen. degP Insetti, 4to, 1668.
t Annales des Sciences Naturelles. Page 3.
TOL. VI. 10
110 INSECT TRANSFORMATIONS.
blue -bottle, rather longer and more slender, and black,
with lighter stripes on the shoulders, is not blue in the
abdomen, but grayish black, and all over chequered
with squares of a lighter colour. This chequered blow-
fly (Sarcophaga carnaria, MEIGEN) does not even
belong to the same genus as the preceding, and differs
from it in the remarkable circumstance of hatching
its eggs in an abdominal pouch, and instead of eggs
depositing maggots upon dead carcasses. The eggs
of all the flesh flies are in sultry weather hatched with
great rapidity; but in the case of the chequered blow-
fly, nature has provided the means of still more rapid
destruction for removing the offensive parts of carcasses.
The arrangement of the numerous minute Iarva3 in the
pouch is very remarkable, and resembles the coil of a
watch-spring or a roll of ribbon. R aumur had the
patience and perseverance to uncoil this multitudinous
assemblage of flies in embryo, and found it about two
inches and a half in length, though the body of the
mother-fly herself was only about one-third of an inch,
A, the chequered blnw-fly B, the abdomen of the chequered
Mow-fly, opened and magnified, showing the coil of young larva 1 .
C, the coil of larvqp partly unwound.
OVO-VIVIPAROUS INSECTS. 1 1 1
and he computed that there were about 20,000 young
in the coil.* When this extraordinary fecundity is
considered, we need not wonder at the countless swarms
which appear as if by magic upon a joint of meat du-
ring hot weather.
Like most female insects, the mother-fly dies in a
few days after giving birth to her numerous brood;
but, unlike the oviparous flies, she seems to take a
considerable time to deposit the whole. It would be
impossible indeed for her pouch to contain the larvae
if they were all hatched at the same time; and there-
fore it has been so ordered by Providence that they
should arrive at maturity in succession. From the
early death of the mother, R aumur conjectured that
they did not scruple to eat their way through her
bowels; but he disproved his supposition by a most
decisive experiment. He took a fly which had already
deposited a few larvae, and closed the natural opening
of the pouch with sealing-wax, so that it was impossi-
ble any more could make their exit there. The mother
lived several days longer than she would have done,
had she been left at liberty to produce her young; but
not one of them attempted to force a passage, after
being shut up for ten days.
Another large gray fly with brick-red eyes (species
A, large gray blow-fly, with the abdomen opened, showing the young
maggots. B, breathing apparatus of the maggot of a large gray blow-
fly-
* Reaumur, Mem. iv, 417.
112 INSECT TRANSFORMATIONS.
not ascertained) was discovered by Rt'aumur to be ovo-
viviparous; but the embryo flies were not arranged in
the pouch in the same spiral form as the preceding, but
longitudinally. These did not appear to be quite so
numerous; and they had a peculiar breathing appara-
tus, which, when shut, as it could be at pleasure, ap-
peared in the form of a crown.
Amongst several other ovo-viviparous flies discovered
by R aumur, there was a very minute tipulidan gnat
(species not ascertained) with a jet-black body, white
wings, and beaded antemue, not larger than the head
of an ordinary pin, which was bred in great numbers
from some cows' dung put into one of his nurse-boxes
for another purpose. He justly remarks upon this cir-
cumstance, that 'the minute and the grand are nothing,
or rather are the same, to the Author of nature.'
The numerous genus Aphis presents the singular
anomaly of producing eggs in the autumn and living
young during summer, and, as Curtis tells us, even
during winter in green-houses. De Geer, however,
ascertained that it was not the same individual aphides
which at one season produced young and at another
eggs, but different generations.* By a series of very
careful and troublesome experiments Bonnet also ascer-
tained the curious fact, that in three months nine gene-
rations of these insects may be produced in succes-
sion, though the males be rigorously excluded from the
nurse-boxes where the females are isolated. In fact
all the aphides produced in spring from the eggs laid
in autumn appear to be females; and no males are pro-
duced till the end of summer, a short time before the
eggs are deposited for winter. Among both males and
females are some with and some without wings, the
nature of which distinction does not appear to be yet
ascertained.
* De Geer, Mem. des Insectes, iii, 70.
EGGS GF APHIDES. 1 13
Bonnet, however, whose opinion is entitled to
considerable authority, seems to think that the eggs of
aphides which are destined to survive the winter are
very different from other eggs; and he supposes that the
insect, in a state nearly perfect, quits the body of its
mother in that covering which shelters it from the cold
in winter, and that it is not, as other germs are in the
egg, surrounded by food, by means of which it is de-
veloped and supported. It is nothing more, he con-
jectures, than an asylum of which the aphides ap-
pearing at another season have no need; and it is for
this reason that some are produced naked and others
enveloped in a covering. If this be correct, the mo-
thers are not then truly oviparous, even in autumn,
when they deposit these pseudo-eggs; since their young
are almost as perfect as they ever will be, in the asy-
lum in which they are naturally placed at birth. It
was in vain that Bonnet endeavoured to preserve
eggs of this sort in his chamber till spring, in conse-
quc nee, he imagines, of the want of a certain degree
of moisture which they would have had out of doors
We have been more successful, through the precaution
of not taking the eggs from their native tree till Feb-
ruary, and in 1830 we had a brood of several hundreds
produced of the oak aphis (Jlphis Quercus).*
The failure on the part of Bonnet leads us to re-
mark, with the younger Huber, that ants are more
skilful in this respect than naturalists, and anxiously
nurse, during winter, the eggs of aphides, which they
collect with great care in the autumn. The interest-
ing narrative of the discovery of this we shall give in
Huber's own words.
( One day in November,' says he, ' anxious to
know if the yellow ants (Formica flava) began to
bury themselves in their subterranean chambers, I de-
stroyed, with care, one of their habitations, story by
* J.R.
VOL. vi. 10*
114 INSECT TRANSFORMATIONS.
story. I had not advanced far in this attempt, when
I discovered an apartment containing an assemblage
of little eggs, which -were for the most part of the
colour of ebony. Several ants surrounded and ap-
peared to take great care of them, and endeavoured,
as quickly as possible, to convey them from my sight.
I seized upon this chamber, its inhabitants, and the
treasure it contained.
' The ants did not abandon these eggs to make
their escape; a stronger instinct retained them: they
hastened to conceal them under the small d welling
which I held in my hand, and when I reached home,
I drew them from it, to observe them more attentively.
Viewed with a microscope, they appeared nearly of
the form of ants' eggs, but their colour was entirely
different; the greater part were black; others were of
a cloudy yellow. I found them in several ant-hills,
and obtained them of different degrees in shade; they
were not all black and yellow; some were brown, of a
slight and also of a brilliant red and white; others
were of a colour less distinct, as straw colour, grayish,
and I remarked that they were not the same colour at
both extremities.
' To observe them more closely, I placed them in
the corner of a box faced with glass; they were col-
lected in a heap like the eggs of ants; their guardians
seemed to value then! highly ; after having visited them,
they placed one part in the earth, but I witnessed the
attention they bestowed upon the rest ; they approach-
ed them, slightly separating their mandibles; passed
their tongue between each, extended them, then walk-
ed alternately over them, depositing, I believe, a liquid
substance as they proceeded. They appeared to treat
them exactly as if they were eggs of their own
species; they touched them with their antennae, and
frequently carried them in their mouths; they did not
quit these eggs a single instant; they took them
CARE BY ANTS OF EGGS OF APHIDES. 115
up, turned them, and after having surveyed them
with affectionate regard, conveyed them with extreme
tenderness to the little chamber of earth I had placed
at their disposal. They were not, however, the eggs
of ants; we know that these are extremely white, be-
coming transparent as they increase in age, but never
acquire a colour essentially different. I was, for a
long time, unacquainted ^ jth the origin of those of
which I have just spoken, and by chance discovered
they contained little aphides; but it wab not these in-
dividual eggs I saw them quit; it was other eggs
which were a little larger, found in the nests of yellow
ants, and of a particular species. On opening an ant-
hill, 1 discovered several chambers containing a great
number of brown eggs, of which the ants were ex-
tremely jealous, carrying them with the utmost expe-
dition to the bottom of the nest, disputing and con-
tending for them with a zeal which left me no doubt
of the strong attachment with which they regard
them.
* Desirous of conciliating their interests, as well as
my own, I took the ants and their treasure, and placed
them in such a manner that I might easily observe
them. These eggs were never abandoned. The ants
took the same care of them as the former. The fol-
lowing day I saw one of these eggs open, and an
aphis fully formed, having a large trunk, quit it. I
knew it to be a puceron of the oak: the others were
disclosed a few days after, and the greater number in
my presence. They set immediately about sucking
the juice from some branches of the tree I gave them,
and the ants now found, within their reach, a recom-
pense for their care and attention. The.ant-hill whence
these eggs had been taken was situated at the foot of
an oak, which readily accounts for their existence in
that place. I discovered them in the spring; the pu-
cerons which quitted them were very large for insects
116 INSECT TRANSFORMATIONS.
just born, but they had not yet obtained their full
size.'*
It is not, however, the aphides themselves who select
the snug winter retreat of an ant-hill, or who know
how to secure the careful nursing of the ants. All
this is the sole concern of the latter, to secure for them-
selves a supply of the honey-dew, as it is erroneously
called, secreted by the aphides in spring. The ants,
it may be proper to remark, take similar care of their
own eggs (as well as of their cocoons, popularly sup-
posed to be their eggs) as was remarked by Sir 1C.
King, in the reign of Charles II. He informs us that
they diligently gather together in a heap their true
eggs, which are small and white like the granules of
lump sugar, and upon these e<*gs they lie in multi-
tudes, i I suppose,' says Derham, < by way of in-
cubation. 'I * I have observed,' adds Sir E. King,
1 in summer, that in the morning they bring up those
of their young called ant -eggs (cocoons] towards the
top of the bank, so that you may, from ten o'clock till
five or six in the afternoon, find them near the top,
for the most part on the south side. But towards
seven or eight at night, if it be cool, or likely to rain,
you may dig a foot deep before you can find them.'J
An interesting family of two-winged flies (Hip-
poboscidce, LEACH) resemble the aphides in some
points of their economy, though in others they are
singularly peculiar. R aumur discovered, what has
been recently confirmed by Dufour and others, that
the mothers not only hatch their eggs within the body,
but retain them there till they are changed into chry-
salides. R aumur gives a lively narrative of his
discovery, and the solicitude of his servants to find him
female flies ready to deposit what he at first took for
* M. P. Huber on Ants, p. 245.
t Derham, Phys. Theol. ii, 207. llth ed.
t Phil. Trans. No. xxiii.
OVO-VIVIPAROUS FLIES. 117
eggs. He was so anxious to hatch those supposed
eggs that he carried them in his pocket by day and
took them to bed with him at night, (as Bonnet after-
wards did with the eggs of aphides,) for several weeks
successively; but instead of grubs, as he had expected,
perfect flies were evolved exactly similar to their pa-
rents. He calls them spider flies, from their resem-
blance to spiders; and in some parts of France the
species which infests horses (Hippobosca equina) is
called the Spaniard or Breton: in England it is too
well known under the name of the forest fly.
Spider flies (Hippoboscidcp, Leach.)
We have the more willingly introduced this sub-
ject here, that another fly (Crattrina Hirundinis y
OJ.FERS), of the same family, has the instinct to de-
posit its egg-like cocoons in the warm feathery nest of
swallows, where they have all the necessary heat
which R aumur, in his experiments, was so careful to
maintain. In return for the warmth which the young
has thus received, the perfect fly, during its brief ex-
istence, lives by sucking the blood of the swallows, as
the one first mentioned sucks the blood of horses,
horned cattle, and ; it is also said, of man.
118 INSECT TRANSFORMATIONS.
The effect of heat upon the eggs of insects has been
carried much farther than in the experiments just
alluded to of R aumur and Bonnet.* Spallanzani
was desirous of ascertaining what degree of heat the
eggs of insects and other animals, as well as the seeds
of plants, would bear when compared with their larvae;
and he found that below 93 Fahr. silk-worms did
not appear affected, but at 95, and still more at 97 ,
they became restless, while at 99 they ceased to move,
and all died at 108. The eggs of these, on the
other hand, long resisted the influence of heat. At
80 they were the most productive; at 99 many still
appeared, but with considerable diminution, and as
the heat was increased their fertility decreased, till at
144 not one was fertile. The eggs and caterpillars
of the elm butterfly (Vanessa polychlorosl) perfectly
corresponded with those of the silk-worm. In the case
of the eggs of the blow-fly (Musca vomitoina) a great
many produced maggots at 124; but at 135 and
138 very few, and all were sterile at 140. The
maggots produced from these eggs became restless at
88, and endeavoured to escape, and as this heat was
increased they became proportionably more agitated
till it arose to 108, when they all perished. Full-
grown maggots of the same kind all died at 108;
but when changed into flies they died when the heat
was so low as 99; though their pupae were produc-
tive at 104 and 106, but not at lll.t
If these experiments may, as we believe they may,
be relied on, we have some reason to doubt that ' the
eggs of the musca vomiloria, our common blow-fly,
are often,' as Dr Good affirms, ' deposited in the
heat of summer upon putrescent meat, and broiled
with such meat over a gridiron in the form of stakes, in
a heat not merely of 212, but of three or four times
; and yet, instead of being hereby destroyed, we
* See Insect Architecture, p. 24.
t Spallanzani, Tracts by Dalyell, vol. i, p. 85.
EFFECTS OF HEAT UPON EGGS, 119
sometimes find them quickened by this very exposure
into their larva or grub state.'* It would have been
well if some more accurate authority had been given for
so miraculous a fact than this general statement: the
appearance of maggots on broiled meat, from which the
inference is apparently made, seems rather to indicate
that eggs, or more probably ovo-viviparcus larvae, had
been deposited there, not before, but after the broiling.
One certain result of all such experiments is, that
eggs are more capable of withstanding heat than the
animals producing them; and from similar experi-
ments the same law appears to hold with the seeds
of plants, which also withstand more heat than eggs.
Water increases the destructive influence of heat.
The causes upon which these curious facts depend
do not appear to be well understood It is certain,
however, that the life of an animal in the egg is feeble,
or at least lethargic, in comparison with that of the
animal produced; and that animals, when in a state of
very feeble animation, resist external injuries with
more impunity than when very vivacious. We once
saw a very delicate young girl, emaciated with scro-
fula, have her leg amputated without even heaving a
sigh; while a robust Irish labourer, who underwent
the same operation immediately after her, roared like
a bull.
Experiments prove that the fluids of eggs, and con-
sequently of their germs, are more abundant than in
vegetable seeds; and this excess of fluid may tend to
destroy the germ more readily, from heat expanding
the fluids, and thus putting them in motion: for then
they must strike violently against the tender parts of
the germs, arid rupture and destroy them. Hence
seeds exposed to heat are killed at lower degrees in
water, than if dry, in the same way as ice will melt
sooner in warm water than in air of equal temperature. f
* Good's Book of Nature, vol. i, p. 221. 1st edit.
t Spallanzani, Tracts by Dalyell, vol. i, p. 43.
120 INSECT TRANSFORMATIONS.
In the practical management of the eggs of the silk-
worm, Count Dandolo directs the temperature of the
stove-room to be 64 when they are first put in.
c The third day the temperature should be raised to
66; the fourth day to 68; the fifth day to 71; the
sixth day to 73; the seventh day to 75; the eighth
day to 77; the ninth day to 80; the tenth, eleventh,
and twelfth days to 82. When the temperature of
the stove-room is raised to 75, it is advantageous to
have two dishes, in which water may be poured, so as
to offer a surface of nearly four inches diameter. In
four days there will have taken place an evaporation
of nearly twelve ounces of water; the vapour, which
rises very slowly, moderates the dryness which might
occur in the stove-house, particularly during a north-
erly wind: very dry air is not favourable to the devel-
opment of the silk-worm.'* Damp or stagnant air,
or sudden changes of temperature, either high or low,
are exceedingly injurious to the hatching of eggs.
From some very curious experiments of Michelotti,
it appears that exposure to light is by no means favour-
able to the hatching of eggs This ingenious natural-
ist i sclosed a number of eggs in glass vessels, admit-
ting the light to one series and excluding it from
another, similar in every other particular. The result
was, that few or none of the eggs exposed to light
were hatched, while those in the dark were almost all
fertile. He arrived at the same results in his experi-
ments upon vegetable seeds. "f Kirby and Spence
justly remark, that these curious facts may account
for so many insects fastening their eggs to the under
sides of leaves, and may be the final cause of the
opaque horny texture of those exposed in full day.J
Among the singular circumstances in which insects
differ from the larger animals, we may reckon that
* Count Dandolo, on Silk- Worms, Eng. trans., p. 55.
t Philosophical Mag., vol. ix, p. 244. | Introduc. iii, p. 77.
INCREASE IN SIZE OF EGGS.
121
of the eggs of some increasing in size during the pro-
cess of hatching. The fact appears to have first been
noticed by the celebrated Vallisnieri in his observa-
tions on saw-flies (Tenihredinidcz, LEACH).* Other
instances were subsequently discovered by R aumur,
De Geer, Derham, R' sel, and the younger Huber.
' It ought not,' says R aumur, speaking of gall flies
( Cympidce, WEST WOOD), ' to be passed in silence,
that the egg which I found in the gall appeared to
me considerably larger than the eggs of the same spe-
cies when they proceed from the body of the fly, or
even when they are taken from the mother fly near the
time of their being laid. The whole of those I took
front the mother flies which I killed were remarkably
Generation of a water-mite (Hydra-hna alstergens).
a a, the water scojpion, in whose body the mite fixes her eggs.
6 b, a magnified view of one of its claws, c, a tooth-like process for
restraining the motion of the joint. <Z, the water-mite, e, a greatly
magnified view of one of its eggs, y, the hook by which it is inserted
into the body of the scorpion.
* See Insect Architecture, pp. 157-8.
VOL. VI. 11
122 INSECT TRANSFORMATIONS.
small; and I thence inferred that the egg would
have, and indeed had, increased in the gall.'*
R 'sel made a similar observation on the red eggs
of a water-rnite (Hydrackna abstergens) ; and he was
induced to suppose (justly, as we think) that, as they
are deposited upon the bodies of water-scorpions
(Nepidw, LEACH), they derive their means of in-
crease from them.J De Geer remarked that the
water-scorpions, when much infested with them, be-
came gradually weakened as the eggs increased in
size.J
Huber the younger, in the course of his experi
ments, discovered that the eggs of ants, from being
small and opaque, became comparatively large* and
transparent. ' To be convinced of the truth of this,'
he says, ' I viewed those eggs with the microscope.
I also measured them, and having separated them
from each other, found the longest to be those only
in which the grubs were hatched in my presence.
If I removed them from the workers, before they
attained their full length and transparency, they dried
up, and the grubs never quitted them.' Huber is
inclined to attribute this remarkable increase and
transparency to the humidity imparted to them by the
working ants who so assiduously pass them through
their mouths. c For,' he adds, ' if they be not sur-
rounded with a liquid, or preserved from the influence
of the external air, their pellicle, moistened every
instant by the workers, may preserve a certain degree
of suppleness and expansibility, according to the de-
velopment of the included grub.'^
The most minute observations, however, of this
kind, which have hitherto been published^ were made
* R'aumur, Mem. vol. iii, p. 479.
t R sel, Insecten, vol. iii, p. 152.
4" De Geer, Mem. des Insectes, vol. vii, p. 145.
M. P. Huber on Ants, p. 72.
DEVELOPMENT OF EGGS. 123
by Heroldt on the eggs of the garden spider (Epeira
diadcma], to which we formerly alluded. He divides
the process of hatching into twelve periods, according
to the progress of development. This progress is not
measured by time, as has been done in experiment-
ing on the eggs of birds. The germ, or cicatricula,
which is composed of minute granules, when placed
in a due temperature, begins to expand towaids the
extremity of the egg, till it takes the form of a comet,
whose nucleus is the centre of the germ, and whose
tail* consists of transparent globules. On continuing
to expand, or rather to disperse its granules, they
appear to be decomposed into imperceptible mole-
cules, producing a sort of translucent cloud, through
which the globules of the yolk may be distinguished.
The place which the germ previously occupied ap-
pears as a single transparent point. The cloudy
matter next accumulates round the centre of the
germ, assumes a pearly aspect, and becomes solid and
opaque. This is the rudiment of the embryo spider,
the outline of whose head and body becomes appa-
rent, occupying a little more than a fourth of the egg.
At first this embryo appears homcgeneous, but by and
by four little archlets are seen, which are the rudi-
ments of the legs, and at the same time the outlines
of the mandibles are formed. The whole seems to
derive nourishment from the yolk, in which it is rooted
as a parasite plant upon a tree. When the embryo
spider is near its exclusion, it completely fills the inte-
rior of the egg, the shell of which moulds itself close-
ly around the body, and it looks like the nymph of a
beetle.* When sufficiently developed, it makes a rent
in the shell, as was first observed by De Geer, oppo-
site the breast, through which it pushes its head, and
successively disengages its body; but the shell still
envelopes the legs and feet, and it is not without a
* Heroldt, Exercit. de Gener. Aranearum in Ovo.
124
INSECT TRANSFORMATIONS.
great deal of trouble, by alternately stretcbing out and
contracting them, that it succeeds in rending this, and
sets itself at liberty.* Even then the young spider can
neither spin a web nor catch prey; for it is still en-
veloped in an extremely delicate membrane, which it
does not moult unless the weather is favourable and
fine.
Hatching of the egg of the garden spider (Epcira diadema). ' a, natural
size. 6, egg magnified, the ckatricula (a white spot) in the front. C, the
germ enlarged ; u, the head, and 6, the body of the embryo, d, the em-
bryo spider ready to cast off its first skin.
The latter circumstance will enable us to explain
some experiments made by Redi, who kept spiders
newly hatched for many months without food.j In
the experiments made by us upon the eggs of the wolf
spider (Lycosa saccata), we more than once kept the
young in boxes, where they were forgotten and without
food; and we uniformly found that they remained lively
and well so long as they did not cast their embryo
skin; but when they did moult, they could not long
survive the want of sustenance.^
In the eggs of moths, the embryo, previous to ex-
clusion, may be seen through the shell, snugly coiled
* De Geer, Mem. vii, p. 196.
t Diet. Classique d'Hist. Nat. xii, 141.
} Redi, Esperienze, 99. J. R.
CONSTRUCTION OF EGGS.
125
up in a ring, as is distinctly shown in many of the
beautiful and accurate figures of Sepp.*
, egg of the privet hawk-moth fSntn'nx Li^-ustn) magnified,
showing the inclosed embryo, fc, the caterpillar, when grown.
In the case of the eggs of birds, the chick, when
fully developed, breaks the shell with its bill, the
point of which is then furnished with a hard scale.
This is evidently contrived by providential wisdom for
this very purpose, for it drops off in a few days after
the chick is excluded. It is probable that the larvae
of many insects which are furnished with strong man-
dibles gnaw their way through the egg-shell; but we
know that there are others which, like the spider,
rupture their envelope, since the edges appear ragged
and irregular. Others, again, seem to have an open-
ing provided for them, in a door, which only requires
them to push it open. This is the case with the louse
(Pediculus hwnanus}, and with the bird-louse (Nir-
mws), found on the neck feathers of the golden phea-
sant. A still more ingenious contrivance was discov-
ered by the Rev. R. Sheppard^ in the egg of a f eld
bug (Pentaloma, LATR.), which is not only furnish-
voi.. vi.
* Per Wonderen Gods, passim.
11*
126 INSECT TRANSFORMATIONS.
Doors in eggs for the escape, of the larvae.
a, egg of the louse (Ft icu/us humamts). 6, egg of the pentato-
ma. c, shell of a moth's egg found upon the dew-berry, all mag-
nified.
ed with a convex lid, but with a lever of a horny tex-
ture, and in the form of a cross-bow, for opening it,
the handle being fixed to the lower part of the egg by
a membrane, and the bow part to the lid.* On the
leaf of a dew-berry (Rnbus ccesius) we found a beau-
tifully ribbed egg of some moth, which, having been
brought into our study in January, 1830, was hatch-
ed by the warmth, and exhibited an opening similar
to the elastic cocoon of the emperor-moth; each of
the ribs having expanded to allow of the escape of the
caterpillar.
The period at which the eggs of insects are hatch-
ed atter deposition depends mainly upon temperature;
for by keeping them in an ice-house in summer, the
hatching may be retarded, | as it may be hastened
(witness the instance in the preceding paragraph) by
heat in winter; but there are many other circumstan-
ces unknown to us which often hasten or retard the
process. The eggs of the blow-fly (Musca vomito-
ria) are said to hatch within two hours, J while those
of several moths, and numerous other insects, remain
unhatched for six or nine months; perhaps, in some
cases, even for one or more years. It is worthy of
* Kirby an4 Spence, iii, 104. t Reaumur, Mem.
Nouv. Diet. d'Hist. Nat. xii, 564.
PERIODS OF HATCHING. 127
remark, however, that the periods of hatching corre-
spond in a striking manner with the leafing of trees,
and the appearance of other materials fitted for the
food of the young. We observed a good exampla of
this in the spring of 1829. A lackey moth had de-
posited during autumn a spiral ring of her eggs on the
branch of a sweet-briar planted in a garden-pot out
of doors. We removed this into our study during the
winter. Here the warmth caused the tree to bud,
and at the same time hatched the lackeys about a
month sooner than those out of doors. Owing to the
same cause, several colonies of the caterpillars of the
brown-tail moth revived from their torpidity, and came
forth from their winter nests before the. hawthorns
were in leaf, a circumstance which would not have
happened to them out of doors. * Kirby and Spence
give an instance precisely similar, of the eggs of an
aphis found on the birch, and hatched in-doors a full
month before those in the open air.f
It is a remarkable circumstance, long observed by
collectors, that the male broods of insects appear
earlier than the female broods; and it would appear
from the following fact, that there is a similar retarda-
tion in the hatching of female eggs. ' Upon the leaf
of a poplar tree were found three eggs of the puss
moth (Centra mnula),two of which were hatched
about two weeks before the other. The first were
males, the last a female. As they were on the same
leaf, and presumed, therefore, to have been laid by
the same parent, at the same time, the difference of
hatching could not have arisen from difference of wea-
ther, exposure, &c.'J In the case of the lackeys on
the sweet-briar above-mentioned, some were hatch-
ed several days before others, but whether these were
of different sexes we did not ascertain.
* J. R. t Kirby and Spence, Intr. ii, 434.
t J. Rennie, in Mag. of Nat. Hist., vol. i, p. 373.
SECTION II. LARVJE.*
CHAPTER VI.
Structure of Caterpillars, Grubs, and Maggots.
IT is reported by Boerhaave, in his life of Swam-
merdarn, that when the Grand Duke of Tuscany was
visiting the curiosities of Holland, in 1668, he found
nothing more worthy of his admiration than the na-
turalist's account of the structure of caterpillars, for
Swarnmerdam, by the skilful management of instru-
ments of wonderful delicacy and fineness, showed
the prince in 'what manner the future butterfly lies
neatly folded up in the caterpillar, like a flower in
the unexpanded bud. He was, indeed, so struck
with this and other wonders of the insect world, dis-
closed to him by the great naturalist, that he made
him a princely offer to induce him to reside at his
court; but Swarnmerdam, from feelings pf indepen-
dence, modestly declined to accept it, preferring to
continue his delightful studies at home. The facts
which thus struck the Duke with admiration, we shall
now endeavour, with the aid of Swammerdam, to
trace. But, before we proceed, it may not be out of
place to advert to some very novel views which have
* It may be proper to repeat here, that an insect, when
hatched from the, egg, is called by naturalists It rva ; and in
popular language, a caterpillar or grub, if furnished with feet,
and a maggoty worm, or gentle, if without feet.
ANIMAL AND VEGETABLE TRANSMUTATIONS. 129
been recently started by continental naturalists, who
maintain that vegetables are actually converted into
animals, and these again into vegetables.
It must be obvious, we think, from the details we
have already given, that the doctrine of transmuta-
tion, so far as regards insects, is equally absurd and
impossible with the pretended alchemical transmuta-
tion of lead and other inferior metals into gold and
silver; which doctrine was, indeed, supported upon
the supposed fact of insects being thus transmuted.*
But visionary as either of these may appear, they have
both been supported by men of talent and distinguish-
ed reputation. It does not, perhaps, at first sight
seem more impossible, that water should be transmu-
ted into diamonds, or brass into gold, than that an
egg should disclose a chick or a caterpillar, or that a
caterpillar should change into a butterfly or a beetle;
but by adhering rigidly to facts, and rejecting as rigid-
ly all fancies and analogies, how plausible soever they
may appear, we are certain that the latter changes are
of common occurrence, whereas the former are con-
trary to all experience, and to the best experiments.
We say the best; because observations, if not experi-
ments, have been made for the express purpose of
proving such improbable transmutations.
' I have shown to a great number of persons,' says
Professor Agardh, c the changeable crow-silk (Con-
ferva mutabiliS) ROTH; Draparnaldia m. BORY ST
V.) in its state of a plant, the 3d of August, change
by the 5th into molecules endowed with locomobility,
reunite by the 6th into simple articulations, and recon-
stituted by the 10th into the primitive form of the
plant.'! Previous to this (in 1814) Professor Nees
von Esenbeck, of Bonn, published similar observa-
* Sir Theodore May erne, Epist. Dedicat ad Theatrum In-
sect. Mouffetii.
t Agardh, Diss. de Metamorph. Algarum, 1820.
130 INSECT TRANSFORMATIONS.
tions, in which he remarks, that c as the phenomena in
question appear to contradict certain principles admit-
ted into the reigning systems, we often prefer rather
to deny the conclusions of candid and experienced
observers, than to receive what has hitherto been re-
farded as untenable by generally admitted authority
n this situation are placed all observations upon the
transition or metamorphosis of vegetable life (charac-
terised by immobility) into animal lite (characterised
by mobility); the moment when a being, arrived at
the period of its existence, continues itself, as it were,
by a new creation, and the animated embryo develops
itself into a motionless vegetable.'* Agardh, in his
account of another allied family (Ocillatoriaz), has
even given figures, first of the plant, and then of the
animalcules into which its filaments are converted,")*
which induced Bory St Vincent to remark sarcasti-
cally, that 4 all nature appears, to the Professor of
Lund, to be nothing but confervce travestied. 'J
Passing over what has been published on this
strange doctrine by Vaucher, Girod-Chantrans, Tre-
viranus, Cams, and others, we shall only stop to
mention the more recent observations of Francis
Unger. The plant he selected was the Conferva
dilatata ft of Roth. < Within the space of one hour,'
says he, ' I succeeded in tracing, not only the dimi-
nution of vitality and death of the animalcules, but
also the subsequent development of the dead animals
into germinating plants, in such a manner as to
establish the truth of the fact.' He adds with great
simplicity, ' I could scarcely believe ray own eyes.'
Like Agardh, he has given figures of these miracu
* Quoted in ' Annales des Sciences Naturelles' for 1828,
t Agardh, Icones Alg. ined- i, 10.
J Diet. Classique d'Hist. Nat., x, 469.
Annales des Sciences Nat., 1828,
ANIMAL AND VEGETABLE TRANSMUTATIONS. 131
lous changes, which our readers may be curious to
see.
Supposed animal and vegetable metamoiphoses.
Since the only proof of these plants being trans-
muted (as is alleged) into animals, appears to be
their acquiring motion,* and, as linger says,
' swimming freely about;' we think we should be
equally entitled to infer that camphor is animated
because it moves spontaneously when thrown into
water. This property in camphor has not hitherto
been satisfactorily explained; and it would undoubt-
edly be better to leave the phenomena described by
our advocates for transmutation likewise unexplained,
than to leap at once to their startling conclusions..
' We might as well,' says Bory St Vincent,
4 astonish the world with the discovery of a fig-
tree transmuted into a mulberry tree, because the
Broussonetia, when young, has the leaves of the one,
and when old of the other; and by such a system of
observing we shall end in looking upon the oak and
the mistletoe as the same plant: the wand of Circe
could not produce more astounding consequences
* Nees von Esenbeck.
132 INSECT TRANSFORMATIONS.
than the microscope does in the hands of such ob-
servers.'*
It is apparently a branch of the same untenable
theory, which maintains that the fluid termed by
Heroldt the blood of caterpillars is the only original
portion of them, which, being endowed with a forma-
tive power,t produces an envelope for itself of mucous
net-work (rete mucosum), and this again, by means of
a similar power, is successively transmuted into the
caterpillar, the pupa, and the perfect insect ;J in some
similar way, we suppose, to the formative power dis-
played by water, when, during frost, it shoots into
crystals of ice. But the framers of such theories seem
to forget that living blood is a very different thing
from inanimate water, and the growth and nutrition
of animals from the chemical formation of crystals.
Kirby and Spence very justly remark, that Heroldt's
formative power is only an apology for ignorance, and
that his denying the existence. of what he cannot trace,
is no proof of his doctrine, but of his mistake in sup-
posing the first appearance of the organs of the but-
terfly in his microscope to be literally their first
existence. To suppose the blood, we may also re-
mark, endowed with the power of creating insects, gets
rid of no difficulty and explains no phenomenon, while
it is altogether a gratuitous assumption, unproved
and improbable. c Admirable discovery,' exclaims
Virey; ' as if you should affirm that a stone falls
because it falls !' We think it is St Pierre who
remarks, that Nature seldom permits philosophers to
peep to the bottom of her basket ; and we have already
* Diet. Class. d'Hist. Nat. x, 468.
t The German term is c Bildende Kraft,' i. e. Vis forma-
trix, or JVisus formativus.
t Heroldt, quoted by Kirby and Spence, hi, 83.
Quoted by Kirby and Spence.
EMBRYO BUTTERFLIES. 133
recorded many instances, besides the one under con-
sideration, of their strange mistakes in guessing at
what they cannot fathom. We prefer following Swam-
merdam, Reaumur, and Bonnet, in recording what
can be actually seen on examining the structure of
caterpillars.
In a chapter of Swammerdam's Book of Nature,
quaintly headed c An animal in an animal, or the
butterfly hidden in the caterpillar,' we find the fol-
lowing details respecting the caterpillar of the large
cabbage butterfly (Pontia brassicce). The egg of
this insect is of a yellow colour, flask shaped, and
marked with fifteen ribs, converging towards the
smaller end, and extending a little beyond it. The
Egg of the large cabbage butterfly (Pontia brassica), magnified.
caterpillar, but too well known from its ravages, has
sixteen feet, a yellow line along the back, and another
on each side, the rest of the body being bluish gray,
spotted with black; and the whole surface sprinkled
with thin, short, whitish hairs.*
1 In order,' continues Swammerdam, ' to discover
plainly that a butterfly is inclosed and hidden in the
* Ray, Cat, Cantab., quoted by Swammerdam. See fig. a,
page 62.
VOL. VT. 12
134 INSECT TRANSFORMATIONS.
skin of this caterpillar, the following operation must
be used. One must kill a full-grown caterpillar, tie a
thread to its body, and dip it for a minute or two into
boiling water. The outer skin will, after this, easily
separate, because the fluids, between the two skins,
are by this means rarefied and dilated, and therefore
they break and detach both the vessels and the fibres
wherewith they were united together. By this means
the outer skin of the caterpillar, being separated, may
be easily drawn off from the butterfly which is contain-
ed and folded up in it. This done, it is clearly and
distinctly seen, that, within this skin of the caterpillar,
a perfect and real butterfly was hidden, and therefore
the skin of the caterpillar must be considered only as
an outer garment, containing in it parts belonging to
the nature of a butterfly, which have grown under its
defence by slow degrees, in like manner as other sen-
sitive bodies increase by accretion.
f But as these limbs of the butterfly which lie under
the skin of the caterpillar cannot, without great diffi-
culty, be discovered in the full-grown caterpillar, unless
by a person accustomed to such experiments, because
they are then very soft, tender, and small, and are
moreover complicated or folded together, and inclosed
in some membranaceous coverings, it is, therefore,
necessary to defer the operation just now proposed,
until the several parts of the butterfly become some-
what more conspicuous than at first, and are more
increased and swelled under the skin by the force of
the intruded blood and aqueous humour. This is
known to be the case when the caterpillar ceases to eat,
and its skin on each side of the thorax, near under the
head, is then observed to be more and more elevated
by the increasing and swelling limbs, and shows the
appearance of two pairs of prominent tubercles.'*
* Swammerdam, Book of Nature, ii, 26.
EMBRYO BUTTERFLIES.
135
Embryo butterflies (Pontia Brasaicat), as they appear in the
bodies of caterpillars. The wings, antennae, and trunks in the
figures are spread out to show them.
By similar dissections, Malpighi both actually dis-
covered the moth in the body of a silk worm, and also
the eggs of it;* and R'aumur made a similar disco-
very in the caterpillar of the gypsey moth (Uypogymna
dispar).-\
Female of the perlect cabbage butterfly (Pontia brassiccc.)
In order to harden the parts of the incipient butterfly
that are soft, Swammerdam immersed the caterpillar
in a phial filled with equal parts of vinegar and spirit
of wine for sixteen hours, when he found it would
* Malpighi de Bombyce, 29. t Reaumur, Mem. i, 359.
136 INSECT TRANSFORMATIONS.
better bear handling. It may be necessary to remark,
that though all the parts of the butterfly are in this
manner discoverable in the caterpillar, they are only
in the bud, if we may use the expression, and appear to
be out of proportion from being so closely folded up and
unexpanded. The whole, indeed, bears so much ana-
logy to the embryo of a plant in the seed, or the rudi-
, greatly magnified view of a section of the bud of the labur-
num. It exhibits the nascent flowers, arranged in regular order,
previously to their bursting into perfect existence, b. section of
a bean seed, c, seed-leaves, root, and the first true leaf of the
beech.
CONSTRUCTION OF THE CATERPILLAR. 137
ments of a leaf, or of a flower in the bud, that Swam-
merdam has given figures of the parallel developments
of larvae and of a carnation. His selection of this flower
was not perhaps the most happy ; but our readers may
readily obtain examples by carefully dividing the un-
expanded buds of the rose, the lilac, the horse-chestnut,
the American walnut, or beans, and other large seeds
after they have been planted in moist earth, but not
left long enough to shoot into a plant. The preceding
figures will illustrate this better than description. Dr
Grew proved in this manner that flowers which blow
in spring are formed in the preceding year;* and Du
Hamel, on dissecting, in January, the bud of a pear-
tree, found under an envelope of about thirty leaf scales
eight or ten embryo flowers resembling rose-buds be-
studded with hairs. f
The butterfly and the flower-bud, however, differ re-
markably in the manner in which they are nourished,
the latter receiving sap from the enveloping leaf scales,
the former taking food into the stomach through the
mouth of the caterpillar. The stomach, indeed, of the
inclosed butterfly is so capacious, that it fills the greater
portion of its body ; and requires the caterpillar to occu-
py almost its whole time in eating in order to satisfy its
cravings. When the food is digested in the stomach
of the insect, it passes, as in the larger animals, into
the small intestines ;J but it is not, as in them, col-
lected by innumerable little vessels which afterwards
run into one, (as brooks unite to form a river,) and go
to the lungs to be exposed to the air, supplied by
breathing, in order to be there oxygenated and formed
into red blood. Insects, on the contrary, do not
* Grew. Phys. Veg., ii, 60.
t Du Hamel, Physique des Arbres, iii, 1.
$ See * Insect Architecture,' p. 309, D, D.; and this vol.
p. 198.
VOL. VI. 12*
138 INSECT TRANSFORMATIONS.
breathe by the mouth, and are not furnished with
lungs; for though good air is no less essential to their
nutrition and existence, it is brought to act on the di-
gested food in a different manner. In caterpillars, and
in most perfect insects, the air is respired by breath-
ing-tubes usually eighteen in number placed along
the sides,* the mouths of which may be seen moving,
as the air passes in and out, from ten to thirty times
in a minute. When these are covered with oil, or any
other matter preventing the entrance of the air, the
insect, being unable to breathe, is suffocated and dies,
as was observed two thousand years ago by Aristotle. f
The breathing-tubes all run into what may be called a
wind-pipe, one of which lies along each side of the
insect; and these two wind-pipes send off innumerable
small branches with aij; to the vessels containing the
digested food, supplying it with oxygen for the pur-
poses of nourishment. A fluid is thus prepared ana-
logous to the blood of the larger animals, and stored
up in a large dorsal vessel; but this is not at all like
a heart, for though it has been observed to beat, its
motions do not seem to be constant or regular, and
no blood-vessels go off from it. The fluid analogous
to blood may perhaps pass through this singular reser-
voir, as water does through blotting-paper; but as yet
this process has not been accurately investigated. A
more distinct notion, however, of the process of insect
breathing may be obtained from Swammerdam's sketch
of the interior of the water-grub of a May-fly (Ephe-
mera).
It is further conjectured that the portion of the blood
not immediately wanted for nourishing the organs al-
ready formed, goes to form a mass of thickish muci-
lage, contained in floating membranes of a white, yel-
* Insect Archi., p. 303. t Aristotle, Hist. Animal., viii, 27.
WATER GRUB OF A MAY-FLY.
139
Dissection of the water-grub of a May-fly (Ephemera). The back
is laid open, and the nerves, intestines, and respiratory apparatus
exhibited, aaaaaa, six clusters of short tubes, opening on both
sides, through which the creature breathes: the air contained in the
water, passing through these, enters two wind-pipes, bhb b, running
from head to tail, and circulates through every part of the body. The
eight flns, and a portion of the tail bristles have been omitted, to give
the rest of the figure on a larger scale. The central white lines are
the nerves.
140 INSECT TRANSFORMATIONS.
low, or green colour, and apparently analogous to fat
in the larger animals.* This furnishes, as is further
supposed, a store of nutriment for promoting the growth
of the butterfly.!
This brief sketch will serve to give the reader a tole-
rable notion of the internal structure of caterpillars, and
the manner in which their food is elaborated into nutri-
ment; but when we know that Ljonnet wrote a large
quarto volume on the structure of a single caterpillar,
and that Malpighi, Heroldt, Ramdohr, Sprengel, and
Marcel de Serres, are little less voluminous, it will be
understood that we give it merely as a sketch which
we could easily have extended, had it appeared, as it
does not, to be suitable to our plan. It will prove more
interesting, we think, to pass now to the external struc-
ture and appearance.
It will be obvious from what we have said respect-
ing the colours of eggs, that we are not inclined to
adopt in all its extent the theory of many naturalists,
which maintains the peculiar colours and forms of ani-
mals to be given them by nature for the purpose of
concealment from their enemies. As in the instance
of caterpillars this theory meets us again in full force,
we shall mention a few facts which appear not only to
be at variance with it, but show, we think, that the
facts of the theorists may stand as appropriately for
exceptions as for a general rule. Since caterpillars
form the staple food of soft-billed birds and of the
young of most hard-billed birds, not to mention the
parasite grubs of ichneumon-flies which destroy great
numbers, nature has provided an immense abundance
of them, beyond what is requisite for continuing the
race. Were it maintained, therefore, that they were
all by design so formed and coloured as to deceive the
eyes of birds and ichneumons, the purpose of their
* Lyonnet, Anat. de !a Chenille, 106.
"i Reaumur, Mem. i, 145.
COLOURS AND FORMS OF INSECTS. 141
superabundant production would be frustrated. We
have no doubt, indeed, that insectivorous animals can
instinctively detect their prey, in all the usual modes of
concealment, as acutely as the practised eye of a na-
turalist, who can with ease perceive what escapes the
observation of the inexperienced. When a woodpeck-
er is taught by nature to detect a wood- boring cater-
pillar, by the bark sounding hollow when tapped with
his bill, and when an ichneumon fly can detect a chry-
salis closely rolled up in a leaf,* we should be strongly
inclined to doubt that colour or form could afford very
effectual concealment from enemies, though we readily
grant that many probable instances of this have been
adduced. Of these instances it may be well to give
a few examples.
The caterpillar of a nocturnal moth (Noctua algce,
FABR.) is said to assume the colour of the lichens
upon which it feeds, being gray when it feeds on a
gray one (Parmelia saxatilis, ACH.), and always yel-
low when it feeds on a yellow one (Cctraria juni-
perina, ACH.);| the change of colour being (it is
alleged) intended by Providence to conceal it from
its enemies, as it becomes difficult to distinguish it
from the lichens. The caterpillar of the coronet moth
(Jlcronycta Ligustri, OCHSENHEIM.), which feeds
upon the privet, is so exactly of the colour of the un-
derside of the leaf, to which it usually clings during
the day, that a person may have the leaf in his hand
without discovering the caterpillar ;J a circumstance
explained upon the same principle. This, indeed, is
no common circumstance, as many caterpillars
very nearly resemble the colour of the leaves upon
which they feed ; and the wonder rather is, that so
* See { Insect Architecture, 5 p. 174-5.
t Fabr. Vorlesung. in Kirby and Spence, ii, 220.
j: Brahm, Insecten, in ibid, p. 221.
14 INSECT TRANSFORMATIONS.
many others should not be similarly coloured, when
we consider that their stomachs occupy the greater
portion of their bodies, arid are generally gorged with
food. It would be no difficult matter, therefore, to
enumerate several hundred examples of caterpillars
resembling in colour the substances upon which they
feed. It strikes us as more singular to find a great
many which, though they feed on green leaves, re-
semble in colour the gray or brown bark of the
branches where they usually rest when not feeding
Caterpillars of the Clifden nonpareil feeding on the gray poplar.
A marked instance of this occurs in the caterpillar of
one of our largest and most beautiful moths, the Clif-
den nonpareil ( Catocala fraxini, SCHRANK), which
feeds on the ash and the poplar, and is so similar to
a stripe of brown lichen dotted with black, that it
would not be readily discovered by any person but a
naturalist.*
* J. R.
COLOURS AND FORMS OF INSECTS. 143
Caterpillars of the Clifden nonpareil in a more advanced stage of growth.
Of the extraordinary tropical insects popularly
termed Walking-leaves, belonging to several orders
and families (Locusta, Mantis, Phasma, <$rc), the
wing-cases, not only in colour, but in texture, and
even in veining, are so exactly like leaves, from the
fresh green of those newly expanded to the faded
brown of those withered and fallen, that botanists
themselves might be deceived if they were detached
from the insects and exhibited as real leaves. Among
the locusts of Fabricius ( Pterophylla, KIRBY) alone,
we find the various species with wing-cases resembling
in this manner the leaves of the laurel, the myrtle, the
citron, the lily, the sage, the olive, the camellia, thyme,
and grass.
The Spectres (Phasmatce, LICHTENSTEIN), on the
other hand, resemble the smaller branches of trees
with their spray; and so minutely detailed is this mi-
micry that the very snags and knobs, as Kirby and
Spence remark, are accurately imitated. Those who
are curious in such matters may readily find similar
instances in some of our native caterpillars, by no
means uncommon. Tn the latter part of summer, for
example, by beating the bushes of a hawthorn hedge
while an umbrella is held under, the caterpillar of the
brimstone moth (Rumia Cralccgata ? DUPONCHET)
may often be found, appearing, as it stalks along the
144 INSECT TRANSFORMATIONS.
Walking-leaf insect (Phyllia foliata, Dumeril), magnified.
whalebones of the umbrella, like a self-moving withered
branch, the skin being wrinkled and furrowed like the
bark, while the bulgings of the rings and a notched
protuberance on the back add much to the resem-
blance.
COLOURS AND FORMS OF INSECTS.
145
Transformations of the brimstone moth .
c, Ihe caterpillar in its resting position. 6, the m*>h. c, the eggs.
tZ, the young caterpillar.
We found during last summer, on an elder, at Lee,
several specimens of a similar walking-branch cater-
pillar, that of the swallow-tail moth (Ourapteryx
Sambucaria, LEACH), not so common as the preced-
ing, but equally remarkable; for the ringed bulgings
on the body are precisely like those of an elder branch,
while the longitudinal stripes are like the cracks in
the bark.* It is likewise worthy of remark that these
caterpillars, when not feeding, rest upon their pro-
legs, with their body stretched out at various angles
from the branch, their only support being a thread of
VOL. TK
* J. R.
13
146
INSECT TRANSFORMATIONS.
silk, from which the head hangs, in order that they may
always be ready to drop down in safety, by extending
this thread, on the sudden approach of enemies. As
they feed chiefly in the night, they may be seen con-
tinuing in this stiff and singular attitude for a whole
day without moving, < So that, doubtless,' say
Kirby and Spence, ' the sparrows and other birds
are frequently deceived by this manoeuvre, and thus
baulked of their prey. Rh'sePs gardener, mistaking
one of these caterpillars for a dead twig, started back
in great alarm, when upon attempting to break it he
found it was a living animal.'* We are well
Caterpillars of the swallow-tailed moth, resembling the twigs on
which they rest.
* Intr. ii, 236; Rc'sel, Insecten, i, v. 27.
COLOURS AND FORMS OF INSECTS. 147
persuaded, however, that neither a bird, an ichneu-
mon, nor a naturalist, would have been apt to fall into
such a mistake.
This family of caterpillars (Geometridce, STEPHENS)
have been by collectors not inappropriately named
surveyors, loopers, and geometers, from their peculiar
manner of moving, which may readily be conceived
by those who have not seen them, when we mention
that at the commencement of each step their bodies
present a pretty exact figure of the Greek letter tt.
In this position, laying hold with their hinder prolegs,
they stretch out their heads to the full extent of their
body, laying hold with their fore legs while they bring
forward their body into the 1 form again.
Such are among the most prominent examples ad-
duced by naturalists who advocate the theory that
these resemblances to inanimate objects are intended
to conceal insects from their enemies.* We shal/
now give a few instances which have suggested
themselves as no less corroborative of the opposite
doctrine. The first which occurs to us is one of the
surveyor caterpillars, whose movements we have just
been describing, found very commonly on the cur-
rant, the gooseberry, and the black thorn, and called
by collectors the magpie (Jlbraxas Grossulariata,
LEACH.) This caterpillar is very conspicuous from
being spotted, somewhat like the perfect insect, with
black upon a bright yellow ground, and contrasting
strongly both with the deep green of the leaves upon
which it feeds, and the dark-coloured bark upon
which it usually rests. The caterpillars of the water
betony moth (CucuUia Scrophularice, HUBNER),
and of the burnet moth (Euclidia Glyphica, OCH-
SEiNHEiM.), are similarly marked with deep black on a
yellow ground, which must render them very conspi-
cuous. The caterpillars of the small tortoise-shell
* See Kirby and Spence, Intr, ii, 219-237.
148 INSECT TRANSFORMATIONS.
butterfly (Vanessa fTr/icce), are, we admit, very simi-
lar in colour to the nettles they are found on ; but we
cannot, surely, say the same of the dark black ones
of the peacock (V. Jo), also nettle feeders, particu-
larly as these are not only large, but keep together in
numerous companies; which also applies to the cater-
pillar of the Camberwell beauty ( V. Jlnliopa\ as
well as to the conspicuous caterpillar of the buff tip
(Pygcera bucephala, OCHSENH.), so very destructive
in certain years to beeches, oaks, limes, filberts, and
other trees.* Some of those just mentioned, indeed,
are provided, as we shall afterwards see, with better
means of defence than their colours; but if peculiar
colours be given by nature for the purpose of conceal-
ment, as in the instance of the caterpillars of the
small tortoise-shell, why are these studded with thorns
in the same way as the conspicuous caterpillars of the
peacock and the Camberwell beauty ? In this, as
in many other instances, the theory evidently proves
too much.
To the examples which we have here given of
conspicuous caterpillars, we could easily add some
hundreds more; but thinking these sufficient, we
may be permitted, by way of farther illustration, to
allude to the instances remarkable in perfect insects.
Kirby and Spence mention a different kind of imita-
tion of form and colour, which they think f affords a
beautiful instance of the wisdom of Providence in
adapting means to their end.' One of those two-
winged flies (Vblucellce, GEOFFROI), which bear a
considerable resemblance to humble bees, lives during
the larva state in the hives of the latter; and it is
inferred, that as the flies ' strikingly resemble those
bees in shape, clothing, and colour, the Author of
nature has provided that they may enter these nests
* All these caterpillars are figured in this volume: see con-
tents of the engravings.
COLOURS AND FORMS OF INSECTS. 149
and deposit their eggs undiscovered;' for 'did they
venture themselves amongst the humble bees in a less
kindred form, their lives would probably pay the for-
feit of their presumption.'*
A two-winged fly (f'olucella plumat a, Meigen.)
We do not conceive that any dissent from this doc-
trine has a tendency to weaken or destroy the smal-
lest link in the beautiful chain of causes which
leads us upwards to the admirable superintendence
of the great First Cause; and, therefore, we state
that, in the case before us, our justly eminent authors
surely forgot, that bees well know strange individuals
of their own species, and beat them off when they
attempt to plunder their hives; and these robber bees
are not only like but identical with themselves in shape,
clothing, and colour. Indeed, when it is considered
that in the designs of Providence, as evidenced by
the economy of nature, the nourishment of the stron-
ger species of carnivorous animals is as much regard-
ed as the means which the weaker have of escap-
ing from them, such general rules cannot be but of
very limited application.
Darwin, as we formerly mentioned, maintained that
butterflies resembled the colours of the flowers
which they frequent; and many of them may be
* Intr. ii, 223.
VOL. VI. 13*
150 INSECT TRANSFORMATIONS.
granted to do so without leading us to adopt the
inference of the theorists that they are thus coloured
to conceal them from their enemies. Were this, in-
deed, the true cause of these colours, the butterflies
ought to remain stationary on the flowers, without
sporting about in the sunshine, as if on purpose to
show the birds and the dragon flies that they are
living insects, and not inanimate flowers. In the
instance of many moths which fly by twilight, this is
no less obvious; for instead of being of dark dusky
colours, which would have effectually concealed them
from the bats and the fern-owls, they are frequently
white, or at least of such light colours as show well
in the dusk. There is but small need of enumera-
ting examples of this, and it will be sufficient to name
the white-ghost moth (Hepialus Humility, which may
often be seen, where hops or burdocks grow, hovering
on the wing for hours together; the satin moth (Leu-
coma SaliciSy STEPHENS), which floats about the
air like an animated flake of snow-white down, or
flits conspicuously from tree to tree among the higher
branches of a row of poplars; and the magpie moth
(Jlbraxas grossulariata), usually abundant in every
garden, though liberally sprinkled with black spots,
has enough of white to distinguish it in its heavy,
lumbering flight, even when the last rays of the twi-
light are disappearing. That these are not strained
examples of insects so coloured as to be conspicuous
to their enemies, will farther be obvious from a common
contrivance of schoolboys to catch bats. They chalk
the seed-heads of burdocks in such a manner as to
resemble the white moths alluded to; and throwing
these up where a bat is observed fbing, he fails not
to dart upon the supposed moth, and the bur adher-
ing to his wings, brings him down to pay the penalty
of his mistake.*
* J. R.
COLOURS AND FORMS OF INSECTS. 151
If we leave colouring out of consideration, and
look merely at the forms of caterpillars, we think it
must be apparent to the most indifferent observer,
that, though they have often a rather ungainly,
repulsive, and sometimes a formidable aspect, yet
this renders them in numerous instances very conspi-
cuous. The forms, also, we may remark, which ap-
pear disagreeable or threatening to us, may not seem
so to birds and ichneumons which make them their
prey. One of the most singular of these forms of
caterpillars occurs in that of the pebble moth (JVbfo-
donta Ziczac, STEPHENS),* the form being such that
it is not easy for one unacquainted with it to tell which
is the head and which the tail. The puss ( Cerura
Vinula) is another whose form and attitudes cannot
fail to attract the notice of the most indifferent obser-
ver. Dr Shaw, in his Zoological Lectures, quotes
from a country newspaper a most ludicrous account of
this ' monster,' as it is there called, having a head
like a lion, jaws like a shark, a horn like a unicorn,
and two tremendous stings in its tail. The gross ex-
aggeration of this description will be obvious from the
following accurate figures; yet how formidable soever
this caterpillar may appear to us (even Rosel, the
entomologist, was afraid of it at first), we know that
no one is more readily pounced upon by at least two
species of ichneumons, which eem,: therefore, not to
be afraid to deposit their eggs in its body;f and it is
no doubt often made prey of by birds, at least in its
young state; for when full grown, being about as
thick as a man's thumb, it may prove rather too
bulky a morsel. J
Our readers may like to see, by way of contrast
to the exaggerated account quoted by Shaw, the
excellent description of the puss caterpillar given
* Figured in Insect Architecture, p. 172.
f See ibid, pp. 195, and 325-6. J J. R.
152
INSECT TRANSFORMATIONS.
by old Isaac Walton. i The very colours of caterpil-
lars,' says he, ' as one has observed, are elegant and
beautiful. I shall, for a taste of the rest, describe
one of them; which I will, some time the next month,
show you feeding on a willow tree; and you shall
find him punctually to answer this very descrip-
tion: his lips and mouth somewhat yellow; his eyes
Transformations of the puss moth (Centra Vinula). a, the egg.
6-56, young larvse. c, full-grown larva. <i, the pupa, e, the moth.
COLOURS AND FORMS OF INSECTS. 153
black as jet; his forehead purple; his feet and hinder
parts green; his tail two-forked and black; the whole
body stained with a kind of red spots, which run
along the neck and shoulder-blade, not unlike the form
of St Andrew's cross, or the letter X made thus
crosswise, and a white line drawn down his back to
his tail; all which add much beauty to his whole body.
And it is to me observable, that at a fixed age this
caterpillar gives over to eat, and towards winter
comes to be covered over with a strange shell or crust,
called an aurelia;* and so lives a kind of dead life
without eating all the winter. And as others of seve-
ral kinds turn to be several kinds of flies and vermin
the spring following; so this caterpillar then turns to
be a painted butterfly.'')'
Another caterpillar, called by collectors the lobster
(Slauropus Fagi, GERMAR.), which is rarely met
with, has not only very long legs, a circumstance un-
common among caterpillars, but assumes an attitude
similar to the puss just figured, though the shape of
the creature renders it much more strange. This
caterpillar was known to Mouffet, and is indifferently
figured by him, as well as by Albin and Donovan;
Lobster caterpillar (Stauropus Fagi, Germar.)
* See Insect architecture, p. 194.
t Walton's Angler, chap. v.
154 INSECT TRANSFORMATIONS.
but Rosel's figure, which we here copy, is more ac-
curate.
Looking at these very singular forms of caterpil-
lars, we could not anticipate, without previous know-
ledge, that all of them produced insects of nearly the
same shape, though differing considerably in size and
colour. It is not a little remarkable, also, that the
colours of caterpillars, with a few exceptions, such as
the magpie moth (Mraxas grossulariata), are very
different indeed from the insects into which they are
transformed. Plain and inconspicuous caterpillars
will sometimes give splendidly coloured insects, as in
the case of the Vanessa butterflies; while finely mark-
ed caterpillars will give plain insects, as the one whose
gaudy stripes of sky-blue, scarlet, and black, has ob-
tained it the appropriate name of the lackey ( Clisio-
campa neustria, CURTIS), though the moth is of a
dull brownish yellow. Two of our finest native in-
sects, however, the swallow-tailed butterfly and the
emperor-moth, are produced from beautifully coloured
caterpillars; but neither the colours nor the .markings
of these have any resemblance.
A more extraordinary difference, however, between
the first and the last stage of insect life occurs in the
case of those insects whose larvse are aquatic. One
of our commonest families of insects, the gnats (Cw-
licidce, LATR.), whose ingenious mode of construct-
ing a floating raft of eggs we have already described,
affords a very striking illustration of our position.
When these eggs are hatched, the grubs appear; but
they do not, as is said by older naturalists, < make
themselves little lodgments of glue, which they fasten
to some solid body at the very bottom of the water,
unless they meet with chalk, whose softness permits
them to burrow into its substance.'* On the contra-
* Spectacle de la Nature, i, 123.
ORGANS FOR BREATHING IN WATER-GRUBS. 155
ry, they usually swim near the surface of the water, with
their heads downwards and their tails in the air, for a
purpose which will presently be obvious. These grubs,
called scurrs in the north, may be met with in abun-
dance during the summer in ditches or in water-
butts,* appearing like minute, whitish semi-transpa-
rent shrimps or fishes, when their bodies are a little
bent, as they frequently are.
Aquatic grubs of gnats in a glass vessel of water.
The organs for breathing, which are very remark-
able in the grub of the gnat, are not situated along
the sides, as in caterpillars, but in the tail. A tube
for the purpose of respiration goes off from the termi-
nal ring of the body at an angle. Its main buoys,
also, are its tail and its breathing-tube, both of which
end in a sort of funnel, composed of hairs, in form of
a star, anointed with oil, so as to repel water. Swam-
merdam remarks that when, by handling it too rough-
ly, this oil is removed, the grub * can no longer sus-
pend itself on the surface of the water; I have, on these
occasions, observed it put its tail in its mouth, and
afterwards draw it back, as a water-fowl will draw
its feathers through its bill to prepare them for resist-
* See Insect Architecture, p. 20, bottom figure, on the right-
156
INSECT TRANSFORMATIONS.
ing water. '* The air, which enters through several
openings in the breathing-tube, passes onwards to two
lateral wind-pipes, very similar to those of caterpil-
lars, as above described. When it wishes to descend
to the bottom of the water, it folds up the hairs of the
funnel, but by means of its oil retains at their ends a
globule of air; and when it wishes to re- ascend, it has
only to open its hair funnel again.
Larva of the common gnat (Culcx Viflitns?) floating in water,
greatly magnified, a a, the body and head of the larva. 6, the
respiratory apparatus, situated in the tail, c, the larva not mag-
nified,
A similar but more elegant apparatus for the same
purpose occurs in the water-grub of a two-winged fly,
which Goedart called the chamelion fly ( Straiiomys
chamczleon, MEIGEN), because he found it could
live nine months without food. The terminal ring of
this grub is extended to a considerable length, and
fringed at the end with a beautiful star like funnel of
thirty feathered hairs. Whether the creature oils these,
* Biblia, Naturae, i, 154.
ORGANS FOR BREATHING IN WATER-GRUBS. 157
like the grub of the gnat, we know not, hut they
perfectly repel water ; and at the point where the
insect hangs suspended, a small dimple may be ob-
served on the surface. When it wishes to dive to the
bottom, it has the power of bringing the ends of the
hairs together, without diminishing the capacity of the
funnel below ; and a globule of air, for the purpose of
breathing under water, is thus enclosed and carried
down, appearing, as Swammerdam says, like a bril-
liant pearl or polished silver. c As for my part,' he
adds, < I dare boldly affirm, that, the incomprehensible
greatness of the Deity manifests itself in these mys-
terious operations in a particular manner, and affords
us an opportunity of examining, as it were, with our
senses, the divine nature.'*
Buoy like structure in the tail of a water-grub of a two-winged fiy.
'
VOL. VI.
Swammerdam, part ii, 51.
14
158 INSECT TRANSFORMATIONS.
The preceding grub may occasionally be found in
shallow ditches, and about the edges of ponds, in
summer; but a remarkable larva, with a very dif-
ferent apparatus for breathing, is much more common
in similar situations, and also in the open drains from
dunghills, &c. The latter is the maggot of a two-
w,inged, bee-like fly (Helophilus pendulus, MEIGEN),
and from its shape is appropriately termed rat-tailed
by Reaumur. The tail is the part of the grub which
most merits attention, being formed somewhat after the
telescopic model of the ovipositor of the breeze flies,*
a b c
Telescopic-tailed water larvae, n, a glass vessel of water containing
the larvae, natural size, i, magnified view of the tail, with the breath-
ing tube partially contracted, c, a still more enlarged view of the tail.
* See Insect Architecture, p. 403.
ORGANS FOR BREATHING IN WATER-GRUBS. 159
but consisting only of two tubes, the outer one serv-
ing as a sheath, within which the inner one can be
retracted at pleasure. Both of these are composed of
fibrous rings; and are so very extensile, that R aumur
has seen them pushed out to twelve times the length
of the body of the maggot. The contrivance by which
the inner tube is pushed out is no less simple than
ingenious. It is furnished at the base with two
flexible pipes, coiled up, when it is sheathed, into
several folds, and communicating with the double
wind-pipe ( Trachea} in the body. When it wishes
to extend this breathing-tube, therefore, it inflates, by
means of air from the wind-pipe, the flexible pipes,
and in this way pushes them outward, and with them
the breathing-tube, to the extent required. The
breathing-tube itself is very slender, but terminates
similarly to those of the grub of the chameleon fly, in
five bristles. This breathing apparatus is admirably
adapted to the economy of these maggots ; as from
their seeking their food amongst ooze and mud, they
would often be exposed to suffocation, which their
extensile tube effectually prevents.
Water worms (Nais). a a a, half-concealed in the sand.
bbb, their sand-tubes exposed.
160 INSECT TRANSFORMATIONS.
It may not be improper to guard our younger read-
ers against mistaking for these telescopic-tailed larvae,
an animal, found in the same situations, which has a
considerable general resemblance to them, though
it is not even an insect, but a water-worm (JV</is), up-
on which Bonnet made numerous curious experiments.
The nais may be easily known by its being reddish,
while the maggot is of a dirty white colour.
It appears to be the nais, or some similar fresh-wa-
ter worm, which medical men, unacquainted with na-
tural history, have supposed to get into the human
stomach through the medium of water, as we shall
presently notice.
A no less singular structure for respiration than that
just described, occurs in the aquatic larvae of the
dragon-flies Libellulidce, LEACH), which differs so
remarkably from the perfect insects in the beauty of
colour and elegance of form that has procured for
them the gallant appellation of damsels (demoiselles)
in France. This title agrees as badly with their
habits as the popular English name of horse-simmers ^
since they have no apparatus for stinging ; * and so
far,' says R >aumur, ' from seeking an innocent nutri-
ment in the pulp of fruits, or the nectar of flowers,
they are more like amazons than damsels, hovering
in the air only to pounce upon other insects, which
they crush with their powerful mandibles. Should
they quit the margin of a pond or the banks of a
rivulet, where they may be seen hawking about in
multitudes, it is only to pursue and seize the moth or
the butterfly, that has fled for shelter to the bushes.'
Though these larvae are furnished with six feet,
they not only move very little, but do not use them
for walking so much as for capturing their prey.
Their motion is effected by a very peculiar method.
When one of these larvae is procured from the bottom
of a pond or the pool of a brook, let it be put into a large
STRUCTURE OF LARVAE. 161
saucer with water, with some of the dead leaves or sticks
it previously employed as a covering; these will soon
be seen floating towards the tail, and afterwards re-
pelled, as a floating feather will be by a stick of sealing-
wax, or a bit of amber, when electrically excited. When
the insect has been kept out of the water for a short
t'me, the desire, or necessity, of respiration is increas-
ed, and when again put into the water, the pumping
is repeated with unusual force and frequency. If it be
held in the hand, head downwards, and some drops
of water be let fall on its tail, it instantly sucks it in,
and the dimensions of its body become visibly aug-
mented; but it collapses again when the water is ex-
pelled, which is effected by the same apparatus.
While in the water, if a solution of cochineal, saf-
fron, indigo, or any other coloured fluid, be let down,
with great care, by means of a glass tube, just over
the tail of the insect, it will soon be seen to eject a
stream of the coloured solution to the distance of
several inches. Or the same may be seen by remov-
ing it suddenly out of a coloured fluid into limpid
water; when the coloured jet stream will be still more
conspicuous. The most extraordinary circumstance
respecting this jet is, that it propels the creature
through the water in consequence of its being resisted
by the stationary mass of the fluid behind it, and a
contrary current being thence produced by this singu-
lar pumping. As the insect, between every stroke of
the internal piston, is obliged to draw in a fresh sup-
ply of water, #n interval consequently occurs between
the strokes, during which it will sometimes elevate its
tail above water and squirt out a small stream like
that from a little syringe.
This wonderful apparatus serves several purposes;
for, besides aiding the insect to move, the reverberatory
current brings small water insects within its reach:
it is also it would appear, partly appropriated to
VOL. vi. 14*
162
INSECT TRANSFORMATIONS.
respiration, like the gills of fish, though there are
several other spiracles in other parts of the body com-
municating with the large convoluted windpipes.
The anal apparatus is surrounded with five hard,
moveable, triangular pieces, all fringed with hairs,
which it can open or shut at pleasure. The largest
of these pieces is placed above, while the two smallest
stand at the sides, and two of the middle size below.
When they are shut close they form a blunt cone.*
a, grub of a dragon fly; b b, the lody laid open and magnified
to show the windpipes; c, the pumping apparatus shut; d. the
same open; e, head of the insect.
It may not be out of place to take notice here of
another singular structure in the same species of lar-
vae, which is probably unmatched in the insect world.
In the larvae of most insects, the under-lip is small
and inconspicuous, but in those of the dragon-flies,
* De Geer, ii, 666, and Reaumur, vi, 393, &c.
STRUCTURE OF LARVJE. 163
( it is,' to follow the excellent description of Kirby
and Spence, ' by far the largest organ of the mouth,
which, when closed, it entirely conceals, and it not
only retains but actually seizes the animal's prey, by
means of a very singular pair of jaws with which it is
furnished. Conceive your under-lip (to have recourse,
like R aumur on another occasion, to such a compa-
rison) to be horny instead of fleshy, and to be elon-
gated perpendicularly downwards, so as to wrap over
your chin, and extend to its bottom, that this elon-
gation is there expanded into a triangular convex plate,
attached to it by a joint, so as to bend upwards
again and fold over the face as high as the nose, con-
cealing not only the chin and the first-mentioned
elongation, but the mouth and part of the cheeks:
conceive, moreover, that to the end of this last-men-
tioned plate are fixed two other convex ones, so broad
as to cover the whole nose and temples, that these
can open at pleasure transversely like a pair of jaws,
so as to expose the nose and mouth, and that their
inner edges where they meet are cut into numerous
sharp teeth, or spines, or armed with one or more long
sharp claws; you will then have as accurate an
idea as my powers of description can give of the
strange conformation of the under-lip in the larvae of
Liibellulina, which conceals the mouth and face pre-
cisely as I have supposed a similar construction of
your lip would do yours. You will, probably, admit
that your own visage would present an appearance
not very engaging while concealed by such a mask;
but it would strike still more awe into the spectators,
were they to see you first open the two upper jaw
plates, which would project from each temple like the
blinders of a horse; and next, having, by means of
the joint at your chin, let down the whole apparatus
and uncovered your face, employ them in seizing any
164
INSECT TRANSFORMATIONS.
food that presented itself, and conveying it to your
mouth. Yet this procedure is that adopted by the
larvae of the dragon-fly provided with this strange
organ. While it is at rest, it applies close to and
covers the face. When the insects would make use
of it, they unfold it like an arm, catch the prey at
which they aim by means of the mandibuliform plates,
and then partly refold it so as to hold the prey to the
mouth in a convenient position for the operation of the
two pairs of jaws with which they are provided. Rtau-
mur once found one of them thus holding and de-
vouring a large tadpole; a sufficient proof that Swam-
merdarn was greatly deceived in imagining earth to be
the food of animals so tremendously armed and fitted
for carnivorous purposes. In the larvae of Libellula,
FABR., it is so exactly resembling a mask, that if en-
tomologists ever went to masquerades, they could not
more effectually relieve the insipidity of such amuse-
The mask of the dragon-fly grub, in four different states of
opening and shutting.
ments and attract the attention of the demoiselles than
by appearing at the supper table with a mask of this
construction, and serving themselves by its assistance.
It would be difficult, to be sure, by mechanism, to
STRUCTURE OP LARVJE. 165
supply the place of the muscles with which in the in-
sect it is amply provided; but Merlin, or his suc-
cessor, has surmounted greater obstacles.'*
The larvee of the dragon-fly do not, however,
trust to this mask alone for surprising their prey, but
steal upon it, as De Geer observes, as a cat does
upon a bird, very slowly, and as if they counted their
steps; and then, by suddenly unmasking, seize it by
surprise: so artful are they that insects, and even
small fishes, find it difficult to elude their attacks. f
The larva of a very singular insect (Reduvius per-
sonatus, FABR.), which preys upon the bed bug
(Cimex lectularius), not being furnished with a mask,
is at the pains to construct one, composed of dust,
particles of sand, fragments of wool or silk, and simi-
lar matter, which makes it assume so very grotesque a
figure, that the animal would at first be taken for one
of the ugliest spiders. Its awkward motions add not
a little to the effect of its odd appearance. It can, in-
deed, if it so chooses, move with considerable speed;
but for the purposes of successful hunting, it endea-
vours to assume the aspect of an inanimate substance,
and hitches along in the most leisurely manner possi-
ble. It only moves one leg at a time, and having set
one foot forward, it pauses a little before it brings up
the contiguous one, proceeding in the same way with
its other legs. It is no less carefully cautious in
moving its antennae, striking, as it were, first with
one, and then, after a short pause, with the other.
By means of a camel's hair pencil, or a feather, it is
easy to unmask the insect, for, when touched, it usu-
ally abandons its covering.
* Introd. to Ent. iii, 1?6. 1 De Geer, ii, 674,
CHAPTER VII.
Growth, Moulting, Strength, Defence, and Hybernation of Larvae.
FROM the facts being commonly known, we are not
surprised, that an ostrich, nine feet high and 150 Ibs
weight, should be produced from an egg about the
size of a cocoa-nut, or that { a grain of mustard-seed
the least of all seeds when it is grown,' should
become < a tree (Phytolacca dioicaT), so that the
birds of the air come and lodge in the branches
thereof.'* But when similar facts are recorded by
naturalists respecting insects, general readers are apt
to wonder, because they are less familiar with these
details, than with the economy of trees springing from
seeds and birds being produced from eggs. When we
repeat, after Lyonnet, that the caterpillar of the goat-
moth (Cossus ligniperda, FABR.) becomes 72,000
times heavier than when newly hatched,")" we do not
state anything more striking and admirable than that
an embryo of small dimensions should become an ele-
phant, or that an acorn should produce a lofty and
magnificent oak. The facts respecting the growth of
insects have an adventitious interest, because, in con-
sequence of the minuteness of the objects to which
they relate, they are less familiar to popular observa-
tion. In the instance of the silk-worm, the progress
of growth has been accurately ascertained by scientific
cultivators. It appears that a single caterpillar,
weighing when first hatched only the hundredth part
of a grain, consumes in thirty days above an ounce of
leaves, that is to say, it devours in vegetable sub-
* See Irby and Mangle's Travels, letter v.
t Traite Anat. de la Chenille, p. 11,
GROWTH OF SILK-WORMS. 167
stance about 60,000 times its primitive weight. In
warmer climates, silk-worms consume a rather less
quantity of leaves, because these are perhaps more
nutritive; but, in that case, the silk produced is not
so delicate and fine. The following statements are
the result of experiments made by Count Dandolo:
Progressive increase of silk-worms in weight.
GRAINS
A hundred worms just hatched weigh about 1
After the first moulting 15
After the second moulting 94
After the third moulting 400
After the fourth moulting 1628
On attaining their greatest size and weight 9500
They have, therefore, in thirty days increased 9500
times their primitive weight.
Progressive increase of silk-worms in length.
LINES.
A silk-worm just hatched measures about 1
After the first moulting 4
After the second moulting 6
After the third moulting 12
After the fourth moulting 20
After the fifth moulting it may reach 40
The length of the silk-worm, therefore, increases
about forty times in twenty-eight days.*
.By recalling to memory the comparisons of the
eggs of insects with the seeds of plants, and of cater-
pillars with buds, which ought to be taken (if we
may trust Swammerdam) literally rather than poeti-
cally > we shall arrive at more distinct notions of
the manner in which the growth and changes of
larvae are accomplished. The buds of plants are
composed of successive leaves closely embosomed
within each other's foldings, the outer one being
generally hard and corneous, from the exposure of
its vessels to the colds of winter, while the inner
* Count Dandolo on Silk-worms, p. 326, Eng. Trans.
168 INSECT TRANSFORMATIONS.
leaves, being thence protected, remain soft and pulpy,
But as soon as the inner leaves receive an accession
of sap, which rises from the roots on the return of
spring, their vessels swell and their nervures expand;
while the outer leaf, from its vessels being shrunk and
partly obliterated, undergoes little change besides
being pushed out and sometimes entirely thrown off
by the growth of the inner leaves, which it had pre-
viously enclosed. It may be remarked, also, that this
outer envelope of a bud is not united witb the inner
leaves by any interlacing of their substance or of
their vessels, though in some cases there is an adhe-
sive gluten which partly binds them together; but this
is never so strong as to prevent the expansion of the
leaves. On comparing one of the bud envelopes thus
thrown off, we can scarcely persuade ourselves that
so small a covering could ever have contained the
large spreading leaves which have burst from them.
A caterpillar corresponds in several circumstances
with the leaf bud. The outer skin encloses a suc-
cession of several other skins each becoming more
delicate, soft, and indistinct than the one exterior to
it, but gradually, like the expanding leaves, growing
more substantial and firm as it receives a supply of
nutriment. The chief mechanical difference be-
tween the leaves folded up in the bud and the suc-
cessive caterpillars enveloped within the skin of one
newly hatched, is that the leaves in the bud receive
all their nourishment through their foot- stalks from
the root of the tree, whereas the caterpillar is nour-
ished from within by the food digested in its stomach.
The superfluous nourishment, usually in considerable
quantity, and called the fat of the caterpillar, appears
to lie between the successive skins, in a similar way
to the adhesive gluten in the leaf bud. But as the
first inner skin expands and increases in consistence.
MOULTING OF CATERPILLARS. 169
the fat which lies between it and the outer skin
seems to be absorbed into the bod t of the cater-
pillar, and of course swelling it out; while its abstrac-
tion from the interior of the outer skin renders this
much more dry, separates it from the inner skin, and
disposes it to harden and shrivel.
The absorption of the fat also produces the re-
markable consequence of gorging all the channels of
nutrition, so that there is no longer any demand
upon the stomach for fresh supplies of food; and
hunger (which we imagine is caused either by the
want of the accustomed pressure of food on the
terminal nerves in the stomach, or of the irritation of
the absorbents when they are left empty) is no
longer felt. The caterpillar accordingly ceases to
eat, and having no incentive to action remains motion-
less. The outer skin, in the meanwhile, being
deprived of its internal moisture by the absorption of
the fat, goes on to harden and shrink, while all the
internal organs become enlarged by the nutritive fat.
The expansion, therefore, of the body of the cater-
pillar on the one hand, and the shrinking of the old
skin on the other, produce a mutual struggle, which,
from the continued operation of the causes, must, it
is obvious, be soon brought to a termination.
The skin, from losing its internal moisture, loses
also a portion of its colour, and becomes obscure
and dull; and the caterpillar, from being girt and
squeezed by its pressure, begins to turn and twist
itself in various directions, to rid itself if possible of
the inconvenience. By continuing these movements,
the creature succeeds at length in rending the old
skin at its weakest part, which is usually on the
back, just behind the head; and in a few minutes,
using its body as a wedge, it may be seen issuing
through the breach.* The old skin is thus abandoned
* Reaumur, Mem. i, 135.
VOL. vi. 15
170 INSECT TRANSFORMATIONS.
like a worn shirt; and the caterpillar appears in an
entire new dress, the tints of which are fresher and
brighter, and the colours and markings often con-
siderably different from the former. The insect,
also, in consequence of the quantity of fat which has
gone to augment its several parts, becomes all at
once so much enlarged in size, that we can with diffi-
culty conceive how it could have been contained in
the old skin, out of which it has just crept. The
cast skin is frequently so very perfect that it might
almost be supposed to be the caterpillar itself, particu-
larly in those which are hairy, as this contributes to
conceal the shrivelling.
That the above account of the process of casting the
skin is correct, appears both from the careful dissections
which have been made by Swammerdam, Lyonnet,
and Ramdohr, and also from the diseases incident
to caterpillars from deficiency of food or of pure air.
It is a circumstance of common occurrence to those
who are in the habit of breeding insects, that when
they are not supplied with a sufficient quantity of
food, their bodies do not increase enough in thick-
ness to rupture the old skin; yet this becomes in due
time hard and shrivelled from the absorption of the
fat, though the insect, from its inability to break
through, remains imprisoned. It might be sup-
posed, that if plenty of food were at this moment
supplied, it would subsequently acquire sufficient bulk
and strength to rupture and escape from the old skin;
but this is impossible, as we have repeatedly found
to our great disappointment. In the instance of
the caterpillar of the moth, called by collectors the
glory f Kent (Endromis versicolora, STEPHENS),
which we found on a lime-tree at Lee, and were
anxious to rear, fresh food was neglected to be
given to it a short time before its third moult; and
from that time it refused to eat, and soon died. By
MOULTING OF CATERPILLARS. 171
minute examination we found that it was impossible
for it to eat, as all its organs were in a state of
forward preparation for throwing off their exterior
coat, the old skin, in fact, covering them as a glove
does the hand, ard the new head lying distinctly
farther back than the old. Neither the old man-
dibles therefore, which were become dry and stiff,
nor the new ones, which were encased in these,
could bite the leaves; and even if this had been
accomplished, the entrance to the gullet was ob-
structed by the shrivelling of the old skin there,
and deglutition could not have taken place. The
poor caterpillar was in consequence starved to death
in the midst of abundance of food, which it could
neither chew nor swallow. Had it been skilfully
assisted (as it was not) to get rid of the encum-
brance of its old skin, we doubt not that it might
ultimately have recovered.* Reaumur mentions the
very singular circumstance of a caterpillar of the
six-spot burnet moth (Jlnthrocera Filipendulce,
STEPHENS) having actually, before its last moult, bit
off portions of its old skin, which it. first raised up
and afterwards detached and tossed away. He did
not, however, ascertain whether this was an
accidental manoeuvre, or the usual process of this
species of caterpillar ;| though the first, we think, is
the more probable.
The disorder called the Reds by the breeders of
silk-worms, shows itself in red-coloured stains and
blotches upon the skin; while the caterpillars seem
cramped, stupified, and suffocated, their rings dry up,
and they look exactly like mummies. Count Dando-
lo refers this and most other diseases of silk- worms to
chemical agency. The great quantity of vegetable
food devoured by caterpillars must be liable, during
hot weather to fermentation, if it be not digested
* J. R. t Reaumur, Mem. ii, 75,
172 INSECT TRANSFORMATIONS.
soon after it is swallowed, a process which often
terminates in the production of an acid ; and as
acids have a tendency to redden vegetable colours,
the red hlotches are plausibly ascribed to that
cause. This conjecture, which originated with
Count Dandolo, has been proved to be the fact by
Professor Brugnatelli; who made the very unexpect-
ed discovery that the red matter contains uric acid
combined with ammonia, and consequently that the
disorder is similar in its proximate cause to what is
called the red gravel (Lilhia renalis r GOOD) in
man. This acid, then, from its excess in diseased
caterpillars, impedes the process of nutrition, and
prevents the animal from acquiring sufficient strength
to throw off the old skin when the time for this ar-
rives.
It appears, also, from the experiments of Count
Dandolo, that though caterpillars can live longer in
air deprived of oxygen, or otherwise contaminated,
than warm-blooded animals, yet they do not thrive,
and are very liable to diseases, when they have not
access to fresh air. In other words, the food which
has been digested cannot without oxygen be con-
verted into the fluid analogous to blood; and in such
cases, as we have repeatedly witnessed, instead of
being appropriated to nourishment, it is thrown into
the intestines, producing diarrhosa, or scour, as it is
termed by the cultivators of the silk-worm. In this
case the inner skin never acquires sufficient consist-
ence, nor can the old one ever become dry enough to
be cast.
One of the most singular circumstances respecting
the moult of caterpillars, is the manner in which the
hairs are disposed in the new skin before moulting.
These are not> like the feet and other organs, sheath-
ed in the hairs of the old skin, but smoothly folded
down in separate tufts; and if the old skin be
MOULTING OF CATERPILLARS.
173
removed a short" time before it would be naturally cast,
these tufts may be seen in a moist state very similar to
small wetted camePs-hair pencils lying close to the in-
pillar of the sycamore
VOL. VI.
174 INSECT TRANSFORMATIONS.
ner skin, those on the fore part of the body laid to-
wards the head, and from the fourth ring backwards in
a contrary direction.
Swarnmerdarn, R aumur, and other naturalists, re-
peatedly tried the experiment of cutting off the hair
from caterpillars about to moult, without in the least
affecting the hairs on the new skin; bi>t when a foot
or any other member is accidentally multilated, it is
also wanting in the moulted caterpillar, facts which
strongly corroborate the details we have given above.
It is a still more singular circumstance, ascertained
by Svvarnmerdam, De Geer, Lyonnet, and Bonnet, that
caterpillars and grubs not only cast their exte nal skins,
but also that which lines their breathing-tubes and in-
testines. ' Some days,' says Bonnet, ( before the
change, the caterpillar voids along with its excrements
the membrane which invests the interior of its stomach
and intestines. I have also remarked, that during the
moult, packets of the tracheal vessels may be seen
attached to the cast skin, and thrown off along with it.'
De Geer has distinctly seen white fibres proceeding
from the interior spiracles of a butterfly remain at-
tached to the pupa-case. He conjectures that these
fibres consist of the delicate membrane which lines the
wind-pipes; and that they are moulted like the lining
of the stomach of a lobster, or of a caterpillar. Ly-
onnet, in some measure, confirms this conjecture.*
In his admirable description of the rhinoceros-beetle
(Orycles nasicornis^ Swammerdam says of the grub:
Nothing in all nature is, in my opinion, a more won-
derful sight, than the change of skin in these and other
the like grubs. This matter, therefore, deserves the
greatest consideration, and is worthy to be called a
specimen of Nature's miracles. For it is not the ex-
* Bonnet, CEuvres, vol. viii, pp. 303-311.
MOULTING OF GRUBS.
175
ternal skin only that these grubs cast, like serpents;
but the throat and a part of the stomach, and even the
inward surface of the great gut, change their skin at
the same time. Yet this is not the whole of these won-
ders; for at the same time some hundreds of breath-
ing-pipes within the body of the grub cast also each its
delicate and tender skin. These several skins are
afterwards collected into eighteen thicker, and, as it
were, compounded ropes, nine on each side of the
body, which, when the skin is cast, slip gently and
by degrees from within the body through the eighteen
apertures or orifices of the tubes before described,
having their tops or ends directed upwards towards the
head. Two other branches, also, of the breathing
pipes, that are smaller and have no point of respira-
tion, cast a skin likewise. If any one separates the
cast little ropes, or congeries of breathing pipes with
a fine needle, he will very distinctly see their several
Exuvia and pulmonary vessels of the rhinoceros beetle (Oryctcs na$i-
cornis). A, magnified view of a pulmonary branch and vesicle; ",
pulmonary branch, composed of a membranous sheath and cartilagi-
nous lings 5 6. vesicle. B, larva; c c, nine reddish breathing holes.
C, exuvia, or cast skin of the larva, A d d d, skins of the pulmonary
tubes.
176 INSECT TRANSFORMATIONS.
branches and ramifications, and also their ringed struc-
ture.'*
The caterpillars of moths and butterflies generally
cast their skins five times; but some cast them seven
and even ten times, as in the case, according to
Cuvier, of the great tiger-moth (Jlrciia Caja, STE-
PHENS). By the breeders of silk-worms this natural
process is ranked among their maladies; and not alto-
gether without reason, as it frequently proves fatal,
from causes to which we have already alluded. For
several hours, often for a whole day, after casting the
skin, the caterpillar continues sluggish and moves little;
and as the vessels are still replete with the fat previ-
ously absorbed, there is no stimulus for it to eat. But
as soon as this supply is exhausted, it commences
again to eat voraciously, in order to supply another
store of fat for its succeeding moult.
The moulting of caterpillars, it may be remarked,
bears but a slight resemblance to the casting of the
feathers in birds, and the hair in quadrupeds. Birds
generally cast their feathers once, and many twice,
a-year, namely in autumn and in spring;! and quad-
rupeds in a similar way cast their hair. But in
both these cases the process is gradual, and resem-
bles that of shedding the milk-teeth when the jaw
enlarges. All of these changes, however, produce
considerable derangements in the animals; and they
are seldom accomplished without disordering health,
and sometimes endangering life. The great differ-
ence between the changes in insects and the other
classes of animals evidently arises from the differ-
ence of their internal structure. It must be obvi-
ous to all, for example, that the human body wears.
As old age advances the bones waste away and
become smaller, the muscles and skin shrink and
* Swammerdam, Bib. Nat., vol. i, p. 135.
t Temminck, Manuel d'Qrnithol. Intr.
MOULTING OF GRUBS. 177
grow dry and shrivelled, and the stature grows shorter
and more diminutive. Even in youth similar changes
are in progress, a system of absorbent vessels being
pro\ 7 ided tor removing worn materials from all parts
of the body, and carrying at least one portion of these
along with the blood into the lungs, whence it goes
off in minute particles with the breath. JNo similar
process of removing worn materials has, so far as we
know, been discovered in caterpillars; and it is, in-
deed, improbable, as the successive changes of the
skin accomplish all that is wanted in this respect. That
the worn materials, however, of the cast skins are
not altogether useless, appears from the singular
circumstance of the new-clothed caterpillar often
devouring them, as that of the hawthorn-butterfly
(Pieris Cratcegi, STEPHENS) does the shell of the
egg it has just been hatched from.* It may be
remarked, that it is chiefly the larger caterpillars of
the puss and some of the hawk-moths which have
been observed to eat their skins; none of the spi-
nous or hairy ones seem to relish this strange sort of
food. In the case of the warty -eft (Tiifon palustris,
FLEM.), which frequently casts its outer skin, we have
observed that it is frequently eaten by the animal
itselft
The grubs of some two winged flies (Muscidce) y
and of wasps, bees, ants, and ichneumon flies, do
not change their skins like the larvas we have just
been considering; but spiders and other allied tribes
(Jlrachnidce) , though they exhibit no other appear-
ance of larvas, moult frequently during their growth.
Goldsmith, amongst other curious mis-statements
respecting a house-spider which he himself observed,
asserts that it c lived three years, every year it changed
its skin, and got a new set of legs: 1 have sometimes
plucked off a limb, which grew again in two or three
* Bonnet, CEuvres, vol. ii> p. 18. t J R.
178 INSECT TRANSFORMATIONS.
days.' The fact is, that few spiders live one year,
much less three; and all their changes of skin are
gone through in a few months, and their acquiring
new legs for mutilated ones takes some weeks. It is
probable, indeed, that Goldsmith never thought of as-
certaining the identity of this spider; if the whole story
be not a mere fancy, like his assertion that spiders,
' when they walk upon such bodies as are perfectly
smooth, as looking-glass or polished marble, squeeze a
little sponge which grows near the extremity of their
claws, and thus diffusing a glutinous substance, adhere
to the surface till they make .a second step.'* Nei-
ther spiders nor any insects with which we are ac-
quainted can thus produce gum from their feet to aid
them in walking upon glass, though the house-fly can
Goat moth caterpillar (Cossus ligniperda) escaping from a
drinking glass, by spinning a ladder of silken ropes.
* Animated Nature, pt vi, ch. iii. See also Insect Archi
tecture, pp. 367-8.
MUSCULAR STRENGTH OF INSECTS. 179
walk thus by causing a vacuum between its feet and
the glass, as we shall subsequently describe at length.
But the spider and all caterpillars can only climb in
such cases by constructing a ladder of ropes, as is re-
presented by Rb'sel in the instance of the goat moth
caterpillar.
One of these caterpillars, which we possessed,*
made its escape in a manner much more unexpected,
if not so ingenious, by means of its great muscular
power, in which, it is not a little singular, that
insects, as Baron Haller remarks, appear to excel in
proportion to their diminutiveness. Of this we have
a remarkable example in the common flea, which
can draw seventy or eighty times its own weight. f
The muscular strength of this agile creature enables
it not only to resist the ordinary pressure of the
fingers in our endeavours to crush it, but to take
leaps to the distance of two hundred times its own
length; which will appear more surprising when we
consider that a man, to equal the agility of a flea,
should be able to leap between three and four hun-
dred yards. The flea, however, is excelled in leap-
ing by the cuckoo-spit frog-hopper ( Tettigonia spu-
maria, OLIVIER), which will sometimes leap two or
three yards, that is, more than 250 times its own
length ;J as if (to continue the comparison) a man
of ordinary stature should vault through the air
to the distance of a quarter of a mile. The minute
observation by which such unexpected facts are dis-
covered has in all ages been a fertile source of ridi-
cule for the wits, from the time when Aristophanes
in his Clouds introduced Socrates measuring the
leap of a flea, up to Peter Pindar's lampoon on
* See Insect Architecture, p. 189.
t Haller, Physiol., vol. ix, p. 2.
J De Geer, Mem., vol. hi, p. 178.
$ Aristophanes, Nfpx*/, *, .
180 INSECT TRANSFORMATIONS.
Sir Joseph Banks and the emperor-butterfly. To
all such flippant wit we have merely to retort the
question of the Abbe de la Pluche, ' if the Deity
thought insects worthy of his divine skill in form-
ing them, ought we to consider them beneath our
notice?'*
MoufFet, in his Theatre of Insects,! mentions that
an English mechanic, named Mark, to show his skill,
constructed a chain of gold as long as his finger,
which, together with a lock and key, were dragged
along by a flea; and he had heard of another flea
which could draw a golden chariot, to which it was
harnessed. Bingley tells us that Mr Boverich, a
watchmaker in the Strand, exhibited some years ago
a little ivory chaise with four wheels, and all its
proper apparatus, and the figure of a man silting on
the box, all of which were drawn by a single flea.
The same mechanic afterwards constructed a minute
landau, which opened and shut by springs, with
the figures of six horses harnessed to it, and of a
coachman on the box, a dog between his legs, four
persons inside, two footmen behind it, and a postilion
riding on one of the fore horses, which were all
easily dragged along by a single flea.J Gold-
smith remarks upon these displays of pulician
strength, that the feats of Samson would not, to a
community of fleas, appear to be at all miraculous.
Latrellle tells us a no less marvellous story of
another flea, which dragged a silver cannon twenty-
four times its own weight, mounted on wheels, and
did not manifest any alarm when this was charged
with gunpowder and fired oflf.|| Professor Bradley,
of Cambridge, also mentions a remarkable instance
of insect strength in a stag-beetle (Lucanus Cervus)
* Spectacle de la Nature, i, 3. + Page 275.
t Animal Biography, iii, 468. (Animated Nature, iv, 178.
|i Nouv. Diet. d'Hist. Nat. xxviii, 249.
MUSCULAR STRENGTH OF INSECTS. 181
which he saw carrying a wand a foot and a half long,
and half an inch thick, and even flying with it to the
distance of several yards. *
It has been remarked, with reference to these facts
of comparative size and strength, that a cock-chafer
is six times stronger than a horse ; and Linnaeus
observes, that if an elephant were as strong in
proportion as a stag-beetle, it would be able to
tear up rocks and level mountains. The muscular
power of fish, however, seems to bear a near compa-
rison with that of insects. c I have seen,' says Sir
Gilbert Blane, c the sword of a sword-fish sticking
in a plank which it had penetrated from side to side ;
and when it is considered that the animal was then
moving through a medium even a thousand times
more dense than that through which a bird cleaves
its course at different heights of the atmosphere, and
that this was performed in the same direction with
the ship, what a conception do we form of this dis-
play of muscular strength. 'y It should, however,
be observed, that the muscular power of the sword-
fish is principally shown in the rate of swimming, by
which the animal overtakes the ships, and thus ac-
quires the momentum which determines the force
of the blow. We may understand the proximate
cause of the strength of insects, when we look
at the prodigious number of their muscles the
fleshy belts or ribbons by whose means all animal
motions are performed. The number of these in-
struments of motion in the human body is reckoned
about 529 ; but in the caterpillar of the goat-moth,
Lyonnet counted more than seven times as many :
in the head, 228 ; in the body, 1647 ; and around
the intestines, 2186 ; which, after deducting 20,
* Bradley, Phil. Account, p 184.
t Gilbert Blane, Select Diss. p. 281.
VOL. VI. 16
182
INSECT TRANSFORMATIONS.
Magnified view of the principal dorsal muscles of the upper half of tho
Cossus, from Lyonnet.
MUSCULAR STRENGTH OF INSECTS. 183
common to the head and gullet, gives a total of
4061.*
' Any lady,' says Kirby and Spence, c fond of
going to be tempted with an exhibition of fine lace,
would experience an unexpected gratification could
she be brought to examine the muscles of a caterpillar
under the microscope : with wonder and delight she
would survey the innumerable muscular threads that
in various directions envelope the gullet, stomach,
and lower intestines of one of those little animals;
some running longitudinally, others transversely,
others crossing each other obliquely, so as to form
a pattern of rhomboids or squares ; others, again,
surrounding the intestine like so- many rings, and
almost all exhibiting the appearance of being woven,
and resembling fine lace, one pattern ornamenting
one organ ; another, a second ; and another, a
third.'!
We put the caterpillar of the goat-moth, to which
we have before alluded, under a bellglass, which weigh-
ed nearly half a pound, and of course more than ten
times the weight of the insect ; yet it raised it up
with the utmost ease. We then placed over the glass
the largest book which we had at hand c London's
Encyclopedia of Gardening,' consisting of about 1500
pages of strong paper, and weighing four pounds; but
this did not succeed in preventing the escape of the
animal, which raised the glass, though loaded with the
book, nearly a hundred times its own weight, and made
good its exit. J The multiplicity of its muscles above
enumerated, two hundred and thirty-six of which are
situated in the legs alone, will enable us to understand
how this extraordinary fete was performed. Even this
power of muscle, however, would doubtless have been
* Lyonnet, Traite Anat. de la Chenille, pp. 188, 584.
t Intr. iv, 186. $ J. R.
184 INSECT TRANSFORMATIONS.
unavailing in raising the loaded glass, except in con-
nexion with two favourable circumstances under which
the experiment was performed, and which are neces-
sary to be borne in mind to render the operation per-
fectly credible : 1st, that the wedge-like form of the
caterpillar- s head, in connexion with the peculiar shape
of the glass, enable it to lift it ; and 2d, that, one
side of the glass resting on the table, the insect only
bore half the weight of the glass and book.
Caterpillar of Cossus escaping from under a loaded glass.
A peculiar toughness of external covering some-
times supplies the place of this muscular power in
caterpillars. A singular instance occurs in the
history of a common downy two- winged fly, with
gray shoulders and a brown abdomen, (Eristalis
tenaXy FABE,.). The grub, which is rat-tailed, lives
in muddy pools, with the water of which it has some-
times been taken up by paper-makers, and, though
subjected to the immense pressure of their ma-
MUSCULAR STRENGTH OF INSECTS. 185
chinery, it has survived in a miraculous manner.
Such is the account originally given by Linnaeus.*
A recent compiler, mistaking Kirby and Spence's
very apt comparison of this grub to a London porter
nicknamed Leather-coat-Jack, from his being able to
suffer carriages to drive over him without receiving
any injury, forthwith fancies the porter to be ' another
insect, called leather- coat-jack,' which ( will bear
heavy carriage wheels to pass over it with impunity.'
Since the grub in question is rather soft, it must be
the tough texture of the skin which preserves it, as
in the similar instance of the caterpillar (figured at
page 125) of the privet hawk-moth (Sphinx Ligustri),
which Bonnet squeezed under water till it was as flat
and empty as the finger of a glove, yet within an hour
it became plump and lively as if nothing had happen-
ed.!
The instances, however, which we have just re-
corded are peculiar rather than general, for caterpillars
are for the most part very easily bruised and other-
wise injured. Those which are large and heavy,
therefore, such as the caterpillars of the hawk-moths
(Sphingidai), have the power of attaching themselves
very firmly to the spots where they feed and rest by
means of the numerous hooks of their pro-legs,J so
that it is almost impossible to detach them from the
branch to which they are clinging; and hence col-
lectors always cut the branch itself. All of them
have the means of breaking their fall by spinning a
cable of silk, which they uniformly do when acciden-
tally forced to quit their situation. Their method of
climbing up this cable again is worthy of observation,
for it differs considerably from the manoeuvre of spi-
ders, under the same circumstances; as must be ob-
* Fauna Suecica, 1799.
t lionnet, (Euvres, vol. ii, p. 124.
$ See Insect Architecture, p. 307, right-hand figure.
VOL. VI. 16*
186
INSECT TRANSFORMATIONS.
vious when we consider that the spinneret of the spi-
der is placed near its tail, while that of the caterpillar
is in its mouth. The spider accordingly drops head
downwards,* but when it wishes to remount the line,
it turns round, and raising its head, it stretches its long
triple-clawed legs| up the line, which it bundles up
while it ascends. The caterpillar on the other hand,
having very short legs, with only one smooth clawj
would make but slow progress in this manner, which
it does not attempt; but bending its head downwards
till it can grasp the cord with its hinder pair of feet,
Methods used by spiders and caterpillars for ascending their
threads. The caterpillars are those of ths emperor-moth (Satur-
nia Pavonia).
Insect Archil., page 336. f Ibid, p. 367.
* Ibid, p. 307, left-hand figure.
MEANS OF DEFENCE OF CATERPILLARS.
187
and then raising its head to the perpendicular position
again, it thus effects one step., and proceeds in the
same manner till it reaches the top.
Other caterpillars, when they are disturbed, employ
a different method of breaking their fall without
spinning a thread, taking advantage, for this purpose,
of the long hairs which cover their body. Those
who have seen a hedge-hog (Erinaceus Europceus),
when attacked by a dog, roll itself up into a prickly
ball, will readily conceive the manoeuvre of the cater-
pillars to which we allude, it being precisely similar.
a, Caterpillar of the tiger-moth (Arctia Caja). 6, the same
rolled up for defence, c, grub of the- museum-beetle. <L the
same magnified. C) tail of H;e same, magnified. /, $-, its hairs
188 INSECT TRANSFORMATIONS.
Should one of those hairy caterpillars, when feeding
near the top of a plant, be disturbed or alarmed, it
instantly coils itself up into a ball and drops among
the grass. Here it is not only difficult to discover,
but equally so to lay hold of it; for the pliancy and
smoothness of the hair causes it to slip through the
fingers as readily almost as quicksilver. The grub
of the museum beetle (Jlnthrenus Museorum, FABR.),
the pest of our cabinets, affords another example of
the same circumstance, being covered with tufts of
diverging hairs which cause it to glide through the
fingers as if they had been oiled. The six long tufts
at the tail, which it can erect at pleasure, are com-
posed of hairs, which rise from a bulb of the form of
a halberd, and are curiously jointed with cones through
their whole extent. The bead wood-louse (Armadil-
lo vulgaris, CUVIER), though not furnished with
hairs, rolls itself up into a round ball, trusting to the
fine polish of its back for escape, and to its hardness
for defence. c One of our maid-servants,' says
Swammerdam, ' once found a number of these wood-
lice in the garden contracted into round balls, and
thinking she had found a kind of coral beads she be-
gan to put them one after another on a thread; it soon
happened that the little creatures, being obliged to
throw off the mask, resumed their motions: on seeing
which, she was so greatly astonished, that she flung
down both them and the thread in great haste, crying
out, and running away.'*
The hairs with which the caterpillars of some of
our finest native butterflies are furnished, are some-
what of the nature of bristles or thorns, being hard,
inflexible, and sharply pointed. This is the case with
the caterpillars of all the fan-winged butterflies
(Vanessce). We have alluded to that of the pea*
* Swammerdam, pt i, p. 174.
MEANS OF DEFENCE OF CATERPILLARS. 189
cock's eye, which must be conspicuous to birds from
its dark black colour, prettily dotted with white, aided
besides by the gregarious habit of feeding in a
colony of several dozens together; but if a thrush or
a sparrow pounces upon one of them, the formidable
spines must present an obstacle somewhat unex-
pected, perhaps, to the making of a comfortable
meal. The ass, indeed, seems to relish the piquant
stimulus of the thorns or thistles, and sheep, goats,
and deer will browse on the still sharper leaves of
holly ;* but we think none of our soft-billed birds
would venture on a thorny caterpillar. Madame
Merian says 'that the spines of the caterpillar of
Urania Leilus are as hard as iron wire.'t Abbot
tells us that many American caterpillars sting like a
Thorny hairs of caterpillars. a a a, spiny caterpillar, from
Madame Merian. 6 6, Vanessa lo. c, spines magnified.
* Withering, Pot. Arrangement. Note on Ilex aquifolium.
t Merian, Insect. Surinam, xxix.
I-
190 INSECT TRANSFORMATIONS.
nettle, and blister the skin when touched; which is
also partly exemplified in that of our own gipsey moth
(Hypogymna dispar), the slender hairs of which
irritate and inflame the skin. The spines, in some of
the caterpillars alluded to, are like smooth thorns or
prickles; but on others, they are beset, or feathered
with shorter spines.
It is probably for some purpose of defence or con-
cealment that the larvae of several insects form a sin-
gular covering for themselves of their own excrements,
which they pile up for that purpose upon their backs.
This material, as Kirby has observed, is not always so
offensive as might be supposed, being in some in-
stances ( Cassida maculata et Lnalidium Leayanutn)
formed into fine branching filaments, like lichens or
dried fucus.* Others, however, which Reaumur
aptly terms Hottentots, do not appear quite so cleanly.
One of these, rather uncommon, was observed,
many years ago, by Vallisnieri, which he calls the
cantharidis of the lily (Crioceris merdigera, LEACH),
and may be found in May on Solomon's-seal, and
other liliaceous plants, which it devours and renders
unsightly. Under its singular canopy, it has no
resemblance to an insect, but looks like an oblong
ball of chewed grass stuck on the lily. The beetle
which is produced from the grub is of a fine brownish
scarlet, and elegantly sculptured with minute dots.
Another species, more abundant, similar in man-
ners, and less than half the size of the preceding
(C. cyanella, PANZER), is of a fine blue colour, with
similar dottings. The grub of the green tortoise-
beetle (Cassida equestris, FABR.), usually found on
burdocks, is furnished with a more ingenious me-
chanism for this purpose, consisting of a fork in its
tail, which it can depress or elevate, so as to carry its
strange canopy higher or lower, at pleasure. Like
* Linu. Trans, iii, 10.
MEANS OF DEFENCE OF CATERPILLARS. 19!
the two preceding insects, this grab is also most unex-
pectedly transformed into a very pretty green beetle,
of the form of a tortoise, the wing-cases of which
project all round as a covering for the legs.
A C
A, Cassida equestris. B, its grub magnified to show its anal
forks. C, the same with its canopy of excrements.
The larva of the golden-eyed fly ( Chrysopa perla,
LEACH), whose very singular eggs we formerly men-
tioned, covers itself with the fragments of the aphides
which it has devoured, a moving sepulchre of dry
bones.*
A very familiar instance of this mode of defence
occurs in the larva of the cuckoo-spit frog-hopper
( Tettigonia spumaria, OLIVIER), so frequently seen
in summer on willows, rose-trees, lychnis, grass, and
other plants. This creature is of an exceedingly soft
structure; and it is probably, therefore, as a protection
from the sun, that it throws up all around it the little
tuft of white froth, called, from a popular mistake,
cuckoo-spit. The perfect insect is covered with hard
wing-cases, of a brown colour, with a white spot and
pale double band.
It would appear that the hair, which we have de-
scribed above as covering the bodies of some cater-
pillars, is partly intended by nature to defend them
from cold during the winter. The truth of this
* Reaumur, iii, 380, &c.
192 INSECT TRANSFORMATIONS.
a, The spit frog-hopper (Tettigonia spumariu) flying. 6, froth
covering the grub of the same.
amounts almost to demonstration, from a circumstance
discovered respecting ants by the younger Huber-
< The larvae of some ants,' says he, ' pass the
winter heaped up in the lowermost floor of their
dwelling. 1 have found, at this period, very small
larvae in the nests inhabited by the yellow ant (For-
mica flava)j the field ant (F. c&spitwnt) , and some
other species. Those that are to pass the winter in
this state are covered with hair, which is not the case
in summer; affording another proof of that Provi-
dence at which naturalists are struck at every step.'*
The same growth of a warmer clothing for the
winter is well known to occur among quadrupeds,
particularly those which inhabit the higher northern
latitudes, f
Upon the same principle, a number of the cater-
pillars whick are hatched late in autumn, and are
destined to live over winter, are provided with a
warm clothing of hair or down This is the case
even with most of those which construct for them-
* M. P. Huber on Ants, p. 82.
t See Menageries, vol. i, p. 50.
MEANS AND DEFENCE OF CATERPILLARS. 193
selves a snug nest of silk, such as the caterpillars of
the brown-tail moth (Porthesia auriflua), and those
of the mallow butterfly (Hesperia malvce). But there
are others which are provided with no extraneous
covering, farther than the occasional shelter they may
obtain by crawling under withered leaves, the copings
of walls, or the bend of a branch. Among these
some are thickly covered with hair, of which we have
an instance in the caterpillar of the great tiger moth
(Jlrctia caja y STEPHENS), whose mode of rolling it-
self up into a ball we have already described; but a
more remarkable example occurs in the caterpillar of
the drinker moth (Odonestis potatoria, GERMAR.),
whose very feet are covered with fine shaggy dow\
It is this, no doubt, which preserves it from becoming
torpid during winter,; and as it feeds on grass, it can
always procure food during the severest weather.
When a fine sunny day chances to break in upon the
gloom of winter, this pretty insect may be often seen
stretched at its full length on a low twig, or the with-
ered stem of a nettle, basking in the sunshine with
apparent delight. We kept one of them in our study
during the winter of 1827-8; and it continued to feed
sparingly till February, when, owing to neglect, it un-
fortunately died.
There are several other caterpillars, however,
which live during the winter, in a no less exposed
manner, without being provided with any covering of
hair; though some of these, we may remark, do not
continue to feed, but become wholly or partially tor-
pid, such as the caterpillar of the magpie moth
(Jlbraxas grossulariata). Of this species we have
observed numbers, about as thick as a crow-quill, re-
maining in the same position for weeks together, and
never moving, except when some very considerable
change of temperature, either colder or hotter, took
place. They do not seem to select the warmest places
* J. R.
VOL. VI. 17
194 INSECT TRANSFORMATIONS.
within their choice, being usually found on an expos-
ed currant branch, or under the upper cross-bar of a
paling. We observed one, during several months of
the winter of 1828-9, stationary under the lintel of a
door, where a continual current of air must have ren-
dered it exceedingly cold. We have endeavoured to
rouse some of these from their semi-torpidity by keep-
ing them in a warm room; but though they would
make a few lethargic and unwilling movements, none
of them would eat, and the change always proved
fatal.*
We might be led from this instance to conclude
that caterpillars, not covered with hair, become tor-
pid during winter; but such general conclusions from
o, Young caterpillar of the drinker. 6, the same full grown.
c, smooth "caterpillar of the angle shades. J, the moth of the
enrnp-
J. R.
HYBERNATION OF CATERPILLARS. 195
particular facts seldom accord with actual nature, and
ought never to be indulged in by naturalists who study
accuracy. Another caterpillar, not uncommon in
gardens, on the hollyhock and other plants, would at
once disprove such an inference: we allude to that of
the angle shades (Phlogophora meticulosa, OCHSEN-
HEIMER). This caterpillar, which is exceedingly
smooth, and is remarkable for changing in its last
moult from a clear green to a yellowish brown, we
have found during the whole winter in the folds of the
fresh leaves of hollyhocks, cabbage-lettuce, savoys,
&c, quite lively, and feeding in open weather by no
means sparingly. Its defence from cold may perhaps
consist in a superabundant supply of fat, which we
may infer that it possesses from the soft flabby aspect.
It is this circumstance which seems to protect whales
from the polar cold; as well as bears during their tor-
pidity.
Some caterpillars seem to have no less power of
resisting severe cold than eggs; as authentic instan-
ces are recorded of their revival after being frozen
stiff, a circumstance also reported of some serpents
in North America.* Dr Lister in this way revived
caterpillars frozen so hard as to chink like stones when
thrown into a glass ;| and Mr Stickney exposed some
grubs of a common crane-fly ( Tipula oleracea, LINN.)
to a severe frost, till they were congealed into masses
of ice, yet several of them survived. J Reaumur,
however, was unsuccessful in similar experiments on
the gregarious moth of the fir (C'nethocampa Pilyo-
campa, STEPHENS), so celebrated among the ancients
as a poison;^ for none of them survived a cold of 2
below zero/Fahr., by which they were frozen toice.||
* John Hunter, Obs. on Anim. F.con. p. 99.
t Goedart, Insect, p. 79. | Kirby and Spcnce, Intr. ii, p.
453.
Plin. Hist. Nat. 38, 9. II Mem. ii.
CHAPTER VIII.
Voracity of Caterpillars, Grubs, and Maggots.
INSECTS, in the early stage of their existence, may
be compared to an Indian hunter, who issues from his
hut, as they do from the egg, with a keen appetite.
As soon as he is successful in finding game, he gorges
himself till he can eat no more, and then laying him
down to sleep, only bestirs himself again to go through
a similar process of gorging and sleeping; just so the
larvae of insects doze away a day or more when cast-
ing their skins, and then make up for their long fast
by eating with scarcely a pause. Professor Bradley
calculates (though upon data somewhat questionable)
that a pair of sparrows carry to their young about three
thousand caterpillars in a week;* but this is nothing
when compared with the voracity of caterpillars. Of
the latter we have more accurate calculations than that
of Bradley, who multiplied the number of caterpillars
which he observed taken in one hour by the hours of
sunlight in a week. Redi ascertained by experiment
that the maggot of the common blow-fly (Musca car-
naria) becomes from 140 to 200 times heavier within
twenty-four hours ;f and the cultivators of silk-worms
know the exact quantities of leaves which their broods
devour. c The result,' says Count Dandolo, ' of the
most exact calculations is, that the quantity of leaves
drawn from the tree employed for each ounce of eggs
amounts to 1609 Ibs, 8oz ; divided in the following man-
* Account of the Works of Nature.
t Esperienze de Insetti, p. 23.
VORACITY OF CATERPILLARS. 197
Sorted leaves. Refuse.
Ibs oz Ibs oz
First age, 60 18
Second age, 18 30
Third age, 60 90
Fourth age, 180 27
Fifth age, 1098 102
Per ounce of eggs of sorted leaves, Ibs 1362 142 8
Refuse, 142 8
Lost from the leaves by evaporation, &c, 105
1609~~8
He adds to this curious taj)le, that from the 1362 Ibs
of sorted leaves given to the caterpillars, it is neces-
sary to deduct 155 Ibs, 7 oz, 4 drs of litter, consist-
ing of fragments of uneaten leaves, stalks, fruit, &c,
and consequently that they actually devour only 1206
Ibs, 4 oz, 4 drs. It is necessary also to mention that
of this quantity 745 Ibs, 8 oz of dung are carried from
the hurdles; and consequently there is only digested
771 Ibs, 7 oz, 4 drs of pure leaves, which produce
120 Ibs of silk cocoons, giving a loss by evaporation
from the worms in gas and vapour of 496 Ibs, 4 oz,
nearly three parts of this loss occurring in the six last
days of the fifth age.* These deductions, however,
do not affect the amount eaten by the caterpillars pro-
duced from 1 oz of eggs, which is upwards of 1200
Ibs. A single silk-worm, as we before mentioned,
consumes within thirty days about 60,000 times its
primitive weight.
When we take these facts into consideration, we
need not be surprised at the extensive ravages com-
mitted by other caterpillars, many of which are much
larger than the silk-worm, and all of them produced
in broods of considerable numbers. Mr Stephens,
in his valuable catalogue of British insects, a work of
* Count Dandolo's Art of rearing Silk- Worms, p. 322-24,
Eng. Transl.
VOL. VI. 17*
198 INSECT TRANSFORMATIONS.
very extraordinary accuracy, enumerates nearly 2000
species of native moths and butterflies; and as the fe-
males of these are for the most part very prolific, we
have little reason to be surprised at the occasional
extent of their depredations. The 2000 species just
mentioned are, besides, not more than a fifth of our
native insects, most of the grubs and maggots of which
are exceedingly voracious and destructive.
It appears to be indispensable for most insects to feed
copiously during their larva state, in order to supply a
store of nutriment for their subsequent changes; for
many of them eat nothing, and most of them little, after
they have been transformed into pupae and perfect in-
sects. What is no less wonderful, a corresponding
change takes place in the internal formation of their or-
gans of digestion. A caterpillar will, as we have seen,
devour in a month 60,000 times its own weight of
leaves, while the moth or the butterfly into which it is
afterwards transformed may not sip a thousandth part
of its weight of honey during its whole existence.
JVow, in the caterpillar, nature has provided a most
capacious stomach, which, indeed, fills a very large
portion of its body; but in the butterfly the stomach is
diminished to a thread. By a series of minute dis-
sections, conducted with great skill, Heroldt traced
these changes, as they successively occur, from the
caterpillar to the butterfly. In the caterpillar he found
the gullet, the honey stomach, the true stomach, and
the intestines capacious. Two days after its first
change all these are visibly diminished, as well as the
silk reservoirs, which, in a chrysalis eight days old,
have wholly disappeared; while the base of the gullet
is dilated into a crop, and the stomach still more con
tracted into a spindle form. When near its change
into the perfect insect the gullet is still more drawn
out, while the crop, still small, is now on one side of
VISCERA OF THE COSSUS. 199
View of the upper side. View of the under side.
Aj B, C, The aesopha-
gus and its appendages.
D, E, The stomach 5
a pair of muscles
wind spirally jound it,
and by their contrac-
tion squeeze the di-
gested food into the
intestines.
E, F, The first large
intestine. F,G, the se-
cond. G, H, the third.
1,1, The six smali in-
testines.
Viscera of the Cossus.
200
INSECT TRANSFORMATIONS.
A, A, Caterpillar of Vanessa urticae magnified, a fr, the intes
tines of the same, a, the gullet. 6 b b b, pulmonary tn!-es. c c,
ligament of the stomach, d d d d, transparent rings of the same.
e e, small intestines. //, their origin, g g h A, their windings. *,
the rectum.
INTESTINAL STRUCTURE.
201
the gullet; and in the butterfly is enlarged into a
honey stomach
Intestinal canals of the caterpillar, pupa, and butterfly.
1. Caterpillar. , the oesophagus. 6, the stomach, c rf, the
two large intestines.
2. Pupa two days old. #, the oesophagus. 6, the stomach, c d
the two large intestines.
3. Pupa eight days old. a, dilation of the oesophagus, forming
the crop or honey-stomach.
4. Pupa immediately before its transformation. , the honey-
stomach become a lateral appendage of the oesophagus. 6
the stomach, c d, the large intestines.
5. Butterfly, a, honey-stomach. 6, the digesting stomach, c d,
the large intestines, become very long.
It is remarkable that in men of such extraordinary
appetite as amounts to a disease (Bulimia, CULLEN),
the natural capacity of the stomach, which, accord-
ing to Blumenbach, contains about three pints,*
is very much enlarged. This was peculiarly the
case with Tarare, an Italian juggler, who, from swal-
lowing flints, whole baskets of fruit, &c, seems
to have enlarged the capacity of his stomach so as
to render his appetite insatiable. M. Tessier, of the
Infirmary at Versailles, where Tarare died of con-
sumption, found on examination that his stomach
Blumenbach, Physiol., s. xxiii.
202 INSECT TRANSFORMATIONS.
was prodigiously distended.* The same must have
been the case with the French prisoner at Liverpool,
who, on the testimony of Dr Cochrane, consumed,
in one day, sixteen pounds of raw meat and tallow
candles, besides five bottles of porter.t
The mandibles of caterpillars, which do not act
perpendicularly like the jaws of quadrupeds, but ho-
rizontally, are for the most part very sharp and strong,
being of a hard, horny substance, arid moved by
powerful muscles. They are, for the most part,
slightly bent in the form of a reaping-hook; having
the concavity indented with tooth-shaped projections,
formed out of the substance of the jaw, and not socketed
as the teeth of quadrupeds. These are made to meet
like the blades of a pair of pincers; and in some cases
they both chop and grind the food.J Besides these
there is a pair of jaws (maxillae) placed on each side
of the middle portion of the under lip; and from their
being of a softer substance they seem to be more for
the purpose of retaining the food n than for mastication.
This formidable apparatus for masticating ( Troplii)
is well adapted to supply the large demands of the
capacious stomachs of larvae; and when we consider
that all of them are employed in eating at least for
ten or twelve hours in the day, and a great number
during the night, we need not wonder at their ex-
tensive ravages upon the substances on which they
feed. It may be interesting, however, to give a few
examples of their destructiveness; and with this view
it will be convenient to consider them under the three
popular names of caterpillars, grubs, and maggots.
CATERPILLARS.
The ravages of caterpillars are amongst the most
* M. Percy in Rapport d'Institute Nationelle.
+ Med. and Phys. Journ., iii, 209.
% Cuvier, Anat. Com., iii, 322.
RAVAGES OF CATERPILLARS. 203
conspicuous of insect depredations, in consequence
of their being committed upon the leaves of trees,
bushes, and plants, which are often stripped as bare
as in winter. .Even the smaller sorts of caterpillars
become, from their multiplicity, sometimes as destruc-
tive as those which are of considerable magnitude.
During the summer of 1827 we were told that an ex-
traordinary blight had suddenly destroyed the leaves
of all the trees in Oak of Honour Wood, Kent. On
going thither, we found the report had been little ex-
aggerated; for though it was < in the leafy month of
June,' there was scarcely a leaf to be seen on the
oak-trees, which constitute the greater portion of the
wood. But we were rather surprised when we dis-
covered, on examination, that this extensive destruc-
tion had been effected by one of the small solitary
leaf-rollers ( Tortrix viridana, HAWORTH) ;* for one
of this sor; seldom consumes more than four or five
leaves, if so much, during its existence. The num-
ber, therefore, of these caterpillars must have been
almost beyond conception; and that of the moths, the
previous year, must also, have been very great: for the
mother moth only lays from fifty to a hundred eggs,
which are glued to an oak branch, and remain during
the winter. It is remarkable that in this wood during
the two following summers these caterpillars did not
abound. "f
Instances, like this, however, from solitary species,
are, we believe, less common than those of the rava-
ges of gregarious caterpillars. In 1826, colonies of
the buff-tip (Pygccra bucephala, OCHSENHEIM.) were
in some parts of the country very abundant. We re-
marked them particularly at Harrow-on-the Hill, and
at Compton-Basset in Wiltshire. From their feeding
in company, they strip a tree, branch after branch,
* See figures of this caterpillar and its moth in * Insect
Architecture,' pp. 162-3.
t J. R.
204 INSECT TRANSFORMATIONS.
scarcely leaving the fragment of a leaf, till a great
portion of it is completely bare. Some of the magni-
ficent beeches in Compton Park, from this cause, ap-
peared with the one -half of their branches leafless
and naked, while the other half was untouched. Be-
sides the beech, these caterpillars feed on the oak, the
lime, the hazel, the elm, and the willow. When
newly hatched they may be readily discovered, from
their singular manner of marshalling themselves, like
a file of soldiers, on a single leaf, only eating it half
through; and in their more advanced stage, their
gaudy stripes of yellow and black render them very
conspicuous on the branches which they have nearly
stripped bare. The cuckoo feeds as greedily upon
them as they do on leaves, and may be seen early in
Ravages of the buff tip caterpillar (Py^tzru bucephala). a, the
full-grown caterpillar. 6, the moth, c c, a line of young cater-
pillars, advancing along a leaf and devouring it half through as
they march, d, the eggs.
RAVAGES OF CATERPILLARS. 205
the morning perched in the midst of their colonies,
and devouring them hy dozens.*
Those caterpillars which feed upon fruit-trees and
hedge shrubs are still more likely to attract attention;
since, when any of these are abundant, it is scarcely
possible to stir out of doors without observing them.
Thus, in the suburbs of London, in the summer of
1829, not only the orchards and gardens, but every
hedge, swarmed with the lackey caterpillars ( Clisw-
campa neustria), which are what naturalists term
polyphagous feeders, that is, they do not confine them-
selves to a particular sort of tree, but relish a great
number. The hawthorn, the. black thorn, and the
oak, however, seem to be most to their taste; while
they are rare on the willow, and we have never ob-
served them on the poplar, or the elder.
Another of what may be appropriately termed the
encamping caterpillars, of a much smaller size,
and of a different genus, is the small ermine ( Ypono-
meuta padella), which does not, besides, feed quite
so indiscriminately; but when the bird-cherry (Pru-
nus padus\ its peculiar food, is not to be had, it will
put up with black thorn, plum-tree, hawthorn, and
almost any sort of orchard fruit-tree. With respect
to such caterpillars as feed on different plants, Reau-
mur and De Geer make the singular remark, that in
most cases they would only eat the sort of plant upon
which they were originally hatched.")* We verified
this, in the case of the caterpillar in question, upon
two different nests which we took, in 1806, from the
bird-cherry at Crawfbrdland, in Ayrshire. Upon
bringing these to Kilmarnock, we could not readily
supply them with the leaves of this tree; and having
then only a slight acquaintance with the habits of in-
sects, and imagining they would eat any sort of leaf,
we tried them with almost every thing green in the
* J. R. t De Geer, Mem. i, 319.
VOL. VI. 18
206 INSECT TRANSFORMATIONS.
vicinity of the town; but they refused to touch any
which we offered them. After they had fasted several
days, we at length procured some fresh branches of
the bird-cherry, with which they gorged themselves
so that most of them died. Last summer (1829) we
again tried a colony of these caterpillars, found on a
seedling plum-tree at Lee, in Kent, with black thorn,
hawthorn, and many other leaves, and even with those
of the bird-cherry; but they would touch nothing ex-
cept the seedling plum, refusing the grafted varieties.*
Encampment of the caterpillar of the small ermine (Yponomeuta
paddla) oik the Siberian crab.
A circumstance not a little remarkable in so very
nice a feeder is, that in some cases the mother moth
will deposit her eggs upon trees not of indigenous
growth, and not even of the same genus with her
J. R,
RAVAGES OF CATERPILLARS. 207
usual favourites. Thus, in 1825, the cherry-apple,
or Siberian crab (Pyrus prunifolia, WILLDENOW),
so commonly grown in the suburbs of London,
swarmed with them. On a single tree at Islington,
we counted above twenty nests, each of which would
contain from fifty to a hundred caterpillars; and
though these do not grow thicker than a crow-quill,
so many of them scarcely left a leaf undevoured, and,
of course, the fruit, which showed abundantly in
spring, never came to maturity. The summer fol-
lowing they were still more abundant on the haw-
thorn hedges, particularly near the Thames, by Bat-
tersea and Richmond, Since then we have only seen
them sparingly; and last summer we could only find
the single nest upon which we tried the preceding ex-
periment.* This present spring (1830) they have
again appeared in millions on the hedges.
Reaumur says that in some years they were ex-
ceedingly destructive to his apple-trees, though they
did not touch his pears, plums, or apricots,f which
agrees precisely with our own remarks. We are well
aware that there are several species of the small er-
mines, all similar in manners, such as the one which
feeds on the spindle- tree, (Euonymus}, and pro-
duces the prettiest moth of the genus ( Yponomeuta
Euonymellaj) but our preceding remarks all apply
to one species.
In 1829 we remarked a very extraordinary num-
ber of webs of some similar caterpillar, of which we
did not ascertain the species, on the willows in Hol-
land and the Netherlands, from Amsterdam to
Ostend. In some districts, particularly near Bruges
and Rotterdam, the leaves were literally stripped
from whole rows of trees; while other rows, at no
considerable distance, were entirely free from their
ravages. A foreign naturalist, quoted by Harris in
J. R. t Reaumur, Mem. ii, 198.
208 INSECT TRANSFORMATIONS.
his Aurelian, says, that the caterpillar of the Camber-
well beauty (Vanessa Jlntwpa), which feeds grega-
riously on the willow, sometimes defoliates the trees
of a whole district in the Low Countries; but the
ravages observed by us were evidently made by the
caterpillars of some small moth.*
None of the preceding details, however, appear so
striking as what is recorded of the brown-tail moth
(Porthesia auriflua}, by Mr W. Curtis,! whose
multitudinous colonies spread great alarm over the
country, in the summer of 1782. This alarm was
much increased by the exaggeration and ignorant de-
tails which found their way into the newspapers. The
actual numbers of these caterpillars must have been
immense, since Curtis says, i in many of the parishes
near London subscriptions have been opened, and
the poor people employed to cut off the websj at one
shilling per bushel, which have been burnt under the
inspection of the churchwardens, overseers, or beadle
of the parish: at the first onset of this business four-
score bushels, as I was most credibly informed, were
collected in one day in the parish of Clapham. 7
It is not, therefore, very much to be wondered at,
that the ignorant, who are so prone to become the
victim of groundless fears, should have taken serious
alarm on having so unusual a phenomenon forced
upon their attention. Some alarmists accordingly
asserted that the caterpillars c were the usual presage
of the plague j' and others that they not only pre-
saged it, but would actually cause it, for * their
numbers were great enough to render the air pesti-
lential, 5 while, to add to the mischief, ' they would
destroy every kind of vegetation, and starve the cattle
in the fields.' ' Almost every one/ adds Curtis,
* J. R.
t Curtis, Hist, of Brown-tail Moth, 4to. London, 1782.
t See Insect Architecture, page 330, for a figure of the nest.
RAVAGES OF CATERPILLARS. 209
c ignorant of their history, was under the greatest
apprehensions concerning them; so that even prayers
were offered up in some churches to deliver the
country from the apprehended approaching cala-
mity.'
It seems to have been either the same caterpillar,
or one very nearly allied to it, probably that of the
golden-tail (Porthesia Chrysorrhcea), which in 1731-
2, produced a similar alarm in France. Reaumur, on
going from Paris to Tours, in September 1730, found
every oak, great and small, literally swarming with
them, and their leaves parched and brown as if some
burning wind had passed over them; for when newly
hatched, like the young buff-tips, they only eat one
of the membranes, of the leaf, and of course the other
withers away* These infant legions, under the shel-
ter of their warm nests,* survived the winter in such
numbers, that they threatened the destruction not
only of the fruit-trees, but of the forests, every tree,
as Reaumur says, being over-run with them. The
Parliament of Paris thought that ravages so widely
extended loudly called for their interference, and
they accordingly issued an edict, to compel the people
to uncaterpillar (decheniller) the trees; which Reau-
mur ridiculed as impracticable, at least in the forests.
About the middle of May, however, a succession of
cold rains produced so much mortality among the
caterpillars, that the people were happily released
from the edict; for it soon became difficult to find a
single individual of the species. "f In the same way the
cold rains, during the summer of 1829, seem to have
nearly annihilated the lackeys, which in the early part
of the summer, swarmed on every hedge around
London. J The ignorance displayed in France at the
time in question, was not inferior to that recorded by
* Sec Insect Architecture, p. 331, for a figure.
I Reaumur, ii, p. 137. Insect Architecture, p. 329.
VOL. VI. 18*
210 INSECT TRANSFORMATIONS.
Curtis; for the French journalists gravely asserted
that part of the caterpillars were produced by spiders;
and that these spiders, and not the caterpillars, con-
structed the webs of the slime of snails, which they
were said to have been seen collecting for the pur-
pose! 'Verily,' exclaims Rraumur, ; there is more
ignorance in our age than one might believe.'
It is justly remarked by Curtis, that the caterpillar
of the brown-tail moth is not so limited a feeder as
some, nor so indiscriminate as others; but that it always
confines itself to trees or shrubs, and is never found on
herbaceous plants, whose low growth would seldom
supply a suitable foundation for its web. Hence the
absurdity of supposing it would attack the herbage
of the field, and produce a famine among cattle.
Curtis says, it is found on the c hawthorn most plen-
tifully, oak the same, elm very plentifully, most fruit-
trees the same, black thorn plentifully, rose-trees the
same, bramble the same, on the willow 'and poplar
scarce. None have been noticed on the elder, walnut,
ash, fir, or herbaceous plants. With respect to fruit-
trees the injuries they sustain are most serious, as, in
destroying the blossoms as yet in the bud, they also
destroy the fruit irj embryo; the owners of orchards,
therefore, have great reason to be alarmed.'
The sudden appearance of great numbers of these
caterpillars in particular years, and their scarcity in
others, is in some degree explained by a fact stated
by Mr Salisbury. ' A gentleman of Chelsea,' he
says, ' has informed me that he once took a nest
of moths and bred them; that some of the eggs
came the first year, some the second, and others of
the same nest did not hatch till the third season.'*
We reared, during 1829, several nests both of
the brown-tails and of the golden-tails, and a num-
ber of the females deposited their eggs in our nurse-
* Salisbury, Hints on Orchards, p. 53.
RAVAGES OF CATERPILLARS. 211
cages ; but, contrary to the experiment just quoted,
all of these were hatched during the same autumn.*
The difference of temperature and moisture in par-
ticular seasons may produce this diversity.
An alarm, similar to those we have recorded, was
produced in France in 1735 by the green striped
caterpillars of a moth very common in Britain, called
by collectors, from a mark on its upper wings, the Y, or
more properly the y moth (Plusia Gamma, OCHS.).
Though ranked in some classifications amongst the
nocturnal moths, it flies chiefly by day, and may be seen
in Battersea-fields, or other moist meadows, flitting
from herb to herb and flower to flower, in short and
low flights; for it seldom soars higher than the tallest
grass-stem, or the crimson flower-heads of the knap-
weed, upon whose honey it sometimes regales, re-
maining on the wing all the while it is sipping it.
During the cold rainy summer of 1829 it was almost
the only moth which appeared plentiful. "j* At least
two broods seem to be produced during the season ;
which may account for its being found from May till
the setting-in of the winter frosts.
Notwithstanding it being so plentiful, however, we
have not heard of its having ever been so destruc-
tive here as in France, were, as usual, the most
improbable causes were assigned for its increase.
* In some places,' says Reaumur, c they assured me
they had seen an old soldier throw the spell ; and in
other places an ugly and mischievous old woman had
wrought all the evil.'J These supposed supernatu-
ral agents, however, must have been either very nu-
merous or very active to fill, not only the gardens,
but every field, with legions of those caterpillars, which
devoured almost every green thing, and left only the
stalks as monuments of their devastation. The
alarm proceeded farther, for it began to be whispered
* J. R. t J. R. $ Reaumur, ii, 336.
INSECT TRANSFORMATIONS.
that they were poisonous ; and many were in conse-
quence afraid to touch soups or salads. Reaumur
thought it incumbent on him to refute this notion at
some length ; but we cannot accept his doctrine as
very palatable, when he tells us that few dishes of soup
or salad are ever prepared without containing cater-
pillars, and yet all the world are not poisoned there-
by, any more than by eating oysters or viper broth.
He endeavoured also to account by calculation for
their excess, from the data of the female moth lay-
ing about four hundred eggs. Now, if there were
only twenty caterpillars distributed in a garden, and
all lived through the winter, and became moths in
the succeeding May, the eggs laid by these, if all fer-
tile, would produce 800,000, a number much more
than sufficient to effect great destruction.* Did not
Providence, therefore put causes in operation to keep
Transformations of the y muih (Phisin Gamir>n). , the r<r;r, featly
magnified, on a morsel of laf. Z>, the er on n lea* 1 , i mural size, r, the
larva. <?, the pupa, e, the moth.
* Rv'amnur, ii, 327.
RAVAGES OF CATERPILLARS. 213
them in due bounds, the caterpillars of this moth alone,
leaving out of consideration the 2000 other British
species, would soon destroy more than half of our ve-
getation.
The caterpillar just mentioned, amongst other pot-
herbs attacks coleworts and cabbage; and may some-
times be found there along with another, not uncom-
mon, but seldom very destructive, called by collectors
the burnished brass (Plusia chrysitis), which differs
little from the caterpillar of the y moth, except in be-
ing of a brighter green. Another, called the old gen-
tlewoman (Mamestra brassicce, TREITSCHE), is so
destructive to cabbages in Germany, that the gar-
deners gather whole baskets full and hnry them j
but as Rb'sel remarks, they might as well endeavour
to kill a crab by covering it with sea-water, for it
is natural to them to burrow under ground when
they change into chrysalides.* We have seen this
caterpillar, as well as that of the brown-eye (Mames-
tra oleracea\ do considerable damage in Wiltshire,
but nothing to what is reported of it in Germany.
The leaves of cabbages, cauliflower, brocoli, cole-
worts, and turnips, are frequently devoured to a
more considerable extent by the sub-gregarious cater-
pillars of the white butterflies (Pontia brassicce, P.
napiy &c.) From the great multiplicity of the but-
terflies, indeed, and from there being two broods in
the year, we have reason to wonder that their
ravages are not more extensive. But we have re-
marked, that they seem more partial to wild than cul-
tivated plants ; for we have seen, near Islington, the
oleraceous weeds, such as rape (Brassica napus),
over-run with them in the very same fields with cul-
tivated cabbages, which were not touched ;| so that
the caterpillars are not always so injurious as we
might at first suppose, since in this case they tend to
* Rosel, Inseckten, i, iv, 170. t J. R.
214 INSECT TRANSFORMATIONS.
keep down the weeds, while the birds and the ichneu-
mon flies keep them in check by making prey of them.
The gregarious caterpillars of an allied species,
called the black-veined white butterfly (Pieris Cra-
tcegi, STEPHENS), is in some seasons and districts no
less destructive to orchards and hawthorn hedges than
the preceding ones are to the kitchen-garden. Sal-
isbury, who wrote at Chelsea in 1815, says it 'com-
mits great destruction every spring, and not only to
the apple-trees, but other kinds of fruits.'* Mr
Stephens, writing in 1827 says, * in June 1810,1
saw it in plenty at Coombe Wood, and in the follow-
ing year I captured several at Muswell-hill, since
which time I have not seen any at large, 'f Mr
Haworth also says, c it has not of late years been
seen at Chelsea, where it formerly abounded. We
have never met with at all. According to Salisbury
the female butterfly lays her eggs near the extremity
of an old rather than a young branch, and covers
them with a coating of gluten, which is both imper-
vious to moisture and impenetrable (this we doubt)
to the bills of birds. c In this state, 5 he adds, ' we
have instances of their remaining without losing
their vitality for several years, until a favourable op-
portunity of their being brought into existence ar-
rives. ' J The caterpillars, which are at first black and
hairy, live in common in a silken tent. They become
subsequently striped with reddish brown, and disperse
over the trees. This caterpillar and its butterfly are
figured in a subsequent page.
Our gooseberry and red- currant bushes are very
frequently despoiled of their leaves, both by the
speckled caterpillar of the magpie moth (Mraxas
grossulariata), and by what Reaumur terms the
* Hints on Orchards, p. 56.
1 Illustrations, i, Haustellata, 27.
j Hints on Orchards, p, 57.
RAVAGES OF CATERPILLARS. 215
pseudo-caterpillars of one of the saw-flies (Nematus
Ribesii, STEPHENS). The latter insect has a flat yel-
low body and four pellucid wings, the two outer ones
marked with brown on the edge. In April it issues
from the pupa, which has lain under ground from the
preceding September. The female of the gooseberry
saw-fly does not, like some of the family, cut a groove
in the branch to deposit her eggs; c of what use,
then,' asks Reaumur, ' is her ovipositor saw?'* In
order to satisfy himself on this point, he introduced
a pair of the flies under a bell-glass along with a
branch bent from a red-currant bush, that he might
watch the process. The female immediately peram-
bulated the leaves in search of a place suited to
her purpose, and passing under a leaf began to lay,
n a a, Saw-fly of the gooseberry (Nematus -Ribesii, Stephens). 6, its
eggs on the nervures of a leaf, d d, the caterpillars eating, c, one
rolled up. /, one extended.
* See Insect Architecture, chap, vii, for a description of this
curious instrument.
216 INSECT TRANSFORMATIONS.
depositing six eggs within a quarter of an hour.
Each time she placed herself as if she wished to cut
into the leaf with her saw ; but, upon taking out
the leaf, the eggs appeared rather projecting than
lodged in its substance. They adhered so firmly,
however, that they could not be detached without
crushing them. He could not discover any groove;*
but we think it likely that a minute cut is made in
the exterior membrane of the leaf, the edges of which
grasp and hold firm the part of the egg which is
thrust into it by the insect. Be this as it may, the
caterpillars are hatched in two or three weeks; and
they feed in company till after midsummer, frequently
stripping both the leaves and fruit of an extensive
plantation. The caterpillar has six legs and sixteen
prolegs, and is of a green colour mixed with yellow,
and covered with minute black dots raised like sha-
green. In its last skin it loses the black dots and
becomes smooth and yellowish white. The Caledo-
nian Horticultural Society have published a number
of plans for destroying these caterpillars.
An allied species of saw-fly (Ntmatus Caprece,
STEPHENS) frequently becomes extensively destruc-
tive to several species of willow, 'sallow, and osier.
It is so like that of the gooseberry and that of the
willow (Nematus salicis), which is not British, that it
has been confounded with these by Fabricius, Stew-
art, Gmelin, and other authors. In the summer of
1828, we observed a considerable group of young
standards of the golden osier (Salix vitellina}, in a
nursery at Lewisham, rendered quite leafless by these
caterpillars; which, when feeding, throw themselves
into singular postures by holding only with their
fore feet. The fly -appears in spring, and places its
eggs in a round patch on the back of the leaf, and
not along the nervures, like the gooseberry saw fly.
* Reaumur, v, 1 25.
RAVAGES OF CATERPILLARS.
217
During the three last summers, we also remarked
that the alders (Jllnus glutinosa] along the banks of
the Ravensbourne, in Kent, were extensively stripped
of their leaves by a saw-fly caterpillar, very like the
preceding, but of a larger size.* It appears to be
the same as one figured by Reaumurf ( Selandria
Alni ? STEPHENS).
, Nematus cerprece, on the osier ; 6, Selandria nlni ? on the alder*.
Another slimy caterpillar of a saw-fly, allied to
that of the cherry (Tenthredo Cerasi), is called the
slug worm in North America, where it has increased
*J. R.
VOL. VI.
Reaumur, vol. v, pi. 11, fi . 1, 2.
19
218 INSECT TRANSFORMATIONS.
so numerously as to threaten the entire destruction of
. fruit trees, including the cherry, plum, pear, and
quince. Where they are numerous, the air becomes
loaded with a disagreeable and sickly effluvium. The
history of this orchard pest has been admirably
written by Professor Peck.*
When a turnip crop has been fortunate enough to
escape the ravages committed on it in the seed leaf
by a small jumping beetle (Haltica nemorum, ILLI-
GER), and by a root weevil (Nedyus contractus,
STEPHENS), a no less formidable depredator some
times appears in a caterpillar belonging to the saw-
fly family (Tenthredinidce}, and apparently of the
genus Jfthalia. An instance .is recorded by Mar-
shall, in the Philosophical Transactions, of many
thousand acres having had to be ploughed up on
account of the devastations caused by these insects.
It is, he informs us, the general opinion in Norfolk,
that they come from over-sea; and a farmer averred
that he saw them arrive in clouds so as to darken
the air, while the fishermen reported that they had
repeatedly witnessed flights of them pass over their
heads when they were at a distance from land. On
the beech and the cliffs, indeed, they lay in heaps,
so that they might have been taken up with shovels;
while three miles inland they crowded together like
a swarm of bees.")"
We have little doubt, however, that these details
are put in an inverse order; as frequently occurs in
histories of the proceedings of insects by those but
little acquainted with their habits. Insects of this
family, indeed, seldom fly far, and could not at all
events cross the sea, unless it might be a narrow bay
or inlet; and if they had, we ought to have heard of
their departure as well as their arrival, since their
* Nat. Hist, of the Slug Worm, Boston, 1799.
i Phil. Trans, vol. Ixxiii, p. 317.
RAVAGES OF CATERPILLARS. 219
extraordinary number could not have failed to at-
tract public notice on other shores. The nature of
these insects is to lie in the pupa state during the
winter under ground; and when, at its appointed
time, the fly comes forth, it only lives to lay its eggs,
usually dying within a few days or weeks. It must
have been, therefore, after the laying their eggs on the
turnips, and not before, that clouds of the flies were
seen at sea and on the shore, though not arriving,
but going away. They were, doubtless, impelled by
that restless desire of change felt by all animals
when death is approaching, and which in tropcal
countries is yearly exemplified in the destruction of
locusts, for these always make for the sea, and
perish there. But though they were thus got rid
of in August, 1782, they left a progeny behind them
in the black caterpillars which were hatched from
their eggs. In the summer of 1783, accordingly,
we are told by Mr Marshall, that whole districts
were ravaged by them, the descendants, of course,
in the second generation, of the saw-flies which pe-
rished .on the beach and at sea the preceding au-
tumn.
Some caterpillars, which either conceal them-
selves under ground, or feed on roots and the wood
-of trees, do considerable injury, without apparent
cause; and often give occasion to the popular notions
respecting mysterious blights. In this manner will
the caterpillars of the ghost moth (Hepialus Humuli)
gnaw the roots of the burdock, and, what is of more
consequence, of the hop plant, till the shoots are
weakened and the leaves droop in bright sunshine.
We have repeatedly seen, in the gardens about Lee,
a large branch of the red-currant bush, though pre-
viously healthy and loaded with fruit, all of a sud-
den droop and wither, giving good cause to sur-
mise, except in the leaves not being brown or
220 INSECT TRANSFORMATIONS.
parched, that it had been struck with lightning. On
cutting into such branches, however, the cause was
uniformly found to be the ravages of the caterpillar
of the currant hawk -moth (JEgeria tipuliformis,
STEPHENS), which abounds in the vicinity. But we
have also remarked that it only occasionally produces
this effect upon the trees; for several bushes upon
which we have found old pupa-cases projecting from
the bark, remained healthy and uninjured.* Sir
Joseph Banks showed Mr Kirby a currant branch
perforated by this caterpillar to the pith, and said the
size of the fruit was in consequence diminished.!
In Germany it is reported to destroy even large
bushes of the red currant. There can be no doubt
that the caterpillars of the goat moth frequently
destroy willow, poplar, and oak trees, of considerable
magnitude; but the mother moth seems to prefer
laying her eggs upon those which have already
begun to decay. A black poplar tree, not thicker
than a man's leg, and stripped on one side of more
than a foot of the bark, was bored by above a dozen
caterpillars of the clear underwing (JEgeria- asili-
formis, STEPHENS), without seeming to have its
growth at all retarded. J
It does not appear that a minute moth, called by
Leeuwenhoeck, who writes its history, the wolf, and
by Haworth the mottled -woollen (Ph. Tinea granella,
LINNAEUS), is so abundant in Britain as to do much
damage to the grain stored in granaries, upon which
it feeds. But it seems to have created considerable
alarm on the Continent. It has been found near
London, and may increase with us. The cater-
pillar, which is smooth and white, ties together with
silk several grains of wheat, barley, rye, or oats, weav-
* J, R. t Kirby and Spence, vol. i. p. 197,
t See Ins. Archit., p. 192.
RAVAGES OF CATERPILLARS.
221
ing a gallery between them, from which it projects its
head while feeding; the grains, as Reaumur remarks,
being prevented from rolling or slipping by the silk
which unites them. He justly ridicules the absurd
notion of its filing off the outer skin of the wheat by
rubbing upon it with its body, the latter being the
softer of the two: and he disproved, by experiment,
Leeuwenhoeck's assertion that it will also feed on
woollen cloth. It is from the end of May till the
beginning of July that the moths, which are of a
silvery gray, spotted with brown, appear and lay their
eggs in granaries.
The caterpillar of another still more singular
grain moth (Tinea Hordei, KIRBY) proves some-
times very destructive to granaries. The mother
moth, in May or June, lays about twenty or more
eggs on a grain of barley or wheat; and when the
caterpillars are hatched they disperse, each selecting
a single grain. M. Reaumur imagines that san-
guinary wars must sometimes arise, in cases of pre-
occupancy, a single grain of barley being a rich
Transformations of the grain moths, , grain of barley includ-
ing a caterpillar 5 ft, c, the grain cut across, seen to be hollowed
out, and divided by a partition of silk ; d, the moth (Tinea
Hordei) ; e, grains of wheat tied together by the caterpillar $ f y
g, the moth (Euplocamus trranella).
VOL. VT.
19*
222 INSECT TRANSFORMATIONS.
heritage for one of these tiny insects; but he con-
fesses he never saw such contests.* When the
caterpillar has eaten its way into the interior of the
grain, it feeds on the farina, taking care not to gnaw
the skin nor even to throw out its excrements, so that
except the little hole, scarcely discernible, the grain
appears quite sound. When it has eaten all the
farina, it spins itself a case of silk within the now hol-
low grain, and changes to a pupa in November. |
Two other caterpillars of a different family, the
honeycomb moth (Galleria cereana, FABR.), and the
honey moth (G. alvearia, FABR.), the first having
square, and the second rounded wings,J do very
considerable damage to the hives of bees. The
moths of both, according to Reaumur, appear about
the end of June or beginning of July; and when in
danger they run rather than fly, gliding with such
celerity that they can easily elude the vigilance of
the bees, which, indeed, if we may trust Swam-
merdam, never attack them, nor prevent their en-
trance into the hives, unless they chance to brush
against them in their passage. But Reaumur ac-
tually saw the bees pursue one, though without
success. It becomes easy for a moth, at all events,
to lay eggs among the combs; or as Keys says, at
the entrance of the hive: this writer adds, c she
spins a close and strong web to defend the young ;'
which is impossible, as no insect, subsequent to its
larva state, can spin.
The caterpillar of the first species, < wherever it
passes,' says Swamrnerdam, ' gnaws round holes
through the waxen cells, one caterpillar sometimes
breaking open and destroying fifty or sixty eel-Is,
* See Insect Architecture, p. 231.
+ R> aumur, Mem., vol. ii, p. 486, &c.
$ Stephens's Catalogue, vol. ii, p. 213.
Keys, Treatise on Bees, p. 178, edit. 1814,
RAVAGES OF CATERPILLARS.
223
Wherever it penetrates it always fabricates a hollow
tubulated web, in which, as a rabbit in its burrow,
it can very swiftly pass from one part to another,
and speedily run back again. It fills the whole
comb with such webs, and turns itself in them
every way into various bendings and windings; so
that the bees are not only perplexed and disturbed in
their work, but they frequently entangle themselves
by the claws and hairs of their legs in those webs, and
the whole hive is destroyed.'
The other species he accuses of being not only
destructive to the wax, but to the bees themselves.
* I saw one of these little caterpillars,' he says,
i whilst it was still small, and was breaking the cells
in which the pupa of the bees lie, and eating the wax
Transformations of the honeycomb moths, a, , , a, Galleries of
the cell-boring caterpillar ; 6," the female : c, the male moth (Gal-
leria alvearia) ; d, rf, <?, d, galleries of the wax-eating cater-
pillar, e, seen at the entrance ; /, the same exposed ; g-, its
cocoon ; A, the moth (ChtUena cereana).
224 INSECT TRANSFORMATIONS
there, cover up these pupae with its excrements, so
that they could scarcely be known.' He adds with
great na'ivett', ' I have learned these matters much
against my inclination, and have been full of wrath
against the insect for thus defiling and killing some
bee pupas which I had designed to observe in their
changes.'*
M. Bazin, a friend of Reaumur's, discovered the
caterpillar of a moth of this order feeding on choco-
late, of which it seemed very choice, always pre-
ferring that which had the finest flavour. The moth
is sometimes produced in September, and some-
times in the beginning of the following summer.
It is probable that, like the cheese-fly, it might, in
default of chocolate, select some other aliment. "f
* Swammerdam, vol. i, p. 225. t Reaumur, vol. iii, p. 277.
CHAPTER IX.
Voracity of Caterpillars, Grubs, and Maggots 5 continued.
GRUBS.
WE frequently hear farmers and gardeners com-
plaining that their produce is destroyed by c the
grub;' they might with equal propriety accuse
c the bird' when their ripe seeds are devoured
by sparrows, chaffinches, linnets, and other seed-
eaters. Instead of one sort of grub, as the expression
seems to indicate, we are far under the mark in
reckoning a thousand species indigenous to Britain,
each peculiar in its food and its manners. We shall,
however, adhere as nearly as possible to the terms in
common use; but as the larvae of the crane-flies
(Tipulidce, LEACH), being without legs, cannot be
accurately ranked with the legged grubs of beetles,
we shall consider them as maggots, though they are
usually termed grubs by the farmers.
The most destructive, perhaps, of the creatures
usually called grubs, are the larvae of the may-bug
or cockchafer (-Melolontha vulgaris), but too well
known, particularly in the southern and midland
districts of England, as well as in Ireland, where
the grub is called the Connaught worm;* but fortu-
nately not abundant in the north. We only once
met with the cockchafer in Scotland, at Sorn, in Ayr-
shire.| Even in the perfect state, this insect is not
a little destructive to the leaves of both forest and
fruit trees. In 1823, we remember to have observed
almost all the trees about Dulwich and Camberwell
* Bingley, Anim. Biog. vol. iii, p. 230. t J. R.
226 INSECT TRANSFORMATIONS.
defoliated by them; and Salisbury says, the leaves of
the oaks in Richmond Park were so eaten by them,
that scarcely an entire leaf was left. But it is in their
previous larva state that they are most destructive, as
we shall see by tracing their history.
The mother cockchafer, when about to lay her eggs,
digs into the earth of a meadow or corn-field to the
depth of a span, and deposits them in a cluster at the
bottom of the excavation. Rosel, in order to watch
their proceedings, put some females into glasses half-
filled with earth, covered with a tuft of grass, and a
piece of thin muslin. In a fortnight, he found some
hundreds of eggs deposited, of an oval shape and a
pale yellow colour. Placing the glass in a cellar, the
eggs were hatched towards autumn, and the grubs in-
creased remarkably in size. In the following May
they fed so voraciously that they required a fresh turf
every second day; and even this proving too scanty
provender, he sowed in several garden pots a crop of
peas, lentils, and salad, and when the plants came up,
he put a pair of grubs in each pot; and in this man-
ner . he fed them through the second and third years.
During this period, they cast their skins three or four
times, going for this purpose deeper into the earth,
and burrowing out a hole where they might effect
their change undisturbed; and they do the same in
winter, during which they become torpid and do not
eat.
When the grub changes into a pupa, in the third
autumn after it is hatched, it digs a similar burrow
about a yard deep; and when kept in a pot, and pre-
vented from going deep enough, it shows great un-
easiness and often dies. The perfect beetle comes
forth from the pupa in January or February; but it is
then as soft as it was whilst still a grub, and does
not acquire its hardness and colour for ten or twelve
days, nor does it venture above ground before May,
RAVAGES OF GRUBS.
227
on the fourth year from the time of its hatching. At
this time, the beetles may be observed issuing from
their holes in the evening, and dashing themselves
about in the air as if blind.
Transformations of the cockchafer (Mt/olontha -vulgaris). a,
newly hatched larvae. 6, larva, one year old. c, the same larva
at the second year of its growth, d, the same three years old. e,
section of a bank of earth, containing the chrysalis of the fourth
year. /, the chafer first emerging from the earth, g-, the perfect
chafer in a sitting posture. A, the same flying.
During the three summers then of their existence
in the grub state, these insects do immense injury,
burrowing between the turf and the soil, and devour-
ing the roots of grass and other plants; so that the
228 INSECT TRANSFORMATIONS.
turf may be easily rolled off, as if cut by a turfing
spade, while the soil underneath for an inch or more
is turned into soft mould like the bed of a garden,
Mr Anderson, of Norwich, mentions having seen
a whole field of fine flourishing grass so under-
mined by these grubs, that in a few weeks it became
as dry, brittle, and withered as hay.* Bingley also
tells us that about sixty years ago, a farm near
Norwich was so infested with cockchafers, that the
farmer and his servants affirmed they gathered eighty
bushels of them; and the grubs had done so much
injury, that the court of the city, in compassion to
the poor fellow's misfortune, allowed him twenty -
five pounds. 'I In the year 1785, a farmer, near
Blois, in France, employed ar number of children and
poor persons to destroy the cockchafers at the rate
of two liards a hundred, and in a few days they collect-
ed fourteen thousand. J
' I remember,' says Salisbury, c seeing, in a nur-
sery near Bagshot, several acres of young forest
trees, particularly larch, the roots of which were com-
pletely destroyed by it, so much so, that not a single
tree was left alive. ' We are doubtful, however,
whether this was the grub of the cockchafer, and
think it more likely to have been that of the green
rose beetle (Cetonia aurata), which feeds on the
roots of trees.
The grub of an allied genus, the midsummer
chafer (Zantheumia Solstilialis, LEACH), has for the
last two years been abundant on Lewisham Hill,
Blackheath, doing considerable injury to herbage
and garden plants. This beetle may be known from
being smaller and paler than the cockchafer, and
from its not appearing before midsummer. The grub
is very similar.
* Philosoph. Trans, xliv, 579. t Aniiru Biog. iii, 233.
$ Anderson's Recr. in Agricult. iii, 420. Hints, 74.
RAVAGES OF GRUBS. 229
The best way of preventing the ravages of these
insects would be to employ children to collect the
perfect insects when they first appear, before they lay
their eggs; but when a field is once overrun with
the larva, nothing can be done with it, except paring
and burning the surface, or ploughing it up, and
turning in a flock of ducks or other poultry, or a
drove of pigs, which are said to eat these grubs,
and to fatten on the fare. Drenching the field with
stable urine* by means of reservoir carts, like those
used for watering roads, would, if sufficiently done,
both kill the grubs, and beneficially manure the land.
The grub called the wire worm, though not very
appropriately, is the larva of one of the spring or
click beetles (Hemirhipus lineatus, and H. obscurus,
LATREILLE), known by their long flattish body, and
their power of springing with a clicking sound out
of the hand when caught. In some works on agri-
culture, the larva of a common crane fly (Tipula
oleracea or T. crocata) is called the wire worm, we
suppose by mistake. "\ The grubs of the click bee-
tles, just alluded to, are said by Bierscander J and
by Mr Paul of Starston, Norfolk , who watched
their transformations, to continue five years before
producing the perfect insect. During this time the
grub feeds chiefly on the roots of wheat, rye, oats,
barley, and grass; but seems also sometimes to attack
the larger roots of potatoes, carrots, and salads. Its
ravages are often so extensive as to cut off entire
crops of grain. It appears to be most partial to land
newly broken up; and has not been found so abun-
dant in meadows and pastures, unless in fields recently
laid down with grass. ' The wire worm,' says
Spence, c is particularly destructive for a few years
* See the Harleian Dairy System, p. 222.
t See Loudon's Encycl. of Agricult. 6921.
J Act. Holm. 1779, p. 284. Kirby and Spence, i, 182.
TOL. vi. 20
230
INSECT TRANSFORMATIONS.
in gardens recently converted from pasture ground.
In the botanic garden at Hull, thus circumstanced, a
great proportion of the annuals sown in 1813 were
destroyed by it. A very simple and effectual remedy,
in such cases, was mentioned to me by Sir Joseph
Banks. He recommended that slices of potatoes
stuck upon skewers, should be buried near the seeds
sown, examined every day, and the wire- worms,
which collect upon them in great numbers, de-
troy ed.'*
The wire worm is long, slender, and very tough
and hard ; but otherwise it has no resemblance to
wire, being whitish in colour, of a flattish form, and
jointed or ringed. Its breathing spiracles, two in
number, are on the back of its last ring.
a, Wire worm ; 6, Click beetle.
An insect of this family (Elater noctilucus, LINN.)
is exceedingly destructive, in the West Indies, to the
sugar-cane; the grub, according to Humboldt and
Bonpland, feeding on its roots and killing the
plants."]*
Instances are by no means rare, however, of in-
sects being accused of depredations of which they are
not guilty, from the mere circumstance of their being
* Intr. i, 182-3. t Geog. des Plantes, 136.
RAVAGES OF GRUBS. 231
found in abundance where ravages have been com-
mitted by others that have naturally disappeared It
is not improbable that this was the case with a grub
of some beetle (Staphylinidce!), mentioned by
Mr Walford, and mistaken by him for the wire
worm Out of fifty acres of wheat sown in 1802,
ten had been destroyed in October, by this grub
eating into the centre of the young stem an inch
below the surface and killing the plant.* It seems
still more probable that the grub of a native beetle
(Zabrus gibbus, STEPHENS), which has been found
in considerable numbers near Worthing, Brighton,
Hastings, and Cambridge, has been unjustly blamed
as a destroyer of corn; though we have the respect-
able authority of Germar, who, with other members
of the society of Natural History of Halle, ima-
gined he had ascertained the fact. In the spring of
1813, about two hundred and thirty acres of young
wheat are said to have been destroyed by it; and it
is farther supposed to be the same insect which
caused great destruction in Italy in 1776. This grub
is said to take probably three years in coming to a
beetle, in which state it is alleged to clamber up the
stems at night, to get at the corn. It is important
to remark, that along with these grubs were found
x
a, Zabrus glbbus ; 6, Melolontha ruficornis.
* Linn. Trans, ix, 156-61.
INSECT TRANSFORMATIONS.
those of a chafer (Melolontha ruficornis, FABR.), in
the proportion of about a fourth.*
To this account, Mr Stephens appends the shrewd
questions ' May not these herbivorous larva? [of the
chafer] have been the principal cause of mischief to
the wheat, while those of the Zabrus rather contri-
buted to lessen their numbers, than to destroy the
corn ? And is it not probable that the perfect insects
ascend the corn for the purpose of devouring the
insect parasites thereon? This is a subject,' he
justly adds, ' that requires investigation, as it is high-
ly important, for the interests of the agriculturist
in those districts where the insect abounds, that
the question should be thoroughly set at rest; be-
cause, should the Zabri depart from the habits of
the group to which they belong, and become herbi-
vorous instead of carnivorous, their destruction would
be desirable ; while, on the contrary, if they destroy
the devourers of our produce their preservation should
be attempted.'')"
We have little doubt that Mr Stephens is right,
and Gerrnar wrong ; but it would be improper to
decide the question by analogy unsupported by direct
experiment. One thing is certain, that both this
family (Harpalidce, MACLEAY) and the whole sec-
tion (Mephaga, CLAIRVILLE) are riot herbivorous,
but carnivorous.J Similar errors will corne under
our notice, as we proceed, not more defensible
than that of the old soldier causing caterpillars in
France.^
Even when agricultural produce escapes being
devoured at the root, or the young shoots eaten up,
the seeds are often made the prey of the grubs of
* Germar, Mag. der Entomol., i, 1-10 ; and Kirby and
Spence i, 169.
t Stephens, Illustrations, i, Mandib. pp. 4 and 140.
$ See an Illustration in Insect Architect., p. 207-8.
RAVAGES OF GRUBS. 233
beetles and weevils. Among the first, the gnawing
beetles (Bruchidcc, LEACH) are very destructive.
In North America, the pea beetle (Bruchus Pisi,
LINN.) commits such extensive depredations on
pulse, that in some districts the sowing of peas has
been abandoned as useless. Kalm, the Swedish
traveller, having witnessed these depredations in
America, became quite alarmed when he discovered
the insect among some peas he had brought to
Sweden, lest he should be the means of introducing
so formidable a pest.^ His fears seem to us to have
been in a great measure groundless ; for, probably,
the insect may be indigenous to Sweden, as it is to
Britain, though from circumstances of climate, and
other causes, it is seldom produced in such numbers
with us as to occasion extensive damage. It may have
been the same or an allied species of grub mentioned
by Amoroux as having spread an alarm in France in
1780, when the old fancy of its being poisonous
induced the public authorities to prohibit peas from
being sold in the markets. | The insect most
destructive to our peas is the pulse beetle (Bruchus
granariuSy LINN.), which sometimes lays an egg on
every pea in a pod, which the grub, when hatched,
destroys. In the same way > clover seed is often attacked
by two or more species of small weevil (Jlpion,
HERBST), known by the yellow colour of their
thighs or their feet; and when the farmer expects to
reap considerable profit, he finds nothing but empty
husks.
We have mentioned the ravages committed in
granaries by the caterpillars of small moths ; but
these are rivalled in the work of destruction by
several species of grubs. One of these grubs is
* Kalm's Travels, vol. i, p. 173.
t Amoroux, Insectes Venimeux, 288. Kirby and Spence,
i, 177.
VOL. VI. 20*
234 INSECT TRANSFORMATIONS.
called by the French cadelle ( Trogosita mauritamca,
OLIVIER), and is reported to have done more damage
to housed grain than any other insect.* The pest
of the granaries, which is but too well known in this
country, is the grain weevil (Calandra granaria,
CLAIRVILLE), the same, probably, which is mentioned
by Virgil,
Populatque ingentem farris acervum
Curculio. Georg. i, 87.
The high stacks of corn
Are wasted by the weevil. Trapp .
Kirby and Spence calculate that a single pair of
weevils may produce in one season 6000 descendants;
and they were told by an extensive brewer that he
had collected and destroyed them by bushels,"!"
meaning, no doubt, insects and damaged grain to
gether.
Corn weevil (Calandra grunaria), magnified.
Another beetle grub, popularly called the meal
worm, the larva of Tenebrio molitor, LINN., which
lives in that state two years, does no little damage to
flour, as well as to bread, cakes, biscuit, and similar
articles. Accounts are also given of the ravages com-
mitted by the grubs of other beetles, of several species
apparently not well ascertained, upon different sorts of
provisions, such as bacon, ham, dried tongues, ship
biscuit, &c. Sparrman tells us, that he has wit-
nessed the ground peas on ship-board so infested
* Olivier, ii, 19. t Intr. i, 173.
RAVAGES OF GRUBS, 235
with these grubs, that they were seen in every
spoonful of the soup. In the case of soup, or of other
food which has been exposed to heat, the only
inconvenience is the disgust which must ensue;
but, unfortunately, there may sometimes occur cir-
cumstances of a more serious nature, - from either
the eggs or the insects themselves being incautiously
swallowed alive. We do not wish, however, to
create, so much as to allay, the fears entertained by
those who are unacquainted with the habits of
insects; and nothing we are persuaded will do this
more effectually than a statement of facts well
ascertained. c Several people/ says the Abbe de la
Pluche, ' never eat fruit because they believe that
spiders and other insects scatter their eggs upon it
at random;'* but even if this were so, as it is not,
it. would be impossible for the young, should they be
hatched in the stomach, to live there for an instant.
The possible cases in which this may occur we shall
now briefly notice; they are fortunately very rare.
The meal worm, and some of the grubs which
feed on grain and other provisions, are recorded to
have been swallowed, and to have given rise to
disorders in the stomach and bowels ; but in all such
cases it is plain, that if the insects did survive
the increased temperature of the stomach, they
could only live on the food swallowed from time to
time, for, not being carnivorous, they would not attack
Meal worm, and the beetle produced from it.
* Spectacle de la Nature, i, 65.
236
INSECT TRANSFORMATIONS.
the stomach itself. The same remark will apply no
less forcibly to the herbivorous larvae, which might
chance to be swallowed in salad, &c. The cater-
pillar of the tabby moth (Jlglossa pinguinalis,
LATREILLE), which feeds on butter, the leather on
book-boards, &c, is said, on the authority of Lin-
naeus, to get sometimes into the stomach, and to
produce considerable disorder;* but this insect is
very common in houses,")" and, from the rarity of
such accidents, we are led to doubt the evidence
usually brought forward. In this case we are
the more induced to question the authority of Lin-
naeus, from his having made an evident mistake in a
similar case respecting intestinal worms.
Transformations of the tabby moth (A^lossapinguin':lis). a, the
caterpillar feeding on butter ; 6, c, d, feeding on leather under
galleriefe : e, the moth with the down rubbed off ; /, the same
perfect.
Linnaeus affirms, that in the presence of seven of
his companions he discovered, near Reuterholm, in
Dalecarlia, a tape worm in acidulous ochre ( Ockram
at which he marvelled the more since
* Linnaeus, quoted by Kirby and Spence, i, 136.
t Latreille, Hist. Geprrale, xiv, 229.
INTESTINAL WORMS. 237
acidulous water of this kind had been drank with
the design of expelling these worms. * This
account, however, proves too little; for, as Bonnet,
Reaumur, Pallas, and other eminent naturalists
remark, if such were the fact, we should find in-
testinal worms (so very numerous in most animals)
swarming in such places, and from their size
(Boerhaave saw one thirty- ells long) they could
not escape observation; whereas this was at that
time the only instance recorded of one found
out of the body. We are of opinion that Lin-
naeus must have been deceived by similarity of
form. A subsequent instance is recorded by Dr
Barry, of Cork, who imagined he had found the
origin of the common small thread worm (Oxyuris
vermicularis, BREMSER) in the water of a well the
aquatic only differing from the intestinal worms
in colour. But were all descriptions as loose as this
the grossest mistakes must ensue; for it is quite
clear that Dr Barry's aquatic worms were a very
common species (JVais\ and though similar in
external form, altogether different in internal
structure from the Oxyuridce of the intestines.
Were the latter, indeed, introduced into the body
from water, they would not only be found in this
particular well, two miles from Cork, but would
swarm in all the waters in the empire; since there
are few individuals who are not affected with these
worms at some period of their lives. According to
our experiments, the nai's ceases to exist in a tem-
perature considerably less than that of the human bo-
dy; besides, as it lives on minute fresh-water mollus-
cse, it could find no food in the intestines. t
The celebrated Dr J. P. Frank is no less mistaken
in referring us for the origin of intestinal worms to
f minute insects flying in the air;'J for, if so, the
* Linnaeus, quoted by Bonnet, GEuvres, iii, 137. t J.R.
Frank. De Curand. Homin. Morb. lib. vi.
238 INSECT TRANSFORMATIONS.
worms would naturally produce similar insects to
their parents; whereas they are either oviparous, as
Goetze affirms, or, as Bremser thinks, ovo-viparous;^
both agreeing that they are not transformed into
flying insects. Reaumur made the more plausible
conjecture, that they might be introduced by eating
tench and other fish, in which they are known to
abound;| but, independently of their being destroyed
by heat in cooking, this has been subsequently dis-
proved by experiment; for M. Deslonchamps says,
that 'when animals are fed for some time on in-
testinal worms (Entoozaria) alone, and then killed,
they are not found infested with these worms. 'J
Valisnieri and Hartsocker suppose, without a shadow
of proof, that worms are transmitted from parents
to children like other hereditary disorders; while
the late M. Lamarck refers their production to c the
march of nature in the production of all living
beings !' This indefinite doctrine is also held by
Geoffroi St Hilaire, Cuvier, Blumenbach, and other
distinguished living naturalists; but we think it more
philosophical and more manly, in such obscure cases,
at once to confess our ignorance of the ways of nature,
and to wait for further observation, than to frame idle
theories, supported only by vague analogies and doubt-
ful facts.
It may not be uninteresting to mention, however,
that upwards of 1200 species of intestinal worms
have been discovered; and probably there may be
twice as many more of whose existence nothing is
yet known. Sixteen of these species have been
found in the human body ; the rest are peculiar to
other animals. || Some of the more singular species.
* Bremser, Uber Lebende Wb'rmer in leb. Mensch,
t Letter to Bonnet, OEuvres, vol. iii, p. 344.
J Diet. Classique, vol. viii, p. 589-
$ Anim. sans Vertebres, vol. i, p. 15.
II Diet. Classique, vol. viii, p. 593.
INTESTINAL WORMS.
239
are here represented, from the splendid work of
Bremser.
Intestinal worms.
That insects are, in some rare cases, intro-
duced into the human stomach, has been more than
once proved ; though the greater number of the
accounts of such facts in medical books are too
inaccurate to be trusted.* But one extraordinary
case has been completely authenticated, both by me-
dical men and competent naturalists; and is pub-
lished in the Dublin Transactions, by Dr Pickells
of Cork. | Mary Riordan, aged 28, had been much
affected by the death of her mother, and at one of
her many visits to the grave seems to have partially
lost her senses, having been found lying there on
the morning of a winter's day, and having been ex-
posed to heavy rain during the night. When she
was about fifteen, two popular Catholic priests had
died, and she was told by some old women that if she
* See Good's Nosologia, Helminthia Alvi; and Study of Med.
vol. i, p. 336
t Trans, of Assoc. Phys. in Ireland, iv, vii, and v., p. 177,
8vo. Dublin, 1824 1828.
240 INSECT TRANSFORMATIONS.
would drink daily, for a certain time, a quantity of
water, mixed with clay taken from their graves, she
would be for ever secure from disease and sin. Fol-
lowing this absurd and disgusting prescription, she
took from time to time large quantities of the draught ;
some time afterwards, being affected with a burning
pain in the stomach (Cardialgia), she began to eat
large pieces of chalk, which she sometimes also mixed
with water and drank.
Now, whether in any or in all of these draughts she
swallowed the eggs of insects, cannot be affirmed ;
but for several years she continued to throw up incre-
dible numbers of grubs and maggots, chiefly of the
churchyard beetle (Blaps mortisaga, FABR.). * Of
the larvae of the beetle,' says Dr Pickells, ' 1 am
sure I considerably underrate, when I say that not
less than 700 have been thrown up from the stomach
at different times since the commencement of my
attendance. A great proportion were destroyed by
herself to avoid publicity; many, too, escaped im-
mediately by running into holes in the^ floor. Up-
wards of ninety were submitted to Dr Thomson's *
examination; nearly all of which, including two of the
specimens of the meal worm (Tenebrio m-olitor), I
saw myself, thrown up at different times. The aver-
age size was about an inch and a half in length, and
four lines and a half in girth. The larvre of the dip-
terous insect, though voided only about seven or eight
times, according to her account ; came up almost
literally in myriads. They were alive and moving.' 1
Altogether, Dr Pickells saw nearly 2000 grubs of
the beetle, and there were many which he did not
see. Mr Clear, an intelligent entomologist of Cork,
kept some of them alive for more than twelve months.
Mr S. Cooper cannot understand whence the con-
tinued supply of the grubs was provided, seeing that
* The well-known author of' Zoological Researches/ &e.
INTESTINAL GRUBS AND BEETLES. 241
larvae do not propagate, and that only one pupa and
one perfect insect were voided;* but the simple fact
that most beetles live several years in the state of
larvae sufficiently accounts for this. Their existing and
thriving in the stomach, too, will appear less wonder-
ful from the fact that it is exceedingly difficult to kill
this insect; for Mr Henry Baker repeatedly plunged
one into spirit of wine, so fatal to most insects, but it
revived, even after being immersed a whole night, and
afterwards lived three years. "f
Churchyard beetle (Blaps mortisagct), in the grub and perfect state,
from the figures of Dr Pickells.
That there was no deception on the part of the
woman, is proved by the fact that she was always
anxious to conceal the circumstance; and that it was
only by accident that the medical gentlemen, Drs
Pickells, Herrick, and Thomson, discovered it. More-
over, it does riot appear that, though poor, she ever
took advantage of it to extort money. It is interest-
* Cooper's edition of Good's Study of Medicine, i, 358*
Philosoph. Trans., No. 457,
VOL. vi. 2!
242 INSECT TRANSFORMATIONS.
ing to learn that by means of turpentine, in large
doses, she was at length cured.
The grub of the nut weevil (Balaninus Nucum,
GERMAK) might, perhaps, by rare accident, get into
the stomach, either of man or of the quadrupeds
which feed on nuts; but as it is by no means so
tenacious of life as the grub of the churchyard beetle
(Blaps mortisaga) above described, it is unlikely-
that it would produce any considerable disorder.
The weevil in question, like the rest of its congeners,
is furnished with an instrument for depositing its
eggs considerably different from those of the ichneu-
mons and saw-flies. For this purpose the weevil
makes use of its long horny beak (Rostrum) to drill
a hole in filberts and hazel nuts, while in their young
and soft state, about the beginning of August. The
mother weevil may then be seen eagerly running
over the bushes, and it would appear that she always
rejects the nuts in which one of her neighbours may
have previously laid an egg; at least we never .find
two grubs in the same nut. The egg, which is thus
thrust into the young nut, is of a brown colour, and
is hatched in about a fortnight, the grub feeding on
the interior of the shell as well as the soft pulp, till
the one becomes too hard and the other too dry to be
nutritive. It is remarkable that, during this period,
he takes care not to injure the kernel, but permits it
to ripen before he attacks it. Had he done this pre-
maturely, he would have ultimately been starved, as
he has not the power of perforating another nut
when the first is consumed. It is said also that he
is very careful to preserve the original hole made by
the mother, by gnawing around its inner edges, in
order to facilitate his exit/ which he effects when the
* Bingley, Animal Biography, vol. viii, p. 251.
GRUBS OF WEEVILS.
243
nut falls to the ground in September or October.
The hole found in the nut appears much too small
to have admitted of its passage ; but from being very
soft it no doubt stretches itself out for the purpose,
usinp; its short claws as instruments of motion.
Rosel, in order to observe the transformation of
these nut grubs, put a number of them, at the com-
mencement of winter, into glasses half filled with
earth, covered with green turf. All of them dug
directly down into the earth, remained there all
the winter, and did not change into pupae till the fol-
lowing June ; the perfect weevils appeared from the
1st till about the 20th of August, but still kept under
ground for the first week after their change.
Nut and apple-tree beetles. A, a branch of the filbert-tree
a, egg hole in the nut ; 6, exit hole of the grub. B, the larvse of
the nut beetle. C, the same in the pupa btate. D, female beetle.
E, male beetle, c, the beetle that destroys the bloom-bud of the
apple tree-, a, the same in the larva state; 6, the chrysalis of
the same.
c During the autumn,' says Salisbury, ' we fre-
quently observe a small red weevil busily employed
in traversing the branches of apple-trees, on which
it lays its eggs by perforating the bloom buds. In
the spring, these hatch, and the grubs feed on the
244 INSECT TRANSFORMATIONS.
petals of the flowers, drawing up the whole flower
into a cluster by means of their web. The bloom
thus becomes destroyed, and the grub falls to the
ground, where it lays itself up in the chrysalide state ;
and in the autumn afterwards we find the weevil
renewed, which again perforates the buds, and causes
a similar destruction in the following spring. Mr
Knight, in his treatise on the apple, mentions a beetle
which commits great destruction on the apple-trees in
Herefordshire; but I do not think it the same as the
one I have described above, and which is very common
in the gardens near London.'* Salisbury's weevil
is probably the Jlnthonomus Pomorum of Germar;
and Knight's, his Poiydrusus Mali. Another weevil
(Rhijnchites Bacchus, HERBST), one of our most
splendid but not very common native insects, bores
into the stone of the cherry, &c, while it is young
and soft, and deposits an egg there, as the nut weevil
does in the nut.
* Perhaps the most voracious grub on record is that
of a large and beautiful beetle (Calosoma syco-
phanta, WEBER), which is rare in Britain. It is
sometimes found in the nests of the processionary and
other gregarious caterpillars, so gorged with those it
has devoured that it can scarcely move without
bursting. JN"ot contented with this prey alone, how-
ever, the younger grubs are said c often to take ad-
vantage of the helpless inactivity into which the glut-
tony of their maturer comrades has thrown them,
and from mere wantonness, it should seem, when in
no need of other food, pierce and devour them.'f It
is a familiar occurrence to those who breed insects to
find caterpillars, whose natural food is leaves, devour-
ing others in the same nurse-box; and without any
* Salisbury's Hints on Orchards, p. 92.
t Kirby and Spence, vol. i, p. 277.
GRUBS OF BEETLES. 245
apparent discrimination whether these are the progeny
of their own mother, or of a different species.*
We have frequently observed a very remarkable
instinct in the grubs of a species of beetle ( Scolytus
Destructor, GEOFFROY), which lives under the dead
bark of trees. The mother insect, as is usual with
beetles, deposits her eggs in a patch or cluster in a
chink or hole in the bark; and when the brood is
hatched, they begin feeding on the bark which had
formed their cradle. There is. of course, nothing won-
derful in their eating the food selected by their mother;
but it appears that, like the caterpillars of the clothes
moth, and the tent insects, they cannot feed except un-
der cover. They dig, therefore, long tubular galleries
between the bark and the wood; and, in order not
to interfere with the runs of their brethren, they
branch off from the place of hatching like rays from
the centre of a circle: though these are not al-
ways in a right line, yet, however near they may ap-
proach to the contiguous ones, none of them ever
Bark mined in rays by beetle grubs.
* J. R. See also De Geer, i, 533, &c, apd R aumur, ii, 413,
VOL, vi. 21*
INSECT TRANSFORMATIONS.
break into each other's premises. We cannot but ad-
mire the remarkable instinct implanted in those grubs
by their Creator; which guides them thus in lines di-
verging farther and farther as they increase in size,
so that they are prevented from interfering with the
comforts of one another.
The various instances of voracity which we have
thus described sink into insignificance, when com-
pared with the terrible devastation produced by the
larvaB of the locust (Locusta migraloria, LEACH),
the scourge of oriental countries. ' A fire de-
voureth before them,' says the Prophet Joel, c and
behind them a flame burneth: the land is as the
garden of Eden before them, and behind them a
desolate wilderness; yea, and nothing shall escape
them. The sound of their wings is as the sound of
chariots, of many horses running to battle; on the
tops of mountains shall they leap, like the noise of a
flame of fire that devoureth the stubble, as a strong
people set in battle-array. Before their faces, the
people shall be much pained, all faces shall gather
blackness. They shall run like mighty men; they
shall climb the wall like men of war; and they shall
march every one in his ways, and they shall not break
their ranks; neither shall one thrust another.'*
The intelligent traveller, Dr Shaw, was an eye-
witness of their devastations in Barbary in 1724,
where they first appeared about the end of March,
their numbers increasing so much in the beginning
of April as literally to darken the sun; but by the
middle of May they began to disappear, retiring into
the Mettijiah and other adjacent plains to depo-
sit their eggs. These were no sooner hatched
in June,' he continues, c than each of the broods
collected itself into a compact body, of a furlong or
more in square; and marching afterwards directly
* Joel ii, 2, &c.
RAVAGES OF LOCUSTS. 247
forwards toward the sea, they let nothing escape
them, they kept their ranks like men of war; climb-
ing over, as they advanced, every tree or wall that
was in their way; nay, they entered into our very
houses and bed-chambers, like so many thieves.
The inhabitants, to stop their progress, formed
trenchers all over their fields and gardens, which they
filled with water. Some placed large quantities of
heath, stubble, and other combustible matter, in rows,
and set them on fire on the approach of the locusts;
but this was all to no purpose, for the trenches were
quickly filled up, and the fires put out, by immense
swarms that succeeded each other.
c A day or two after one of these hordes was
in motion, others were already hatched to march and
glean after them. Having lived near a month in this
manner, they arrived at their full growth, and threw
off their nympha-state by casting their outward skin.
To prepare themselves for this change, they clung
by their hinder feet to some bush, twig, or corner of
a stone; and immediately, by using an undulating
motion, their heads would first break out, and then
the rest of their bodies. The whole transformation
was performed in seven or eight minutes; after which
they lay for a small time in a torpid, and, seemingly,
in a languishing condition; but as soon as the sun
and the air had hardened their wings by drying up the
moisture that remained upon them after casting their
sloughs, they resumed their former voracity, with an
addition of strength and agility. Yet they continued
not long in this state before they were entirely disper-
sed.'*
It is difficult to form an adequate conception of
the swarms of locusts which, in 1797, invaded
the interior of southern Africa, as recorded by Mr
Barrow, In the part of the country where he was,
* Shaw'a Travels, p. 287.
248 INSECT TRANSFORMATIONS.
the whole surface of the ground, for an area of
nearly two thousand square miles, might literally be
said to be covered with them. The water of a very
wide river was scarcely visible, on account of the dead
carcases of locusts that floated on the surface, drowned
in the attempt to come at the reeds that grew in it.
They had devoured every blade of grass, and every
green herb, except the reeds. But they are not pre-
cisely without a choice in their food. When they at-
tack a field of corn just come into ear, they first, ac-
cording to Mr Barrow, mount to the summit and
pick out every grain before they touch the leaves and
stem, keeping the while constantly in motion, with the
same intent of destruction always in view. When the
larvae, which are much more voracious than the perfect
insects, are on a inarch during the -day, it is utterly
impossible to turn the direction of the troop, and this
seems usually to correspond with that of the wind.
Towards the setting of the sun the march is discon-
tinued, when the troop divides into companies that sur-
round the small shrubs, or tufts of grass, or ant-
hills, in such thick patches, that they appear like so
many swarms of bees; and in this manner they rest till
day-light. At these times it is that the farmers have
any chance of destroying them; this they sometimes
effect by driving among them a flock of two or three
thousand sheep; by whose restlessness great numbers
of them are trampled to death. The year 1797 was
the third of their continuance inSneuwberg; and their
increase had been more than a million-fold from year
to year.
This district, however, had been entirely free from
them for ten years preceding their visit in 1794.
Their former exit was singular: all the full grown
insects were driven into the sea by a tempestuous
north-west wind, and were afterwards cast up on the
beach, where they formed a bank of three or four feet
RAVAGES OF LOCUSTS. 249
high, and extending to a distance of nearly fifty miles.
When this mass became putrid, and the wind was at
south-east, the stench was sensibly felt in several parts
of Sneuwberg, although distant at least a hundred
and fifty miles.*
Pallas gives a more detailed account of the daily
proceedings of the larvae of the Italian locust (Lo-
custa Italica, LEACH). ' In serene weather,' he
tells us, ( the locusts are in full motion in the morn-
ing, immediately after the evaporation of the dew;
and if no dew has fallen, they appear as soon as the
sun imparts his genial warmth. At first, some are
seen running about like messengers among the re-
posing swarms, which are lying partly compressed
upon the ground at the side of small eminences, and
partly attached to tall plants and shrubs. Shortly
after the whole body begins to move forward in one
direction, and with little deviation. They resemble a
swarm of ants, all taking the same course, at small
distances, but without touching each other: they uni-
formly travel towards a certain region as fast as a fly
can run, and without leaping, unless pursued; in
which case, indeed, they disperse, but soon collect
again and follow their former route. In this manner
they advance from morning to evening without halt-
ing, frequently at the rate of a hundred fathoms, and
upwards, in the course of a day. Although they pre-
fer marching along high roads, foot-paths, or open '
tracts, yet, when their progress is opposed by bushes,
hedges, and ditches, they penetrate through them:
their way can only be impeded by the waters of
brooks or canals, as they are apparently terrified at
every kind of moisture. Often, however, they en-
deavour to gain the opposite bank, with the aid of
overhanging boughs; and, if the stalks of plants or
shrubs be laid across the water, they pass in close
* Barrow's Travels in South Africa, p. 257.
250 INSECT TRANSFORMATIONS.
columns over these temporary bridges, on which they
even seem to rest, and enjoy the refreshing coolness.
Towards sun-set, the whole swarm gradually collect
in parties, and creep up the plants, or encamp on
slight eminences. On cold, cloudy, or rainy days,
they do not travel. As soon as they acquire wings,
they progressively disperse, but still fly about in large
swarms. '*
When Captains Irby and Mangles were travelling
round the southern extremity of the Dead Sea, in the
end of May, they had an opportunity of observing
these insect depredators. ' In the morning,' say
they, ' we quitted Shobek. On our way we passed a
swarm of locusts that were resting themselves in a
gully; they were in sufficient numbers to alter ap-
parently the colour of the rock on which they had
alighted, and to make a sort of crackling noise while
eating, which we heard before we reached them.
Volney compares it to the foraging of an army. Our
conductors told us they were on their way to Gaza,
and that they pass almost annually. 7 ")"
Even our own island has been alarmed by the ap-
pearance of locusts, a considerable number having
visited us in 1748; but they happily perished without
propagating. Other parts of Europe have not been
so fortunate. In 1650 a cloud of locusts were seen
to enter Russia in three different places; and they
afterwards spread themselves over Poland and Li-
thuania in such astonishing multitudes, that the air was
darkened, and the earth covered with their num-
bers. In some places they were seen lying dead,
heaped upon each other to the depth of four feet; in
others they covered the surface of the ground like a
black cloth : the trees bent with their weight, and the
* Travels in Russia, ii, 422-6.
t Irby and Mangles' Travels in Egypt and Syria, p. 443.
RAVAGES OF LOCUSTS.
251
damage the country sustained exceeded computation,*
They have frequently come also from Africa into
Italy and Spain. In the year 591 an infinite army
of locusts, of a size unusually large, ravaged a con-
siderable part of Italy, and being at last cast into the
sea, (as seems foj the most part to be their fate,)
a pestilence, it is alleged, arose from their stench,
which carried off nearly a million of men and beasts.
In the Venetian territory, likewise, in 1478, more
than 30,000 persons are said to have perished in a
famine chiefly occasioned by the depredations of
locusts.*)"
* Bingley, Anim. Biog., iii, 280.
t Mouffet, Theatr. Insect., 123.
Locust.
CHAPTER X.
Voracity of Caterpillars, Grubs, and Maggots ; concluded.
MAGGOTS.
ADHERING to the distinction of terming those larvae
which are destitute of feet, maggots, we shall notice
here a very destructive one, which is sometimes popu-
larly called the grub, and sometimes confounded with
the wire worm.* We allude to the larvae of one or two
common species of crane flies (Tipulidce], well known
by the provincial names of father-long-legs, Jeriny-
spinners, and tailors. These insects are so common
in some meadows, that, being very shy and fearful of
danger, they rise in swarms at every step some of
them flying high, others only skipping over the grass,
and others running and using their long legs as the
inhabitants of marshy countries use stilts, and em-
ploying their wings like the ostrich to aid their limbs.
These flies deposit their eggs in the earth; some-
times in grass fields or moist meadows, and some-
times in the tilled ground of gardens and farms.
For this purpose the female is provided with an ovi-
positor well adapted to the operation, consisting of a
sort of pincers or forceps of a horny consistence, and
sharp at the point. By pressure, as Reaumur says,
the eggs may be extruded from this in the same way
as the stone can be easily squeezed out of a ripe
cherry as in the following figure.
* See Stickney's Observ. on the grub, 8vo. Hull, 1800.
MAGGOTS OP CRANE FLIES. 253
Ovipositor and eggs of the crane fly (Tipula).
The eggs are exceedingly small and black, like
grains of gunpowder, and each female lays a good
many hundreds. The position which she assumes
appears somewhat awkward, for she raises herself
perpendicularly on her two hind legs, using her ovi-
positor as a point of support, and resting with her
fore-legs upon the contiguous herbage. She then
thrusts her ovipositor into the ground as far as
the first ring of her body, and leaves one or more
eggs in the hole; and next moves onwards to ano-
ther place, but without bringing herself into a hori-
zontal position. The maggot, when hatched from
the egg, immediately attacks the roots of the grass
and other herbage which it finds nearest to it; and
of course the portion of the plant above ground
withers for lack of nourishment.
The maggots of this family which seem to do most
injury are those of Tipula oleracea and T. cornicina.
In the summer of 1828, we observed more than an
acre of ground, adjoining the Bishop of Oxford's
garden, at Blackheath, as entirely stripped, both of
grass and every thing green, as if the turf had been
VOL. vi. 22
254
INSECT TRANSFORMATIONS.
Crane fiy ovipositing, and the larva beneath, in the earth, feeding
upon grass roots.
pared off from the surface, the only plant untouched
being the tiny bird tare (Ornithopus perpusillus).
On digging here to learn the cause, we found these
larvae already full-fed, and about to pass into pupae,
after having left nothing upon which they could subsist.
It was not a little remarkable that they seemed to be
altogether confined to this spot; for we did not meet
with a single foot of turf destroyed by them in any
other part of the heath, or in the adjacent fields. So
RAVAGES OF MAGGOTS, 255
very complete, however, was their destruction of the
roots on the spot in question, that even now, at the
distance of two years, it is still visibly thinner of
herbage than the parts around it.*
Reaumur gives a similar account of their ravages
in Poitou, where, in certain seasons, the grass of the
low moist meadows has been so parched up in conse-
quence, as not to afford sufficient provender for the
cattle. He describes the soil in Poitou as a black
peat mould; and it was the same in which we found
them at Blackheath, with this difference, that the spot
was elevated and dry. According to M. Reaumur, also,
their only food is this sort of black mould, and not the
roots of grass and herbage, which he thinks are only
loosened by their burrowing.')" This view of the matter
appears strongly corroborated by the fact that several
species of the family feed upon the mould in the holes
of decaying trees, particularly the larva of a very
beautiful one s (Ctenophora flaveolata, MEIGJEN),
which is very rare in Britian. It is proper to men-
tion, however, that Mr Stickney's experiments, J
contrary to the conclusions of Reaumur, indicate
that these larvae devour the roots of grass; and Stew-
art says they feed on the roots of plants, corn, and
grasses, and are thence destructive to gardens, fields,
and meadows. They prevailed in the neighbourhood
of Edinburgh, and other places in Scotland, in the
spring of 1800, when they laid waste whole fields of
oats and other grain. '
In many districts of England these insects cut off
a large proportion of the wheat crop, particularly, it
would appear, when it had been sown on clover leys.
' In the rich district,' say Kirby and Spence, ' of
Sunk Island, in Holderness, in the spring of 1813,
hundreds of acres of pasture have been entirely de- ,
* J. R. t R aumur, v. 12, &c.
t Obs. on the Grub. Elements, ii, 267.
256 INSECT TRANSFORMATIONS.
stroyed by them, being rendered as completely brown
as if they had suffered a three month's drought, and
destitute of all vegetation except a few thistles. A
square foot of the dead turf being dug up, 2lO grubs
were counted on it; and, what furnishes a striking
proof of the prolific powers of those insects, last year
it was difficult to find a single one.'*
It is worthy of remark that the mandibles of these
destructive creatures, which are claw-shaped and
transverse, do not act against each other as is usual
among insects, but against two other pieces which are
immoveable, convex, and toothed, as if the under-
jaw in quadrupeds were divided into two, and should
act vertically on the two portions of the immoveable
upper-jaw thrown in between them.
The maggot of a minute fly of the same family,
known by the name of the wheat fly ( Cecido-
myia Tritici, KIRBY), is frequently productive of
great damage in the crops of wheat. Its history was
first investigated by Marsham, and subsequently by
Kirby, and several other intelligent naturalists. The
parent fly is very small, not unlike a midge ( Culicoi-
des punctata, LATH.), of an orange colour, and wings
rounded at the tip, and fringed with hairs. f The
female is furnished with a retractile ovipositor, four
times as long as the body, and as fine as a hair, for
depositing her eggs, which she does in the glumes
of the florets of the grain. The following account of
its proceedings is given by Mr Shireff, an intelli-
gent farmer of East Lothian.
* Wheat-flies,' he says, ' were first observed here
this season on the evening of the 21st of June, and,
from the vast number seen, it is probable a few of
them may have been in existence some days previous.
* Intr. i, 318, note,
t Linn. Trans., iii, 234 iv, 243-240; v. 96.
RAVAGES OF MAGGOTS. 257
The eggs were visible on the 23d, the larvae on the
30th of that month, and the pupae on the 29th of
July, The flies were observed depositing eggs on
the 28th, and finally disappeared on the 30th July;
thus having existed throughout a period of thirty-nine
days.
4 The flies were observed to frequent the wheat-
plant, including the thick-rooted couch-grass ( Triti-
cuin repens). They generally reposed on the lower
parts of the stems during the day, and became active
about sunset, except when the wind was high. I
have, however, seen them flying about on cloudy
mornings, till seven o'clock; and, upon one occasion,
witnessed them depositing .their eggs, in a shaded
situation, at two in the afternoon. Their movements
appear to be influenced by the rays of light, of which
they seem impatient, being active when the sun is
below or near the horizon; they frequent the most
umbrageous part of the crop, and shun that which is
deficient in foliage.
' The flies almost invariably preferred the ears
emerging from the vagina to those farther advanced,
for depositing their eggs on; and as one side only
of the ear is exposed when the plant is in this stage
of growth, the other side generally remained unin-
jured. The fly deserted the fields as the crop ad-
vanced towards maturity, and were found longest
on the spring-sown portion of the crop. It seemed
to feed on the gum adhering to the newly emerged
ears; and as there is a great diversity in the time of
sowing wheat in this neighbourhood, and conse-
quently of the ears escaping from the vagina, I
attribute the unusual length of time it has existed
this season, to the supply of food thus gradually fur-
nished.
i The fly deposits its eggs with much intensity,
and may easily be taken when so employed. Upon
.VOL. vi. 22*
258 INSECT TRANSFORMATIONS.
one occasion, I numbered thirty -five flies on a single
ear; and, after, carrying it a distance of a quarter of
a mile, six of them still continued to deposite eggs.
At another time, I placed a fly, then laying, between
the face and glass of my watch, where it deposited
several eggs, although invariably interrupted by the
revolution of the moment hand.
c The eggs of the fly are generally found in clus-
ters, varying in number from two to ten, upon the
inner chafF, in which the furrowed side of the grain is
embedded, and are also occasionally to be seen in
the interior parts of the flower and chaff. The eggs
are deposited by means of a long slender tube, and
fixed with a glutinous substance possessed by the fly.
A thread of glutinous matter frequently connects a
cluster of eggs with the style, where the larvae seem
to subsist on the pollen; in one instance, fifteen eggs
were numbered on such a thread, several of which
were suspended on the portion extending between
the chaff and the style. The fly not only seems thus
to provide a convevance from the larvae to the style,
but also food for their support. The anthers are pre-
vented from leaving the style in consequence of being
gummed down by the glutinous matter of the fly, and
the pollen thereby detained for the use of the larvae,
which otherwise would, in part, be carried out of the
glumes by the expansion of the filaments, known to
farmers by the term bloom. In the exertion of gum-
ming down the anthers, many of the flies are entan-
gled in the vascules of the corolla, and thus become a
sacrifice to their maternal affection.
' The larvae are produced from the eggs in the
course of eight or ten days: they are at first perfectly
transparent, and assume a yellow colour a few days
afterwards. They travel not from one floret to an-
other, and forty-seven have been numbered in one.
Occasionally there are found in the same floret larvae
RAVAGES OF MAGGOTS.
259
and a grain, which is generally shrivelled, as if depri-
ved of nourishment; and although the pollen may fur-
nish the larvae with food in the first instance, they
soon crowd around the lower part of the germen, and
there, in all probability, subsist on the matter destined
to have formed the grain. '*
Germination of a grain of wheat. , the heat t of the grain,
the part devoured by the insect, fe, bag o the s^ed. c, the root.
d, vessels to convey the nutriment for the root, e, feathers
conveying the pollen to fructify the seed.
Another intelligent observer, Mr Gorrie, of Annat
Gardens, Perthshire, found that by the first of August
all the maggots leave the ears, and go into the ground
about the depth of half an inch, where it is probable
they pass the winter in the pupa state. 't
It is interesting to learn that this destructive in-
* Loudon's Mag. of Nat., Hist., Nov. 1829. p: 450.
t Ibid, September, 1829, p. 324.
260 INSECT TRANSFORMATIONS.
Transformations of the wheat fly. a, the female fiy magnified ;
6, larvae, natural size, feeding; c, one magnified.
sect is providentially prevented from multiplying so
numerously as it might otherwise do, by at least two
species of ichneumons, which deposit their eggs in the
larvae. One of these (Encyrtus inserens, LATR.) is
very small, black, and shining. The other (Platy-
gaster Tipulce, LATR.) is also black, with red feet, and a
blunt tail. These have been frequently mistaken for
the wheat-fly; but as it has only iwo wings, while they
have four, the distinction is obvious. In order to
observe the proceedings of the ichneumons, Kirby
placed a number of the larvae of the wheat-fly on a
sheet of white' paper, and set a female ichneumon in
the midst of them. She soon pounced upon her vic-
tim, and intensely vibrating her antennae, and bending
herself obliquely, plunged her ovipositor into the body
of the larva, depositing in it a single egg. She then
passed to a second, and proceeded in the same man-
ner, depositing a single egg in each. Nay, when
she examined one which she found had already been
pricked, she always rejected it and passed to another.*
Mr ShirefF repeated these experiments successfully,
except that he saw an ichneumon twice prick the
same maggot, which * writhed in seeming agony,'
and ' it was again stung three times by the same
fly.' He adds, ' the earwig also destroys the larvae,
three of which I successfully presented to an earwig,
which devoured them immediately. '| Mr Gorrie
describes these ichneumons as appearing in myriads
* Linn. Trans, ut supra. t London's Mag. ut supra.
WHEAT FLIES 261
on the outside of the ear; but as impatient of bright
light, sheltering themselves from the sun's rays
among the husks.
Our English naturalists were for many years of
opinion, that the insect called the Hessian-fly, so
destructive to wheat crops in America, belonged to
the same family (Muscidce) with the common house-
fly; and Mr Mark wick, an intelligent naturalist, by
a series of observations on a British fly (Chlorops
pumilionis, MEIGEJN) which attacks the stems of
wheat, created no little alarm among agriculturists.
Mark wick 'a fly is less than a fourth of an inch in-
length, with dark shoulders striped with two yellow
lines, and the maggot is white. He planted roots of
wheat containing larvas in a small flower pot, and
covered them with gauze. Each stem produced one
of the above flies. The crop of wheat attacked by
this maggot, though at first it appeared to fail,
turned out well in consequence of numerous side
shoots. It is only the early wheat sown in October
that is affected by it.*
, The Hessian fly (Cccidomyia d'strurtor); 5, Markwick fly
((. htoreps fmmilionii,} magnified.
It now appears that Markwick was altoget her
mistaken in identifying his insect with the Hessian
fly (Cecidomyia destructor, SAY), which has been
accurately described by Mr Say in the ' Journal of
the Academy of Natural Sciences of Philadelphia'
* Mag. Nat. Hist. July 1829, p. 292.
INSECT TRANSFORMATIONS.
for 1817. It is a little larger than our wheat-fly,
more slender in the body, has longer legs, and is
not orange, but black and fulvous. The female
deposits from one to eight or more eggs on a single
plant of wheat, between the sheath of the inner leaf
and the stem nearest the roots ; in which situation,
with its head towards the root or first joint, the
young larva passes the winter, eating into the stem,
and causing it to break. *
The devastation committed by the Hessian fly
seems to have been first observed in 1776, and it
was erroneously supposed that the insect was con-
veyed among straw by the Hessian troops from Ger-
many. It was first noticed in the wheat fields of
Long Island, from which it spread gradually at the
rate of fifteen or twenty miles round; and in 1789 it
had advanced two hundred miles from its original
station in Long Island. Other accounts state that it
did riot travel more than seven miles annually, and
did little serious damage before 1788. Their num-
bers seem almost incredible. The houses in the
infested districts swarmed with them to so great a
degree, that every vessel was filled with them; five
hundred were actually counted on a glass tumbler
which had been set down for a few minutes with a
little beer in it. They were observed crossing the
Delaware river like a cloud; and even mountains do
not seem to interrupt their progress.! We can well
understand, therefore, that so formidable a ravager
should have caused a very great alarm; and even our
own government was in fear lest the insect should be
imported. The privy council, indeed, sat day after
day in deep consultation what measures should be
adopted to ward off the danger of a calamity more to
be dreaded, as they well knew, than the plague or
the pestilence. Expresses were sent off in all direc-
* Mag. Nat. Hist, vol. i, p. 228.
t Kirby and Spence, vol. i, p. 172.
CHEESE FLY. 263
tions to the officers of the customs at the different out-
ports respecting the examination of cargoes, de-
spatches were written to the ambassadors in France,
Austria, Prussia, and America, to gain information,
and so important altogether was the business deemed,
that the minutes of council, and the documents col-
lected from all quarters, fill upwards of two hundred
pages.*
As in the case of the English wheat-fly, the Ame-
rican Hessian fly has a formidable enemy in a
minute four-winged fly (Ceraphron destructor, SAY),
which deposits its eggs in the larvae. Were it not
for the Ceraphron, indeed, Mr Say is of opinion that
the crops of wheat would be totally annihilated in
the districts where the Hessian fly prevails. *f
Those who have, from popular associations, been
accustomed to look with disgust at the little white
larvae common in cheese, well known under the name
of hoppers, will be somewhat surprised to hear the
illustrious Swammerdam say,/ I can take upon me
to affirm, that the limbs and other parts of this
maggot are so uncommon and elegant, and con-
trived with so much art and design, that it is impos-
sible not to acknowledge them to be the work of infi-
nite power and wisdom, from which nothing is hid,
and to which nothing is impossible. J' But who-
ever will examine it with care, will find that Swam-
merdam has not exaggerated the facts.
The cheese-fly (Piophila Casei, FALLEN) is very
small and black, with whitish wings, margined with
black. It was one of those experimented upon by
Redi to prove that insects, in the fabric of which so
much art, order, contrivance, and wisdom appear,
* Young, Annals of Agric., vol. xi.
f Journ. of A cad. Philadelph. ut supra.
t Bibl. Naturae, vol. ii, p. 63.
264 INSECT TRANSFORMATIONS.
could not be the production of chance or rottenness,
but the work of the same Omnipotent hand which
created the heavens and the earth. This tiny little
fly is accordingly furnished with an admirable instru-
ment for depositing its eggs, in an ovipositor, which
it can thrust out and extend to a great length, so
that it can penetrate to a considerable depth into the
cracks of cheese, where it lays its eggs, 256 in
number. 4 I have seen them myself,' says Swam-
merdam, c thrust out their tails for this purpose to an
amazing length, and by that method bury the eggs
in the deepest cavities. I found in a few days after-
wards a number of maggots which had sprung from
those eggs, perfectly resembling those of the first
brood that had produced the mother fly. I cannot
but also take notice that the rottenness of cheese is
really caused by these maggots; for they both crum-
ble the substance of it into small particles and also
moisten it with some sort of liquid, so that the
decayed part rapidly spreads. I once observed a
cheese which I had puvposely exposed to this kind of
fly grow moist in a short time in those parts of it
where eggs had been deposited, and had afterwards
been hatched into maggots; though, before, the
cheese was perfectly sound arid entire.'*
The cheese-hopper is furnished with two horny
claw-shaped mandibles, which it uses both for dig-
ging into the cheese and for moving itself, being
destitute of feet. Its powers of leaping have been
observed by every one; and Swammerdam says, ' I
have seen one, whose length did not exceed the
fourth of an inch, leap out of a box six inches deep,
that is, twenty-four times the length of its own
body: others leap a great deal higher. 'f For this
purpose it first erects itself on its tail, which is fur-
nished with two wart-like projections, to enable it to
* Swammerdam, vol. ii, p. 69. t Bibl. Nat., vol. ii, p. 65.
CHEESE MAGGOTS.
265
maintain its balance. It then bends itself into a
circle, catches the skin near its tail with its hooked
mandibles, and after strongly contracting itself from
a circular into an oblong form, it throws itself with a
jerk into a straight line, and thus makes the leap.
Cheese hoppers (PiophUa casei, Fallen), a, the maggot ex-
tended ; , in a leaping position ; rf, the same magnified ; e, the
fly magnified ; y, g-, the fly, natural size. /
One very surprising provision is remarkable in
the breathing-tubes of the cheese maggot, which are
not placed, as in caterpillars, along the sides, but a
pair near the head and another pair near the tail.
Now, when burrowing in the moist cheese, these
would be apt to be obstructed; but to prevent this,
it has the power of bringing over the front pair a
fold of the skin, breathing in the meanwhile through'
the under pair. Well may Swammerdam denomi-
nate these contrivances ' surprising miracles of God's
power and wisdom in this abject creature.'
Like the other destructive insects above mentioned,
the multiplication of the cheese fly is checked by some
insect, whose history, so far as we are aware, is not
yet known. Swammerdam found many of the maggots
with other larvae in their bodies; but he did not trace
their transformations. If they were the larvae of an
ichneumon, it must be exceedingly minute.
It must have attracted the attention of the most
VOL. vi. 23
26$ INSECT TRANSFORMATIONS.
incurious, to see, during the summer, swarms of flies
crowding about the droppings of cattle, so as almost
to conceal the nuisance, and presenting instead a dis-
play of their shining corslets and twinkling wings.
The object of all this busy bustle is to deposit their
eggs where their progeny may find abundant food ;
and the final cause is obviously both to remove the
nuisance and to provide abundant food for birds
and other animals, which prey upon flies or their larva?.
The same remarks apply with no less force to the
blow-flies which deposit their eggs, and in some cases
their young, upon carcases. The common house-fly
(Musca domtstica) belongs to the first division, the
natural food of its larvae being horse-dung; conse-
quently it is always most abundant in houses in the
vicinity of stables, cucumber beds, &c, to. which, when
its numbers become annoying, attention should be
primarily directed, rather than having recourse to fly-
waters.
Another common insect (Bibio JiortulanuSj MEI-
GEN) lives in the larva state in cesspools, along with
rat-tailed larvae, &,c. The maggot of the bibio is very
peculiar in form. They are hatched from eggs with
shells as hard as Paris plaster, deposited on the adja-
cent walls, and frequently upon the pupa case which the
mother has previously quitted. Like the larva? of the
crane flies above described, this one moves itself chiefly
by means of its mandibles, and therefore it can make no
progress on a piece of smooth glass. Its skin, it may
be remarked, is so exceedingly hard and tough, that
it is no easy matter to kill it* We have introduced
this insect here, however, chiefly for the purpose of
refuting an erroneous popular accusation against
it, which is supported by the high authorities of
Ray and Reaumur. Our great English naturalist
calls it the deadliest enemy of the flowers in spring,
and accuses it of despoiling the gardens and fields of
* Swamrnerdain, x, 212.
BIBIO HORTULANUS.
267
every blossom.'* Reaumur is less decided in his opi-
nion; for though he perceived that, not being fur-
nished with mandibles, they could not, as is supposed,
gnaw the buds of fruit-trees ; yet, from their being
found crowded upon flowers and buds, he thinks they
may suck the juices of these, and thus cause them to
wither. | We are satisfied, by repeated observation,
that the fly only uses its sucker (haustellum) for sip-
ping the honey of flowers, or the gum with which
the opening bud is usually covered. The damage
of which it is accused is more probably done by cater-
pillars, snails, or other night-feeding insects, which,
not being seen by day, the fly is blamed for what it is
entirely innocent of.J
Transformations of Bibio hortulanus, Meigen. a, the egg
magnified ; 6, the same when hatched ; c, d, the maggot and
pupa magnified ; e, /, the same, natural size ; g-, the fly.
In the case of the blow-flies, LinnaBus tells us that
the larvae of three females of Musca vomitoria will
devour the carcase of a horse as quickly as would
a lion ; and we are not indisposed to take this
* Raii Hist. Insect. Pref. p. xi.
J. R.
t Reaumur, v. 56.
268 INSECT TRANSFORMATIONS.
literally, when we know that one mother of an allied
species (M. carnaria} produces about 20,000, and
that they have been proved by Redi to increase in
weight two-hundred-fold within twenty-four hours.
The most extraordinary fact, illustrative of the voracity
of these maggots which we have met with, is the
following, given by Kirby and Spence, from f Bell's
Weekly Messenger:'
' On Thursday, June 25th, died at Asbornby,
Lincolnshire, John Page, a pauper belonging to
Silk-Willoughby, under circumstances truly singular.
He being of a restless disposition, and not choosing
to stay in the \ arish work-house, was in the habit of
strolling about the neighbouring villages, subsisting on
the pittance obtained from door to door: the support
he usually received from the benevolent was bread and
meat; and after satisfying the cravings of nature, it
was his custom to deposit the surplus provision, par-
ticularly the meat, betwixt his shirt and skin. Hav-
irg a considerable portion of this provision in store,
so deposited, he was taken rather unwell, and laid
himself down in a field, in the parish of Scredington;
when, from the heat of the season at that time, the
meat speedily became putrid, and was of course
struck by the flies: these not only proceeded to
devour the inanimate pieces of flesh, but also literally
to prey upon the living substance; and when the
wretched man was accidentally found by some of the
inhabitants, he was so eaten by the maggots that his
death seemed inevitable. After clearing away, as
well as they were able, these shocking vermin, those
who found Page conveyed him to Asbornby, and a
surgeon was immediately procured, who declared that
his body was in such a state, that dressing it must be
little short of instantaneous death; and, in fact, the
man did survive the operation but a few hours.
When first found, and again when examined by the
UTILITY OF INSECTS. 269
surgeon, he presented a sight loathsome in the ex-
treme; white maggots of enormous size were crawl-
ing in and upon his body, which they had most
shockingly mangled, and the removing of the exter-
nal ones served only to render the sight more horrid.'
Kirby adds, c in passing through this parish last
spring, I inquired of the male-coachman whether he
had heard this story; and he said the fact was well
known. '* The year in which this remarkable cir-
cumstance occurred is not mentioned.
The importance of the insects just mentioned, in
removing with great rapidity what might otherwise
prove nuisances of considerable magnitude, naturally
leads us to notice another sort of larva, no less useful
in diminishing the numbers of the plant-lice (Jlphides)
which do so much damage to cultivated vegetables.
We do this also the more readily, that these very
insects, which are so beneficial to the husbandman
and the gardener, are often erroneously accused of
being themselves the cause of the mischief. A corre-
spondent of the Natural History Magazine, for exam-
ple, says, * the lady-bird is remarkably abundant this
season. The shrimp (larva) of this insect destroys
both turnips and peas in many parts of England, 'f
The truth is, however, that all the species of lady-
birds (Coccinellidce, LATH.), both in the larva and the
perfect state, feed exclusively on aphides, and never
touch vegetable substances. The eggs are usually
placed in a group of twenty or more upon a leaf,
where aphides abound; and when the young are
hatched they find themselves in the midst of their
prey. There are a considerable number of species of
this family (Mr Stephens enumerates fifty); but the
most common, perhaps, is the seven-spotted lady-
bird (Coccinella septempunctata) , whose larva is of
* Intr. i, 140, and note. t Mag. of Nat. Hist, i, 191.
rot, vi - 23*
270
INSECT TRANSFORMATIONS.
considerable size, and, of course, when abundant,
must destroy a vast number of aphides.
Transformations of the lady-bird (Coccindla 2-punctata, Linn.)
, the eggs. 6, the larva, c, the pupa, d, the beetle, e, th
same flying, y, Coccinella 20-punctata, Linn., flying.
The maggots of many species of a beautiful farm'lj
(Syrphidce, LEACH) of two- winged flies are also
voracious devourers of the aphides. These larvae are
of a tapering form, and they can contract or lengthen
their bodies to a considerable extent; while they have
a retractile instrument, armed with three prongs like
a trident, with which they transfix their helpless and
hapless victims. ' When disposed to feed,' says
Kirby, * he fixes himself by his tail, and being blind,
gropes about on every side, as the Cyclops did for
Ulysses and his companions, till he touches one,
which he immediately transfixes with his trident
VORACITY OF MAGGOTS.
271
elevates into the air, that he may not be disturbed with
its struggles, and soon devours. The havoc which
these grubs make amongst the aphides is astonishing.
It was but last week that I observed the top of every
young shoot of the currant-trees in my garden curled
up by myriads of these insects. ' On examining them
this day, not an individual remained; but beneath
each leaf are three or four full-fed larvae of aphidivor-
ous flies, surrounded with heaps of the skins of the
slain, the trophies of their successful warfare.'*
The larvae of the lace-winged flies (Hemerobidce,
LEACH) are even more destructive to the aphides than
either of the preceding; insomuch that Reaumur was
induced to call them the lions of the aphides. The
mandibles of the larva of Hemerobius are somewhat
crescent-shaped, and, like those of the ant-lion, are
hollow, by means of which they suck the juices of
their victims. These are rarely so numerous as the
two preceding families, but they make up for their
fewness in the voracity with which they devour the
little destroyers of our vegetables.
* Intr. i, 264.
a, Lace-winged fly ; 5, the grub of the same, magnified ; c,
syrphus ; rf, larva of the same devouring the aphides of the eld-
er ; , the head magnified, to show the mouth.
SECTION HI. PUPJE.
CHAPTER XI.
Mechanism of suspending Chrysalides.
A SAILOR would find it no easy process to cut for
himself a suit of clothes out of a set sail, holding, the
while, only by the portion that he was cutting
This is an operation which is performed every day by
the tent-making caterpillars.* Difficult, however,
as this may be considered to be, it appears as nothing
when compared with another problem performed by
'a different family of caterpillars. ' Country fellows,
for a prize,' says Kirby, 'sometimes amuse the
assembled inhabitants of a village by running races
in sacks : take one of the most active and adroit of
these, bind him hand and foot, suspend him by the
bottom of his sack, head downwards, to the branch
of a lofty tree; make an opening in one side of the
sack, and set him to extricate himself from it, to de-
tach it from its hold, and suspend himself by his feet
in its place. Though endowed with the suppleness
of an Indian juggler, and promised his sack full of
gold for a reward, you would set him an absolute
impossibility; yet this is what our caterpillars, in-
structed by a beneficent Creator, easily perform.'')"
The manner in which this is effected we shall now
describe.
A caterpillar, when about to change into a chry
* See Insect Architecture, p. 223. t Intr. iii, 209
SUSPENSION OF PUP^. 273
sails, usually steals away from the plant on which it
has been feeding, to find some secluded corner where
it may undergo its transformation unmolested; as if
it were previously aware that it would no longer be
able to escape from its enemies. Those which we
shall first notice climb up the highest objects near
them, such as walls, gates, palings, and trees, under
the projections of which they think they may begin
their operations in safety. Thus we once found a ca-
terpillar of the small tortoise-shell butterfly upon the
branch of a fir-tree, in Epping Forest, from ten to
twelve feet above its native patch of nettles below;
and we have seen the cabbage butterfly under the
lintel of a window on the third story. *
Having thus selected a safe spot, the caterpillar
begins, in order to attach itself securely, to weave a
mooring of silk, the structure of which is well worthy
of notice. The threads of which this is composed are
so fine, that they are not easily distinguished; and
we recollect being not a little astonished at seeing a
chrysalis of the admirable butterfly ( Vanessa JLia-
lanta) hanging within an inverted glass tumbler,
where we had confined it, the silk being transparent,
and all but invisible. It is necessary, therefore, in
order to see it distinctly, to confine the caterpillars
within a black box or other vessel. The silk threads
are not drawn tight along, so as to be parallel with
the surface, but are formed into a sort of projecting
button, the caterpillar, for this .purpose, alternately
raising and depressing its head over the spot so as to
draw out the threads, in the same way as a tambour-
ing needle is worked in making a dot upon muslin:
the base is accordingly made the broadest part, and
the centre the most projecting, for a reason which will
immediately appear.
When it has finished this little button of silk
* J. R.
274
INSECT TRANSFORMATIONS
n, Caterpillar of Fanessa Antiopa weaving its button of silk,
b, suspended by its hinder pro-legs from the silk button, c, bend-
ing in order to split the old skin.
which is thickly interlaced and strong, it turns round
to examine it with its hinder pair of pro-legs; and if
it judges it to be sufficiently firm, it thrusts these
among the meshes, taking secure hold with the nu-
merous hooks with which these are fringed,* and
swings itself fearlessly into the air, hanging with its
head downwards. All this seems easy enough of
performance, but it is only preliminary; for it has
still to throw off its skin, together with the hooks by
which it is suspended, and this without losing its
hold. The old skin is rent by the forcible bending
round of the upper part of the body, which pushes
through some of the angular projections of the chry-
salis a tedious and probably a painful operation, in
* See Insect Architecture, p. 307, right hand figure.
SUSPENSION OF PUP.E.
which it is often engaged the greater part of a day,
and sometimes two, according to its strength. When
the first rent is made, however, the included chrysalis
soon wedges itself through the breach, the lower por-
tion swelling out greatly more than the upper, so as
to form an inverted but somewhat irregular cone.
The included insect continuing its laborious exertions
by successively contracting and dilating the rings of its
body, pushes off the now rent skin by degrees from the
head towards the tail, as the sack-racers mentioned
by Kirby would disengage themselves from the sacks
in which they were inclosed, or as one would roll
down a stocking from the leg. There are two cir-
cumstances worthy of notice in this process: the
position of the insect in hanging with its head down-
wards, throws a greater portion of the fluids of the
body towards the head, by means of their weight,
which swell out the part that splits; and also pushes
back the old skin, while the sloughing skin is pre-
vented from resiliating by a series of pegs, which act
like the toothed rack of a sluice-gate. The old skin,
being by these means pushed towards the tail, is of
course compressed into several folds, which in some
degree prevent the extension of the rent, and serve
to keep the chrysalis from falling; for being now
detached from the skin, it has no hold upon the
meshes of the silk button, and is, in fact, at some
distance from it.
This, then, is the part of the process where the
"nicety of the mechanism is most worthy of admira-
tion; for the hooks by which the insect is in the first
instance suspended from the meshes of the silk are
sloughed off, together with the skin, the grasp of
whose folds becomes then the only support of the
chrysalis. But this chrysalis, now deprived of feet,
and some distance from the suspensory cordage of silk,
has still to reach this, fix itself there, and cast off the
276
INSECT TRANSFORMATIONS.
sloughed skin altogether. This operation causes, says
Bonnet, a spectator to tremble for the consequences,
for every movement seems to render its fall almost
certain. It is, however, provided with means which
answer the same purpose as hands, to enable it to
climb; it can elongate and contract at pleasure the
rings of its body. It accordingly, with two con-
tiguous rings, lays hold, as with a pair of pincers, of
the portion of the sloughed skin nearest the head; and
elongating the rings beyond this, seizes upon a more
distant portion, while it lets go the first. Repeating
this process several times, it at length arrives at the
silk button.
a, suspended caterpillar of Vanessa Antiopa splitting its skin
for the evolution of the chrysalis, fe, the head of the chrysalis
emerging, c, the same process farther advanced, d, the per-
fect pupa.
The tail of a chrysalis, to an ordinary observer,
would appear smooth, and quite unfitted for being
SUSPENSION OF PUP.E. 277
fixed to the silk in such a manner as to sustain its
weight ; but careful examination discovers that it has
been furnished with an efficient apparatus for this
purpose, in a number of very minute hooks, similar
to those of the pro-legs which have been sloughed off.
Feeling about then with its tail for the silk, it insinu-
ates these hooks among the meshes, and being no
longer in danger of falling, it can swing secure,
as it had previously done in the caterpillar state.
Reaumur has, however, seen some chrysalides
fall before they completed the process, in conse-
quence, as he thinks, of having spun too slight a
mesh- work of silk. In order to ascertain the cor-
rectness of this inference, we tried a series of experi-
ments upon a considerable number of a brood of the
peacock butterfly (Vanessa Jo), the same upon which
Reaumur made his observations. We allowed some
to spin only half the usual portion, and removed them
to another station. Here they eagerly recommenced
the task, and, if left unmolested, never fell from the
spot; but if previously removed a second time, they
seldom succeeded in completing the process in the
usual way. They did not, indeed, in such cases,
attempt spinning an imperfect silken suspensory ; but
abandoning in despair what they felt themselves in-
capable of performing, they crept down to the bottom
of the nurse box, and cast their skins without having
anything to which they could attach themselves.*
When the hooks of a chrysalis have been properly
fixed among the meshes, it remains suspended con-
tiguous to the skin which it has just cast ; but not
liking the neighbourhood of its now useless spoil, it
sets itself to get rid of it. For this purpose it con-
torts itself in various ways, sometimes assuming a
figure similar to an S, so that it may push against
* J. R.
VOL. vi. 24
273
INSECT TRANSFORMATIONS.
the spines of the old skin ; and then giving itself a
sudden jerk, it spins itself rapidly round a dozen or
twenty times. R aumur says that this gyration
usually throws off the slough, in consequence of its
being farther from the centre of motion, and there-
fore exposed to a greater centrifugal force ; but un-
luckily for this refined philosophy, it is not the silk
button, but the chrysalis which spins round, and con-
sequently the old skin does not twirl at all, and only
moves like a pendulum; the best method, evidently,
of disengaging the hooks it hangs by. Besides, the
threads of the silk are not broken by the gyration, as
Reaumur, followed by Kirby and Spence, asserts ;
otherwise the weight of the chrysalis would to a cer-
tainty break its threads, more easily than the sup-
posed centrifugal force would break those which
suspend the slough. Repeated observation has satis-
fied us, therefore, that the twirling of the chrysalis is
both for the purpose of disengaging the old skin arid
strengthening its own hold.* Bonnet may be right
or wrong in thinking the stimulus of the spines of the
old skin is the cause of the twirling : we have ob-
served that the insects which change into chrysalideSj
o, o, front and side view of chrysalides of fam-ssa vrti,
pended by their anal hooks. ,-, anal hooks magnified.
skin fallen off.
* J. K.
sus-
.% old
SUSPENSION OF PUP.&. 279
after being removed from their suspensories, also foil
about and manifest great uneasiness.*
But this is only one mode by which chrysalides
are suspended; for natuie, rich in variety, has taught
others to employ a different mechanism, and consid-
erably more complicated, not only fixing themselves
by the tail, but throwing around their body a girdle
of silk, which binds it firmly to the spot selected, and
frequently in a horizontal position. Amongst those,
the caterpillars of the pretty butterflies called by col-
lectors hairstreaks (Theclce, FABR.), are remarkable,
both for their resemblance in shape to the common
woodlouse (Oniscus), and for their singular proceed-
ings. In order to construct a silken cincture around the
middle of its body, after it has secured itself at the tail,
the Thecla draws back its head, and pushing out its
spinneret on one side, forms an arched thread by pass-
ing it over to the other side. It then insinuates its
head under this thread, and pressing the fore part of its
body down as closely as possible, it contrives to place
the girth over its middle. This circumstance is the more
remarkable when it is considered that the silk is so
fine as scarcely to be distinguishable to the eye, and
that the. back of the caterpillar over which it has to pass
is thickly bestudded with spines. The caterpillars, in-
deed, of- this whole family (Lyccenceidce, LEACH),
which includes our splendid blue and copper butter-
flies, seern to follow the same process, repeating it
from thirty to fifty times, in order to strengthen the
band. As the caterpillars of the family just men-
tioned are but seldom found, those who are desirous
of observing the formation of the cincture of a chry-
salis may readily gratify their curiosity by watching
a brood of any of the native white butterflies, as
those of the cabbage or of the hawthorn (Pieris
Cratcegi, STEPHENS). A caterpillar of this kind,
* Bonnet, OEuvres, vol. ii, p. 109,
280 INSECT TRANSFORMATIONS.
however, though it forms a silken suspensory girth
similar to the Lyccenceidce, constructs it in a different
manner. Instead of retracting its head, it takes
advantage of its great pliability, and bending itself
nearly double, fixes a thread, carrying it over to the
other side simply by turning its head. It repeats
this process a great number of times, till it has
formed a packet of threads sufficient for its cincture.
It then stretches its head out into a right line with
the body, and remains in this position till it casts its
skin. The usual position of the chrysalides belong-
ing to the family (Papilionidce, LEACH) in question,
is horizontal; but they frequently also hang vertically,
and at different angles. We possess one of the large
garden white butterfly (Pontia Brassicce), which
was bound horizontally on the upper surface of a
leaf of the abele tree (Populus alba), being laid, and
not hung, as is almost the invariable practice of the
species. The leaf, moreover, is drawn together in
cr, Caterpillar of the black-veined white butterfly spinning Its
suspensory band. 6, chrysalis horizontally bound to a branch. f
c, the butterfly (Pieria Cratcegi,) smaller than in nature. *
SUSPENSION OF PUP^E. 281
the manner of the leaf-rollers, another most unusual
and remarkable circumstance.^
Another caterpillar of the same family, that of
the swallow-tailed butterfly (Papilio Machaon,
LINN.), one of our finest but local native insects,
rhaving a body less pliable than the preceding, has
cecourse to a still different method of forming a
pincture. The proceedings of this beautiful cater-
tillar, distinguished by two retractile horns, like
hose of a snail, may be illustrated by the mode in
which a skein of silk is wound from the hand. The
insect first attaches the end of his thread to the spot
selected for hanging up the chrysalis, such as the
bend of a branch of fennel or wild carrot, on which he
has been feeding; and extends it outwards by the
hooks on his claws, by which means he keeps it
stretched till he fixes it on the other side, forming a
a, Caterpillar of the swallow-tailed butterfly, v. r eaving its sus-
pensory cincture. 6, the caterpillar suspended for its change,
c, the chrysalis suspended in a similar manner.
* J. R.
VOL. vi. 24*
282 INSECT TRANSFORMATIONS.
loop about twice the diameter of his body. He re-
peats this process successively till he has spun forty,
sixty, or as many threads as he deems strong enough
for his cincture; and then throwing it over his head
towards the middle of his body, he proceeds to dis-
encumber himself of his old skin.
As the numerous threads composing the cincture
are not glued together, but remain separate, it some-
time happens that they slip, in whole or in part, from
the claws of the caterpillar; and R< aumur had one
which was foiled in all its efforts to repair such an
accident. It did not, indeed; make any attempt to
spin a fresh cincture, probably from its materials
being exhausted or from want of strength; so that
when it could not recover the fallen and entangled
threads, it collected a few of them, suspended in
which it cast its skin, but they, being too weak to sus-
tain it, gave way, and it fell and perished.*
We will not revert in this place to the varied con-
trivances of those insects which construct coverings
either of silk or other materials for inclosing their
pupce, such as the silk-worm, the puss-moth cater-
pillar, the tent-makers, &c; but there is one family
whose proceedings are so singular that they well
merit investigation. We refer to the numerous spe-
cies of what are indefinitely termed common flies,
(Muscidce^, and some families allied to them. Un-
like most other larvae, these never cast their skins,
not even when they change into pupae. The mag-
got of the common blow-fly (Musca vomitoma), for
example, when about to undergo its transformation,
quits the carcase where it has been feeding, and bur-
rows for an inch or two into the first soft earth it can
meet with. Here it draws in its body into a shorter
compass, and the soft skin being thus condensed,
* Mem. sur les Insectes, vols. i, ix.
CONTRACTION OF PUPJ3. 283
it acquires in thickness what it loses in extension: its
moisture, also, disappearing by evaporation, or more
probably by internal absorption, it becomes hard and
tough, like thin parchment, and of a dull reddish-
brown colour. The form is now that of an oblong
ball; and it was from that circumstance termed an egg
by Redi and other early naturalists, a term at which
Svvammerdam takes great offence in this instance.
The various changes undergone by the included insect
were traced from hour to hour by Reaumur with his
usual patience and accuracy: but few of the minute
circumstances detailed by him would probably interest
our readers ; except that in casting its mandibles,
which are henceforth useless, they are not thrown off
on the outside of the case, but remain on the inside.
Were such an extraordinary transformation as this
to happen to one of the larger animals, it would be
held forth as altogether miraculous. Were a lion or
an elephant, for example, to coil itself up into a ball,
compressing its skin into twice the thickness and half
the extent, while it remained uniform in shape and
without joinings or openings; and, at the same time,
were it entirely to separate its whole body from this
skin, and lie within it, as a kernel does in a nut, or a
chick in an egg, throwing off its now useless tusks
into a corner, and then, after a space, should it
acquire wings, break through the envelope, and take
its flight through the air, there would be no bounds
to our admiration. Yet the very same circumstances
in miniature take place every day during summer,
almost under the eye of every individual, in the case
of the blow fly, without attracting the attention of one
person in a million.
The maggots of the genus of two-winged flies
(Syrphidce) mentioned above as feeding voraciously
on aphides, do not, like those of the blow-fly, burrow
in the earth, but attach themselves to a leaf or a
284
INSECT TRANSFORMATIONS.
branch. Being furnished with a species of adhesive
gluten, a maggot of this sort applies a portion of this
with its mouth to the spot which it has selected for
its transformation, and, pressing its body upon it,
becomes immoveably glued down there. When thus
securely fixed, it contracts and shortens its body
similarly to the maggpt of the blow-fly; but, instead of
becoming like that, uniformly oblong, the head swells
out and the tail becomes slender, {ill it terminates in
a point, just reversing the previousjbrm of the mag-
got, which is rounded at the tail and pointed at the
head. When the change is completed, indeed, it
is a good deal in the form of one of Prince Rupert's
glass drops. When we first met with these pupae, in-
deed, we concluded they were galls, arid were not a
little surprised to see large wasp-looking fiies issue
fromtfiem; but as they may be found in considerable
abundance, it becomes easy to gratify curiosity and
to confirm the facts just stated. It may not be out of
place to remark, that several species of ichneumon
o, Pupa of blow fly. 6, the s:>.me magnified, r, head of pupa-
rium opened 10 show the cast mandibles, d, pupa of
PUP^E OF LADY-BIRD. 285
flies make reprisals upon them for their destruction of
the helpless aphides. Swarnmerdam observed eight
of these parasites issue from one pupa of a Syrphus.*
The lady-birds (CoccindlidcR) glue their pupae to
leaves in much the same manner with the flies just
mentioned: but their skin, instead of becoming smooth,
wrinkles up by the shortening of the body of the
grub; because it is not so soft and pliable, and
cannot, therefore, be compressed. The interior, how-
ever, is smooth. ^
Those insects which live during their first stages
in the water, exhibit a very different economy when
they change from larvae into nymphs, as may be
exemplified in the May-flies (Ephemeridce) and the
dragon- flies (Libellulina). But as these will require
to be described in a future page, we shall content our-
selves at present with an account of an interesting
but minute species of tipulidan gnat ( Corethra plu-
micorwis, MEIGEN), of a straw colour, whose history
was first given by Reaumur and De Geer. The
latter was induced, from the beautiful transparency
of the larva, to name it Tipula cristallina, a qua-
lity which renders it, its size being also very minute,
rather difficult to discover: it is however, a good
subject for microscopical observations. Taking ad-
vantage of the recent improvements in microscopes,
Dr Goring has accordingly given coloured figures
both of the larva and pupa, as observed by him, in
which he has added a few minute detailsj that are
not in the otherwise very accurate figures of R/au-
mur.
The larva is rather less than a quarter of an inch
long, and somewhat resembles in form those of the
same family, particularly in the parts about the head,
* Part ii, p. 99. t J. R.
$ Goring and Prilchard's Nat. Hist., No. 1; and Reaumur,
vol. v., mera 1.
286 INSECT TRANSFORMATIONS.
the mandibles being horny, jointed, and capable of
uniting into one pointed borer. The tail is furnished
with plumed bristles, wuich appear to serve the pur-
pose of fins. The nearer this crystaline larva is to
its transformation, the more distinctly may be seen
four kidney-shaped transparent bodies, of a brown
colour, a pair on the fourth ring from the tail, and
another pair at the shoulders. The former, perhaps,
serve to inclose the tail fins of the pupa; the latter
the horns of the pupa, which again encase the an-
tennas of the gnat; but in another species (Corethra
culiciformis) _De Geer supposed these to be respi-
ratory organs. We are not aware that this larva has
been actually seen to cast its skin, but there can be
no doubt of the fact, for Reaumur found exuviae at
the bottom of the glasses where he kept them;* and
we are not, consequently, authorized to assert that its
transformation is 4 not effected, as in other insects,
by casting the outer skin, but by an actual conver-
sion of one form of matter into another. '| We
watched above a hundred of them without being so
fortunate as to see their transformation into pupae,
though we more than once observed the emergence
of the fly.
Our chief reason, however, for introducing it here,
is to show the mode in which the pupa is suspended,
or rather buoyed up, in the water, by means of its
foliated tail and the shape of its body, which is
bulged out above, and narrowed as it approaches the
lower extremity. It is, besides, very lively in the
pupa state, and jerks about with great .agility, but
usually keeps close to the surface of the water, so as
to project its horns or antennae cases above it. In,
the figures we have endeavoured to combine the
details of Reaumur and Dr Goring.
* Reaumur, vol. v., p. 41-2.
f Goring and Pritchard, Nat, Hist., No. 1, p. 23,
PUP.E OF GNATS.
287
#, a larva of Ccrcihra plumicornis magnified. 6, the man-
dibles and palpi, c, the respiratory fins. , the pupa magnified,
e, pupa, natural size. /, larva, natural size, t, the female fly.
h, the male fly .
We possess a small aquatic pupa which is furnished
at the tail with four horny hooks resembling the
prickles on the stem of a rose-tree, and evidently
intended as suspensory appendages. It was found
hanging to a deal board, which had been immersed
in running water, and seems from its form to be the
pupa of a moth (Hydrocampa?)*
* J. R.
CHAPTER XII.
Form and Structure of Pupae.
THE figures delineated in the preceding chapter
show how different in form many pupae are, both from
their larvae and from the insects to be afterwards
evolved from them, as different, indeed, as the form
of a bud from the seedling tree, or from the leaf,
branch, or blossom, which is destined to shoot from it.
Pupae, as we formerly remarked, have as striking an
analogy to the buds of plants, as eggs have to seeds;
and this is the more necessary to be insisted on,
that their nature has been grossly misrepresented
even by authors of eminence, and, in other matters, of
unquestionable accuracy. The term Metamorphosis,
so long applied to the various stages of insect life,
has been one of the chief means of propagating the
erroneous views in question, inasmuch as it implies
a supernatural change like those described in the
poetical fables of Ovid. The term Transformation,
though not perhaps free from a similar implication,
is much less strong and less likely to mislead.
That our objection does not originate in hypercri-
tical nicety, but is of no little importance with regard
to the accurate knowledge of the history of insects,
could be proved by reference to many well-known
works of natural history; but we shall limit our
illustrations to one or two of those strange fancies
which have obscured and perplexed this branch of
our subject.
We shall begin with the illustrious Harvey, the
discoverer of the circulation of the blood, who, in
OPINIONS RESPECTING INSECTS, C 289
his exercitations on the generation of animals, says
* There are two ways in which we observe one thing
to be made out of another (as out of matter), both
in art and nature, especially in the generation of
animals: one is, when a thing is made out of ano-
ther already in being, as a bed out of wood, and
a statue out of a stone; when, for example, all
the materials of the workmanship exist before the
workman begins the work or attempts to give it any
form. The other way is, when the stuff receives both
being and form at the same time. As, therefore, the
works of art are performed two ways ; the one by the
workman's dividing, cutting, and paring away the
matter prepared for those operations, so as to leave
behind, like a statuary, the figure of the thing he
intends to make: the other, by the workman's adding
and moulding, as well as paring away, the materials,
and at the same time tempering the matter itself, so
as to produce, like a potter, the figure; which, for
this reason, may be said to be made, rather than
formed; in the same manner it happens in the
generation of animals ; some of which are formed and
transfigured out of matter already digested and in-
creased for this purpose, all the parts springing out
together distinctly by a kind of metamorphosis, and
thus forming a perfect animal, while other animals are
made piece by piece.'
He proceeds to tell us, that the generation of insects
is performed after the first manner; the egg, by
metamorphosis, producing the worm; or matter in a
state of putrefaction, when it becomes too dry or too
moist, producing the primary rudiments; and these
again, by metamorphosis, a caterpillar, which, when
grown to its full size, is metamorphosed into an aurelia
(pupa), a butterfly, or a common fly. ' Bees,' he
subjoins, c wasps, hornets, or butterflies, and whatever
VOL. vi. 25
'290 INSECT TRANSFORMATIONS,
other animals are generated by metamorphosis from a
creeping insect, are said to be the offspring of chance,
and therefore never to keep up their species. But
the lion or cock are never produced spontaneously or
by chance. In the generation by metamorphosis,
animals are fashioned as it were by the impression of
a seal, or framed in a curious mould, all the matter of
which they consist being transformed.'*
Goedart, a later naturalist of eminence, both falls
into the foolish fancy of supposing that the form of
the human face can be traced in the chrysalis, of
which he has actually given a figure in his plates,
as Reaumur has done after him; and also tells us,
c that wherever the legs are situated in the cater-
pillar, there is placed the back of the insect which is
to arise by transmutation; and, on the contrary,
where the back of the caterpillar was, there are the
legs in the insect to be produced from it. This
metamorphosis,' he adds, ' is performed in a short
space of time, so that it may be distinctly seen; be-
cause, immediately after shedding its skin, this change
appears to the eye.'t
Had this most absurd and untrue doctrine passed
into oblivion, or become obsolete, we should have
passed it by in silence; but as, like many of the
theories of former ages, it often meets us even in*
modern books,J where we might least expect to find
it, we deemed it proper to give it in the language of
two of its most eminent advocates, which Swammer-
dam justly says contains almost as many errors as
words. The best method of opposing and over-
turning error being the simple explanation of the
truth, we shall proceed to describe the form and
Harvey, de General. Anim., Esercit. xlv.
t De tnsectis, Exp. 77.
+ See our quotation from Goring and Pritchard, p. 286
STRUCTURE OF PUP^. 291
structure of pupae, rather than stop to refute cir-
cumstantially the preceding theory of Harvey and
Goedart.
In the pupa state, then, we may remark, that the
legs, wings, and other external appendages of the
insect, are, in the greater number of instances, closely
folded up and enveloped by an external covering,
usually of a membranous structure, and differing
considerably both from the skin of the larva and from
that of the perfect insect. It is as different, indeed,
as the winter envelope of the bud of a tree is from
the bark or from the cuticle of a leaf. The angular
forms exhibited in some chrysalides, are for the pur-
pose of encasing particular limbs, &,c, of the insect
which Providence has not seen meet to fold down
smoothly to the body. The spines, hooks, and hairs,
again, which are also of occasional occurrence, and
which Goedart strangely enough mistook for feet,*
are manifestly for aiding the animal in casting its old
skin, as has been explained in a preceding page;
while the grooves, ridges, and other markings, are
the indications of the various members of the insects
folded up, or otherwise disposed under them.
As we have shown all the parts of the perfect insect
contained in the caterpillar, so these can be much
more easily exhibited in the pupa, particularly when
near its final change; for in more early periods the
substance is so soft and pulpy almost fluid indeed
that it would be next to impossible to develop
them artificially. In some pupa3 the parts can even
be seen through the membranous envelope, which in
other cases requires, for this purpose, to be removed.
In order to exhibit this, we shall select a few instances
in which the facts may be readily verified, by those
who will take the trouble of breeding the insects.
The first we shall advert to is that of the chame-
* Goedart, de Inscctis, 77,
292
INSECT TRANSFORMATIONS.
leon fly (Stratiomys chameleon), whose singular
larva we formerly described.* When this draws near
the period of its transformation, it leaves the water,
betaking itself to the adjacent bank, or to the plants
which float on the water, creeping up so as to leave
only a part of its tail submersed. In this position
it. remains, contracting itself by degrees in a manner
scarcely perceivable, and losing all power of loco-
motion. The internal portion of the tail at the same
time separates gradually and insensibly from the
exterior skin, becoming greatly contracted; and, ga-
thering into three or four curvatures, the extremity is
thereby left empty. Into this space the air penetrates
and soon fills the place previously occupied by the
body, which is now contracted to one-third of its
former size. When the air is prevented by too much
A, Pupa of chameleon fly, with the lid of the puparium raised.
B, the same magnified, and the puparium laid open to show the
embryo fly. C, the embryo fly magnified : a a, antennae ; b 5,
the eyes; r, sucker; d rf, first pair of legs: e e, second pair ;
//, the wings folded up ; g- h j, rings of the body ; k k, breath-
ing-tubes.
* Page 156, 7.
FORM OF PUP^E. 293
moisture from entering and distending the skin, it
shrivels up; but this occurs seldom. If the old skin,
now become detached and forming a tubular enve-
lope, be cut open, the pupa will be brought into view,
exhibiting the parts of the future fly neatly folded
down upon the body, as may be seen in the figure.
This is one of the larvae which Swammerdam ob-
served to cast, along with its external skin, the lining
of the intestines, and breathing-tubes likewise, which,
he remarks, * is very singular, and amazingly shows
the miracles of God, teaching at the same time how
the former body is entirely cast off and renewed .'*
The pupa, when exposed in the preceding manner, is
of a bright green colour, interspersed with white
transparent particles, and the spiracles of the wind-
pipe glittering like pearls.
When the pupa of the lappit moth (Gastropacha
quercifolia) is disengaged from the cocoon, it has
much the appearance of an Egyptian mummy, or an
infant in the old-fashioned swaddling bands. The
feet are crossed over the breast, and folded closely
down nearly in the same manner as in the instance
of the chameleon fly just mentioned; but the wings
are compressed into a very small compass. This
appears the more remarkable as the wings of the
moth are large and conspicuous, and so like the
withered leaf of an oak, both in form and colour, that
the insect would readily impose upon a careless
observer. It is, we believe, the only British example
of what have been popularly termed leaf insects,
which have given origin to the fanciful and untenable
theory of intentional deception oh the part of Provi-
dence. It was by opening one of these pupso that
Heaumur first discovered the various sheaths appro-
priated to the feet, the antennae, and the wings; the
sheath of the sucker (haustellum) being wanting, as it
* Bibl. Nat. vol. ii, p. 5-1
VOL, vi. 25*
294
INSECT TRANSFORMATIONS.
is obsolescent in the moth. It is furnished, however,
with a peculiar horn or projection on the forehead,
the palpi which the theorists to whom we have
alluded might term its leafstalk.
a, Pupa of lappit moth. 6, under side of the moth, with its
feet folded up. c, side view of the same.
We can demonstrate the same position still more
obviously in the chrysalis of a butterfly, for ex-
ample, in that of the peacock ( Vanessa 70), whose ca-
terpillars feed on the nettle. This chrysalis is an-
gular like the others of the genus, the two termi-
nating angles encasing the eyes, and the four lateral
ones the marginal folds of the wings, the contour of
which is disposed on what may be called the shoulder
of the chrysalis (Ptero-theca, KIRBY). The legs, an-
tennae, arid sucker, are folded down longitudinally
upon the breast, very similarly to what occurs in the
moth just described. When the membranous cover-
ing, which is thinner but more firm and elastic than
Indian paper, has been carefully removed, selecting
for this operation an advanced period of the chrysalis,
the several members of the butterfly may be seen
STRUCTURE OF PUPJE.
295
folded up in the manner we have here indicated.
The wings are still covered with moisture, so that the
powdery down which clothes them is scarcely visible,
and they have not yet assumed their beautiful colours
and elegant markings, but are of a dusky ash-gray.
The legs, however, are already so firm that the insect
moves them about, and also coils up its sucker, and
plays its antennae. It is worthy of remark, that the
a, under side of the chrysalis of the peacock butterfly. &, the
winjjs and antennae triced out from the same, r, the perfect in-
scvt (Faneata lo) fully developed.
296 INSECT TRANSFORMATIONS.
membrane which covers the more prominently exposed
parts, such as the legs, is considerably thicker than the
other portions.* Our description will be rendered
more intelligible by the preceding figures.
It will obviously appear from these details, in what
manner superficial observations led to the fancy of
one insect being on a sudden miraculously metamor-
phosed -or transmuted into another. Those, indeed,
who persuaded themselves that a morsel of tainted
beef, or a bit of rotten wood, could, by some inexpli-
cable chemistry, grow into limbs, wings, eyes, and all
the other parts of an insect, with its admirable orga-
nization of muscles, nerves, and digestive apparatus,
had no difficulty to overcome in believing that the
green pulpy mass of a chrysalis could be transmuted
into the light airy wings of a butterfly : nay, they con-
sidered the matter as proved, and admired the sup-
posed metamorphosis, without giving themselves the
trouble of investigating whether it was real or possi-
ble. *(* Accurate observation, founded on the princi-
ples of the Baconian philosophy, gradually put to
flight the reveries of those who (to use the words of
Harvey) ' philosophize by traduction, who are not a
whit wiser than the inanimate books through which
they come at their ill-digested notions. 'J Yet this
distinguished physiologist, though he could so express
himself, occasionally struck upon the very sand-bank
of which he here warns us to take care; perhaps in
consequence of a cause shrewdly and profoundly
assigned for philosophical errors by Des Cartes, in
his Essay on Method, who says, ( I was always of
opinion, that more truth is to be found in those
reasonings which men make use of in the common
affairs of life, whose bad success may prove a kind of
punishment for their reasoning ill, than those which
* Swamraerdam, vol. ii, p. 17.
t Reaumur, vol. i, p. 350. t Harvey, De Gen. An., Exer- 44.
STRUCTURE OF PUP.K. 297
some idle doctor, cooped up in his study, has in-
vented, that conduce nothing to the ease and happi-
ness of life, and from which he expects no other ad-
vantage unless that of reaping so much the greater
harvest of empty glory from his arguments; as they
contain less of truth and common sense, on account
of the extraordinary strength of genius and applica-
tion requisite to give an imposing air to such ab-
surdities. 7
It was the decided opinion of Swammerdam that
the several transformations of insects, particularly the
change from the egg to the caterpillar, and from the
pupa to the perfect insect, are chiefly effected by the
evaporation of the superabundant fluids. Thus he
tells us that the nit, or egg of the louse (Pediculus
humanus), is nothing mare than the insect itself,
which only requires the evaporation of the surround-
ing moisture and the casting of the old skin, to bring
it to its perfect form.* It is not a little surprising
that so very accurate a naturalist should never have
thought of investigating the truth of such an opinion
by experiment. That he neglected this precaution, is
an instance, among thousands more, of the imperfec-
tion of human studies; for his very first trial would
have demonstrated the error, which pervades every
page of his great work. He was evidently misled
into the opinion by perceiving how fluid the contents
of an egg or of a pupa are when opened previous to
their change, and how dry the insect is upon its
evolution.
It is much more surprising to find Kirby and
Spence repeating the same, or nearly the same opi-
nion, at the very time, too, when they are in the act
of quoting the experiments of Reaumur, by which it
is refuted, though the great experimenter himself mis-
interpreted them. ( If you open a pupa,' say they,
* Swammerdam, passim.
298 INSECT TRANSFORMATIONS.
c soon after its assumption of that state, you will find
its interior filled with a milky fluid, in the midst of
which the rudiments of its future limbs and organs,
themselves almost as fluid, swim. Now the end to
be accomplished during the pupa's existence is, the
gradual evaporation of the watery parts of this fluid,
and the development of the organs of the enclosed
animal by the absorption and assimilation of the resi-
duum.'* The evaporation, however, is so very
inconsiderable, that it is evidently only of secondary
consequence.
When the great quantity of fluid in the body of the
chrysalis is taken into consideration, we must infer
that if it were evaporated to any extent, the insect
would be reduced to a mere shadow. We are dis-
posed, therefore, to agree with Reaumur in thinking
it more probable that the fluids of pupae become
united to the more solid parts, in the same way
as the blood and lymph in our own bodies go
to the extension or to the repair of our bones and
muscles. To put this to the test of experiment,
Reaumur, in the month of July, accurately weighed
two chrysalides the instant they were disencumbered
of the sloughs of the larvae. The lightest weighed a
trifle less than 18, and the heavier a trifle less than
19 grains. Putting them aside separately, with a
note of their respective weights, he re-weighed them
every two or three days for sixteen days successively,
that is, till they were transformed into perfect insects.
On the last day, the lighter weighed more than 17,
and the heavier more than 18 grains; consequently
the fluid evaporated during this period did not amount
to a grain, perhaps not to more than i of a grain. On
weighing the insects themselves which issued from
these pupa, together with the cast slough, the weight
was not sensibly different. The fluid, therefore,
* Introd. iii, 262.
STRUCTURE OF PUP.E. 299
which escapes by what is termed insensible perspi-
ration, is not so great as might have been supposed.
To ascertain what it was, Reaumur enclosed several
chrysalides, whose envelope seemed very dry, in se-
parate glass tubes, terminating at one end in a bulb,
and at the other hermetically sealed. He kept these
in a temperature of from 14 to 15 of his own
thermometer, corresponding to 63 65 Fahr. ; and
in a few days minute drops of water appeared on the
sides of the tube, which rolled down into the bulb
in form of a large drop not * eight or ten large
drops,' as Kirby and Spence, by some oversight,
have stated.*
It would certainly be considered a strange and
untenable doctrine to maintain that it is the evapo-
ration produced from the egg by the heat of the in-
cubating mother, which causes the development of
the chick in the egg ; yet this is precisely similar to
what is maintained by Swammerdam, Kirby, and
Spence, the chief difference being, as Reaumur ob-
seves, that the chick has obvious organs for appro-
priating the nutriment contained in the egg, while the
insect in the pupa is surrounded, and, as it were,
bathed by the fluid, whose passage into the interior
vessels we cannot trace by the eye.j" That they do
find their way thither, the experiments above recorded
unanswerably demonstrate.
The pupaB of insects, though they, in most in-
stances, cease from locomotion, and appear torpid,
are by no means really so; for it would be no less
incorrect to look upon them in such a light, than to
consider an ox torpid when reclining in a meadow to
ruminate and digest the grass he had just been de-
* R/aumur, vol. i, p. 373, * Unegouttc beaucoup plus gros-
se ;' and Kirby and Spence, Intro, lii, 262.
f Mem. vol. i, p. 362, &c.
300
INSECT TRANSFORMATIONS.
vouring. This is, in fact, the nearest analogy which
occurs to us among the other classes of animals;
for the pupa, though it does not chew the cud like
the ox, assuredly rests for the purpose of digesting or
(if the term be preferred) of assimilating the cruder
fluids stored up by the caterpillar, and forming or
perfecting therefrom the organs and members of the
mature insect.*
Some pupae have a slight motion, particularly of
the lower parts of the body, and a few others differ
little from the perfect insect, continuing to move and
feed ; but the greater number remain apparently mo-
tionless. That they have internal though impercep-
tible motions, however, is proved by their possessing
similar organs of respiration with caterpillars and
pefect insects. We have adverted, in a former page,
to the eighteen spiracles which communicate with
the double windpipe of caterpillars, and the same ap-
paratus is always found in chrysalides, situated on
the sides of the abdominal rings. This we think
might have convinced such distinguished observers
as Lyonnet andMuschenbrok, that the most quiescent
pupae could not exist without breathing.
r, Chrysalis of Gonepteryx Rhamni. 6, pupa of Laria feucelina.
c } pupa of Sphinx Ligustri.
* J. R.
STRUCTURE OF PUP^. 301
Reaumur and De Geer proved this position by
numerous experiments. When a chrysalis, for in-
stance, is suspended by a thread and immersed in oil
up to the tip of the wing-cases, it does not seem to
be much injured, and the perfect insect is disclosed
in due time. If respiration, therefore, be essential to
the life of the chrysalis, it appears as if it could exist
with at least the greater number of its spiracles ob-
structed ; but this does not happen with a chrysalis
just formed, which always dies. JBy immersing the
whole chrysalis in oil, it is certainly killed; and even
by immersing its head downwards as far as the first
pair of spiracles situated near the head. This seems
to indicate accordingly that this first pair is more es-
sential to the insect than all the rest; and in other ex-
periments it is also found to emit a much greater
quantity of air by this first pair. It seems of much
importance in such experiments to attend to the age
of the pupa; for when near the change the function
of respiration is carried on more feebly, and at length
nearly ceases.
Besides the decisive experiments of immersion in
oil, Reaumur placed pupa3 of various species in the
exhausted receiver of an air-pump, and at every
fresh stroke of the piston their bodies both bulged
out and became elongated : because, as he inferred,
the envelope is not pervious to the air contained in
the body, and the spiracles do not allow of its escape
with sufficient rapidity to keep pace with the ex-
haustion of the receiver; contrary to what happens
when caterpillars are subjected to the same circum-
stances. Varying his experiments, he placed in the
exhausted receiver a vessel containing water deprived
of its air, and in this plunged a chrysalis, keeping
it immersed by means of a weight attached by a
thread. At the two or three first strokes of the pis-
ton, bubbles of air appeared at each of the spiracles.,
VOL. vi. 26
302 INSECT TRANSFORMATIONS.
issuing by jets, and a few smaller bubbles over the
body of the chrysalis, probably from not taking the
precaution afterwards suggested by Bonnet, of
moistening it before immersion.*
Upon examining the structure of the spiracles,
M. Reaumur farther discovered that their mouths are
furnished with ciliary valves, which are shut when
the pupa is plunged into water, but opened again
when it is taken out. This circumstance accounts
for the swelling of the body under the exhausted
receiver of the air-pump, for it may be supposed the
animal would closely shut the valves when it felt the
air forcibly extracted from its body. It is remarkable,
however, that though the shutting of the valves pre-
vents the entrance of water, it has not the power of
excluding oil ; because, as Reaumur conjectures,
it is not in the ordinary course of its nature exposed
to such an accident, and therefore Providence made
no provision for it.t It may be recollected that the
larvas of the cheese-fly and of blow-flies are provided
with a sort of valve with which they can cover such
of their spiracles as become immersed in any greasy
matter. J
a b
Spiracles of pupae, a, the valve open ; 6, the same shut.
In the aquatic pupa of the ringed China-mark-
moth (Hydrocampa stratiotata, STEPHENS) De Geer
* Bonnet, GEuvres, vol. iii, p. 39, &c. t Mern. i, 407, <Src.
t See page 265.
STRUCTURE OF PUPJE. 303
found three pairs of conspicuous spiracles, occupying
the second, third, and fourth rings, and placed on
cylindrical tubes. It is worthy of remark, that the
caterpillar spins a double cocoon, the outer of a thin,
and the inner of a close texture; and when the respi-
ratory gills of the larva are cast off with the old
skin, the insect knows how to surround itself with an
atmosphere of air in the midst of the water where it
resides, the inner cocoon being impervious to moisture.
How it contrives to renew this air when vitiated is
not yet known, but that it derives it from the water
is proved by its always dying if removed into the
air.*
We have formerly described .the beautiful appara-
tus for respiration in the Iarva3 of the gnat family
Culicidce, LATR.);| but this is rivalled by the organs
destined for the same purpose in their pupae, which
organs are situated in the head instead of the tail.
The pupa, in the same way, changes its position in the
water, swimming with its head upwards instead of
downwards as before. To enable it to maintain this
position, the pupa is farther provided with a fin-tail, like
a fish, by which it can move itself at pleasure in the
water. It no longer, indeed, requires to take food, but
air is indispensable to it;, and water being so unstable,
were the pupa incapable of swimming, it would seldom
escape being drowned. Its respiratory apparatus
consists of two tubes, situated behind the head, on
what may be called the shoulders. They are of a
funnel shape, and project very sensibly, though we
should not be disposed to compare them, as Reaumur
does, to asses' ears. The transparency of this pupa
renders it easy to see in it the parts of the gnat.
An apparently more simple, though no less remark-
able, apparatus for respiration, was observed by
Reaumur in the pupa of a small crane fly (Tipula,
* De Geer, Mem, i, 531. t See page 156..
304
INSECT TRANSFORMATIONS.
). This consisted in a single tube, two or
three times longer than the body of the pupa, and as
fine as a hair. The point of this hair always remains
above or at the surface of the water, for the purpose
of carrying on respiration, till the perfect fly is ready
to emerge from the water.
6, telescopic-tailed pupa of the same.
c, front view of the pupa of the common gnat (Culex pipiens.)
d, side view of the same.
v In another genus of this family the external organs
of respiration are very elegant in form, resembling
more the fibrillae of minute aquatic mosses (Con-
fervoidece} than the appendages of an animal. The
larva of this insect is well known to anglers, under
the name of the bloodworm; though we do not find
it mentioned by Walton, Brookes, Best, Sir H. Davy,
or any of the other writers upon angling. It is
usually less than half an inch long, flat, and jointed
like the wire worm, with several small appendages at
the tail, which appear to be breathing-tubes, of the
STRUCTURE OF
305
nature of gills; for the larva lives under water in streams
and ditches, enclosed for the most part in a tube of earth.
It is of a fine crimson colour, the origin of its popular
name; but it becomes more dark and opaquein the pupa
state.
The appendages which are thrown off by the larva
a, Chironomus ptuvwsus. 5, larva of the same, called the Blood worm,
d, pupae of ihe same, magnified to show their plumed spiracles.
VOL. vi. 26*
306 INSECT TRANSFORMATIONS.
are replaced by a brush-like bunch of bristles, the
points of which, it is probable, have the power of
extracting air from the water; and a similar coronet is
produced on each side of the head, disposed in a five-
rayed star of plumes. It is not a little remarkable,
that a double envelope for the feet projects from each
side of the breast, a circumstance which seems pecu-
liar to this insect. In a few days it is transformed into
a pretty gnat, with feathered antennaB (Chironomus
plumosus, MEIGEN).
Such are a few examples of the beautiful contriv-
ances for carrying on the important process of respira-
tion in that stage of life during which few insects take
any food. Considering the great difficulties presented
to us in the investigation of this subject, we may well
wonder that experiments have elucidated and proved
so many facts. We are still ignorant, however, of the
nature of the effects produced by respiration on the
fluids of pupae.
CHAPTER XIII.
Transformation of Pup into perfect insects.
THE period which pupae require to come to matur-
ity seems to depend mainly on temperature and size,
though there are several other causes at work appa-
rently inscrutable to human research. Those who
adopt, after Swammerdam, the untenable theory of
evaporation being all that is requisite to bring an insect
to maturity, tell us that these two circumstances will
account for all the phenomena; but we shall immedi-
ately have to record several curious facts quite at vari-
ance with such a conclusion. c It is plain,' say Kirby
and Sperice, * that this necessary transpiration, other
circumstances being alike, must take place sooner in
a small than in a large pupa. Since the more speedy
or more tardy evaporation of fluids depends upon their
exposure to a greater or less degree of heat, we might,
a priori, conclude that pupae exposed to a high tem-
perature would sooner attain maturity, even though
larger in bulk, than others exposed to a low one: and
this is the fact. The pupa of a large moth, which has
assumed that state in th early part of summer, will
often disclose the perfect insect in twelve or fourteen
days; while that of an ichneumon, not one-hundredth
part of its size, that did not enter this state till late in
autumn, will not appear as a fly for seven or eight
months. But this is not the whole. The very same
insect, according as it has become a pupa at an earlier
or a later period of the year, will at one time live but
308 INSECT TRANSFORMATIONS.
a few weeks, at another several months in that
state.'*
But though we admit all these facts, which are
known to every naturalist, and too well ascertained to
be denied, we submit that the inference of evaporation
being the exclusive effect, is, upon the whole, inad-
missible. Reaumur, though he does not absolutely
state his belief in such an inference, shows by his rea-
soning that he was strongly disposed to adopt notions
closely bordering upon it. The theoretical doctrine,
it may be perceived, takes for granted that evapora-
tion is the only result of heat ; overlooking the no less
obvious effect of expansion, besides the disposition it
produces in chemical principles to combine or be de-
composed. But these are only some of its inanimate
results, which would occur upon material objects inde-
pendently of life; whereas in living bodies, what may
be called chemical changes are frequently very differ-
ent from what can be effected out of the living body,
and consequently we cannot trace all the effects pro-
duced by heat in the two great internal processes of
secretion and consolidation. In detailing, therefore,
the interesting experiments of Reaumur on pupa?, which
he subjected to different degrees of heat and cold, we
shall not adopt his inferences respecting evaporation
The accuracy of the experiments themselves is un
questionable.
Reasoning from some of the facts above stated,
Rfaumur thought it might be possible to hasten or
retard the exclusion of insects from their pupa?, in
the same way as some flowers are forced to blow
early, and others kept back Trom blowing at their due
season; and he commenced a series of experiments to
ascertain the facts. In January 1734, he accordingly
placed a great number of the chrysalides of moths
and butterflies of various species in one of the royal
* Intr. iii, 263.
EXPERIMENTS ON INSECTS. 309
hot-houses at Paris. His success was equal to his
expectations, for the insects appeared in the middle
of winter, some in ten or twelve days, and others in
from three to six weeks from the time of their removal
into a warmer atmosphere. Five or six days, indeed,
seemed to be equal to a month of natural temperature.
A week was even equal to a month for the chrysalides
which naturally required the temperature of mid-
summer to bring them to maturity ; because the arti-
ficial temperature was both high and more uniform,
particularly during the night. The butterflies and
moths thus forced into premature appearance, were
equally full grown, healthy and lively, with those
produced in the usual way ; and the females deposited
their eggs and soon afterwards died, as they always
do in summer in the open fields. The life of these
insects was, therefore, shortened by some months.
The following November, Reaumur tried a similar
experiment, which was consequently begun two
months earlier than the former ; and the insects were
also evolved proportionally sooner. Those, for ex-
ample, which ought naturally to have appeared in
May, he obtained in December. In butterflies which
have a double brood, such experiments become still
more interesting to the physiologist. The beautiful
swallow-tailed butterfly (Papilio Machaon) is one of
those which are double brooded, the first going into
chrysalis in July, and the butterfly appearing in
thirteen days ; the second, in the autumn, and the
butterfly not appearing till the succeeding June. But
if placed in an artificial temperature of due warmth,
and properly regulated, the second brood will appear
in about the same time as the first.
Reaumur tried some experiments, still more inge-
nious, with chrysalides, which were suggested by the
effects produced by birds sitting upon their eggs in
order to hatch them, He concluded, that if chry-
310 INSECT TRANSFORMATIONS.
salides were placed under a sitting bird, they would
be matured in a similar way as he had found them
to be in the green-house. The difficulty was to pre-
vent them from being bruised and crushed by the
bird, as they are much softer and more easily injured
than eggs. This he obviated by enclosing them in
hollow glass balls about the size of a hen's egg, which
at the same time as readily deceived the bird as a piece
of chalk passes with the eggs set to hatch under a hen.
The chrysalides which he first tried were those of the
small tortoiseshell butterfly (Vanessa Urticce), eight
of which, attached to square pieces of paper, were sus-
pended within the glass egg as near to each other as
possible, and placed under a hen on the 22d of June.
The aperture of the glass egg was closed, but in such
a manner as to leave a communication with the ex-
ternal air. The effect of the heat manifested itself
the first day, in the moisture exhaled from the chrysa-
lides, all the interior of the glass being covered with
minute drops of water, which he allowed to evaporate
by unstopping the glass, lest the moisture might spoil
his experiment. When it was dry, he replaced it
under the hen, and he observed no moisture exhaled
on the following days, the chief transpiration having
occurred in the first twenty-four hours. In about
four days the first butterfly that, perhaps, was ever
hatched under a hen made its appearance. He found
four more evolved next morning, and one on the suc-
ceeding day, the 28th of June. Those of the same
brood which were contained in a nurse-box placed in
a window, did not appear before the 5th, and some
not before the 8th of July, which was ten or twelve
days later. Two out of eight of the chrysalides which
had been enclosed in the glass egg died. He made
a similar experiment with the same success upon
several chrysalides of the peacock butterfly ( Vanessa
Jo). With the pupas also of two-winged flies and
EXPERIMENTS ON INSECTS. 311
other insects, he tried all the preceding experiments
with very similar results. The heat communicated to
the glass egg was very considerable, amounting to
31 or 32 of Reaumur's thermometer,* or about 100
Fahr. It was not surprising, therefore, that some of
the pupae perished : we think it more wonderful that
any of them survived.
Reaumur suggests, from these experiments, that
those who are curious in obtaining the productions
of summer during winter, may add to the gaiety
of their forced flowers, by forcing a brood of butter-
flies into life to sport amongst them ; and he records
an instance in which a friend of his at Strasburgh in
this way hatched, by means of a stove, all the pupas
he could obtain. We have in several instances suc-
ceeded in obtaining butterflies in winter, by keeping
chrysalides under glasses on a mantel-piece in a room
with a constant fire; but during the winter of 1829-30,
all which were thus kept died, probably from the fires
required by the unusual severity of the season being
too great for them. Several, on the other hand,
which we found on walls, and which had been ex-
posed to all the rigours of the winter, were disclosed
in due time in a perfect state.
Having thus ascertained that heat produced the
effects which he had anticipated, Reaumur next tried an
opposite series of experiments, by placing chrysalides
in diminished temperatures. He accordingly en-
closed in nurse-boxes a number of pupae formed in
August 1733, and in the following January placed
them in a coal-cellar : their natural period of appear-
ing in the perfect state being July 1734. During the
hot months of this year he went from time to time to
see whether these pupae indicated an approaching
change, but they remained in their original state
during July and August, and continued so till the suc-
f Reaumur, Mem. vol. ii, p. 17.
312 INSECT TRANSFORMATIONS.
ceeding August, 1 735, at the time he was writing this
account, when he found them still living and healthy,
but not transformed into perfect insects. We are not
aware whether he ever published the termination of
the experiment.
In another instance, he placed in a coal-cellar the
pupce of the emperor moth (Saturnia pavonia), about
a fortnight or three weeks before the usual time of
their evolution; and they were in consequence retarded
to five or six weeks later than those of the same
brood which he had kept in his cabinet. The chry-
salides of the large garden white butterfly (Pontia
Brassicce^y when placed in the cellar in January,
appeared two months later than those in the tem-
perature of the atmosphere. A still more decisive
experiment was made with the chrysalides of the
small tortoiseshell butterfly (Vanessa t/r/icce), which
require fourteen days of summer heat to mature
them, and which, when hatched under a hen, had
appeared in four days. Some of these he placed in
the cellar the 12th of June, and they did not appear
till the 2d and 3d of August, about six weeks later
than in their natural temperature.
Reaumur, still haunted by the notion of the ex-
halation of moisture being the only cause of the
development of chrysalides, tried upon them similar
ingenious experiments to those which he had success-
fully made upon eggs, by varnishing them in order to
prevent the escape of moisture. His experiments
upon varnishing eggs have led to a most useful dis-
covery, now extensively acted upon in practice for
the preservation of eggs all over Europe. Those
upon chrysalides, however, were not conducted with
the same degree of acute accuracy. To prevent the
chrysalides from coming to maturity at the usual
time, by preventing the exhalation of their moisture,
he conceived it would be sufficient to varnish over
EXPERIMENTS ON INSECTS. 313
the envelope, taking care to leave the respiratory spi-
racles unobstructed. But it is most obvious, that the
greater part of all the evaporation which occurs must
be through the spiracles, in the same way as a large
proportion of the moisture of the human body passes
off by the breath. The result, however, of Reau-
mur's experiments with the varnished chrysalides was,
that they were developed several weeks later than
when placed in their natural circumstances, which
proves, we think, that the envelope has considerable
influence on the transforrnatory process going on in
the interior, even were we to leave the transpiration of
moisture out of the question.*
We may remark, that the results of these experi-
ments afford interesting illustrations of the torpidity of
both the larger animals and of plants. In the United
States of America, for example, many species of ani-
mals which become torpid in Pennsylvania, and other
more northern parts of the country, remain lively in
the Carolinas, and other southern parts of the conti-
nent. | Mr Gough found that the dormouse may be
prevented from becoming torpid by supplying it plen-
tifully with food; and Dr Reeve, of Norwich, ob-
served the same circumstance in a hedge-hog, which
being kept warm and well fed, showed no disposition
to become torpid even during severe weather. J Pal-
las had a tame marmot, also, which having become
very fat during the summer, showed no disposition to
torpidity, though exposed to a temperature which
threw the whole species into a torpid state in that part
of Siberia. In the vegetable kingdom, again, it is a
very common phenomenon to see plants revive after
exposure to severe frosts. Mr Gough made some in-
* Reaumur, Mem. vol. ii. p. 56.
t Barton, in Amer. Phil, Trans, vol. iv.
$ Reeve on Torpidity, p. 73.
TOL. vi. 27
314 INSECT TRANSFORMATIONS.
genious experiments in proof of this upon several
plants, such as the small duck's meat (Lemna minor),
and the viviparous fescue grass (Festuca vivipara),
which led to the conclusion that they could accommo-
date themselves without perishing to the vicissitudes of
variable situations.*
We observed a no less marked instance than those
recorded by Mr Gough, in a plant of the geranium,
named Prince Leopold (Pelargonium macranlhon^
SWEET), the whole of whose leaves were so hard fro-
zen as to break rather than bend. We immersed the
whole of the plant in cold water, a few degrees above
freezing, till it was thawed, and it recovered so com-
pletely, that not a single frosted spot appeared on any
of the leaves. I
Several extraordinary facts relating to insects prove
that temperature alone will not account for the varia-
tions of the periods of their disclosure. It is stated by
Marsham, that Mr Jones of Chelsea, in one of his ex-
cursions, caught a female of the spotted muslin moth
(Diaphora mendica, STEPHENS), which laid a number
of eggs, and he fed thirty-six of the caterpillars hatch-
ed from these, till they spun their cocoons and be-
came pupae. At the usual season only a third of these
produced moths, and he concluded the rest were dead :
but, to his utter astonishment, twelve more made their
appearance the second season; and the remaining
twelve were evolved the third season, as perfect and
healthy as those which had been first produced. J
The same extraordinary fact has been observed in
the pupa3 of the small egger-moth (Eriogaster lanes-
tris), the greater number of those which spin up
in summer appearing in the succeeding February,
* Manchester Trans, t J R-
t Linn, Trans, vol. x, p. 402.
EXPERIMENTS ON INSECTS. 315
but others of them requiring two, three, and even
four, years.* Meinecken kept several pupas of the
emperor-moth ( Saturnia pavonia) through the winter
in a room heated daily by a stove, and others in a cold
chamber. Some of both these appeared in March,
and others, though evidently healthy, had not ap-
peared in July. J*
It is certain, however, that this is not the natural
order of things, even in this species ; for we have
reared several broods of the species respecting which
the preceding facts are recorded, without having
observed them. In a large brood of the small egger
(Eriogaster lanestris) five or six of the cocoons did
not produce insects, and we consequently anticipated
their appearance next year, but we have now kept
them five years without any change, and therefore
conclude they are dead.J The inference deduced,
however, from the facts observed, is very plausible,
namely, that it is intended by Providence to preserve
the species : for were all the individuals of a brood to
appear in the same season, it might happen to be so
ungenial, particularly in the early months of spring,
as to destroy them before they could deposit their
eggs; whereas, by their appearing in different seasons,
some of them have the chance of coming forth in
mild weather. Yet, perhaps, this may be an unne-
cessary though ingenious refining upon a final cause :
for even in the most ungenial spring weather, there
always occur some fine days, and, further, a brood of
insects does not all appear on one day, but more usually
on many successive days, as may be seen by the experi-
ments of Reaumur recorded at the beginning of this
* Scriba, Journ. i, vol. iii, p. 222 ; and Haworth, Lepidopt.
Brit, vol. i, p. 125.
t Naturf., vol. viii, p. 143. t J. R.
Kirby and Spence, vol. iii, p. 267.
316 INSECT TRANSFORMATIONS.
chapter. In the instance of the clear underwing
(JEgema asiliformis, STEPHENS), we discovered a
brood of above a dozen of the pupae in the trunk of a
black poplar ; but though, from feeding on the wood
of the tree, the caterpillars must have been well pro-
tected from the vicissitudes of the seasons, there was
nearly a month between the appearance of the first
and the last.* This, indeed, is so very common an
occurrence that it is almost superfluous to mention
particular instances.
The moths just mentioned, we may remark, were
only observed to appear about noon ;. and many
other insects are known to emerge from the pupa
only at one particular time of the day, similar to the
flowers, such as the goat's-beard (Tragopogon], and
the night-flowering cereus (Cactus grandiflorus],
which only blow at particular hours. Some insects
are produced at sunrise, others at noon, and others
again only at night. Several species are extremely
regular in their appearance, such as the orange-tip
butterfly (Pontia Cardamines), which is usually seen
about the end of April, varying bu.t few days in the
course of many years. The various species, also, of
May-flies (Ephemerae} are confined in their appear-
ance to two or three days ; and those observed by
Reaumur appear at no other time than between
eight or ten in the evening. Those which we no-
ticed on the Rhine in August, 1829, began to
appear at sunset, and before morning were all dead.
In the great square at Wiesbaden, their bodies were
so thickly strewn about that it seemed as if a shower
of snow had fallen during the night, their wings
being white, and about the size of a broad snow-
flake.t
The pupae of these May-flies, when about to un
* J. R. t J. R,
MODES OF EMERGING FROM PUPjE. 317
dergo their transformation, emerge from their sub-
aqueous galleries and come to the surface of the
water. As they must keep their wings dry, the pro-
cess would appear to be one of considerable diffi-
culty ; yet an observer may remark that they perform
it with the utmost ease. In the instance of the gnat,
this process of emerging from the water is still more
conspicuous on account of the difference of form in
the pupa and the fly.
About eight or ten days after the larva of a gnat is
transformed into a pupa, it prepares, generally to-
wards noon, for emerging into the air, raising itself
up to the surface so as to elevate its shoulders just
above the level of the water. It has scarcely got into
this position for an instant, when, by swelling the
part of its body above water, the skin cracks between
the two breathing tubes, and immediately the head of
the gnat makes its appearance through the rent.
The shoulders instantly follow, enlarging the breach
so as to render the extrication of the body compara-
tively easy. The most important and indeed indis-
pensable part of the mechanism, is the maintaining
of its upright position so as not to get wetted, which
would spoil its wings and prevent it from flying. Its
chief support is the rugocity of the envelope which it
is throwing off, and which now serves it as a life-boat
till it gets its wings set at liberty and trimmed for
flight. The body of the insect serves this little boat
for a mast, which is raised in a manner similar to
moveable masts in lighters constructed for pass-
ing under a bridge, with this difference, that the
gnat raises its body in an upright direction from the
first. * When the naturalist,' says Reaumur, c ob-
serves how deep the prow of the tiny boat dips into
the water, he becomes anxious for the fate of the
little mariner, particularly if a breeze ripples the
VOL. vi. 27*
318 INSECT TRANSFORMATIONS.
surface, for the least agitation of the air will waft it
rapidly along, since its body performs the duty of a
sail as well as of a mast : but as it bears a much
greater proportion to the little bark than the largest
sail does to a ship, it appears in great danger of
being upset ; and once laid on its side, all is over.
I have sometimes seen the surface of the water
covered with the bodies of gnats which had perished
in this way ; but for the most part all terminates
favourably, and the danger is instantly over.'*
When the gnat has extricated itself all but the tail,
it first stretches out its two fore-legs,| and then the
middle pair, bending them down to feel for the
water, upon which it is able to walk as upon dry
land, the only aquatic faculty which it retains after
having winged its way above the element where it
The gnat (Culex pipitm") escaping from the pupa.
* Mem.,Tol. iv, p. 613.
f Kirby and Spence, by mistake, say it ' draws* these e out
t)f their caseS vol. iii, p. 288.
MODES OF EMERGING FROM PUPJE. 319
spent the first stages of its existence. c It leaves,
says Swammerdam, c its cast skin on the water
where it insensibly decays.'* Reaumur doubts
whether Swammerdam ever actually saw this inte-
resting transformation. We have seen it twice only.
The beautiful pupa formed from the blood worm,
as before described, proceeds in its transformation
much in the same way as the common gnat. But
how, it may be asked, can the insect raise its
shoulders above the surface of the water, than which
it is specifically heavier, and suspend itself there
without motion ? ' By a most singular and beau-
tiful contrivance, which,' says Kirby, c I shall ex-
plain, the more particularly because it has escaped
Reaumur, and, as far as I know, all other entomo-
logical observers. The middle of the back of the
thorax has the property of repelling water, appa-
rently from being covered with some oily secretion.
Hence, as soon as the pupa has once forced this
part of its body above the surface, the water is seen
to retreat from it on all sides, leaving an oval space
in the disk, which is quite dry. Now though the
specific gravity of the pupa is greater than that of
water, it is but so very slightly greater, that the mere
attraction of the air to the dry part of the thorax,
when once exposed to it, is sufficient to retain it at
the surface; just as a small dry needle swims under
similar circumstances. That this is a true solution
of the phenomenon, I am convinced by the result of
several experiments. If, when the pupa is sus-
pended at the surface, a drop of water be let fall
upon the dry portion of the thorax, it instantly sinks
to the bottom,! the thorax, which belongs to the
heaviest half, being the lowest; and if the pupa be
* Part i, p. 156.
t But, if so, we may ask what has become of the power of
the thorax to repel water ? J. R.
320 INSECT TRANSFORMATIONS.
again brought to the surface, so that the fluid is
repelled from its disk, it remains there, without
effort, as before. Just before the exclusion of the
fly ( Chironomus plumosus, MEIGEN), the dry part
of the thorax is seen to split in the middle. The
air enters, and forms a brilliant stratum, resembling
quicksilver, between the body of the insect and its
puparium; and the former pushing forth its head
and fore-legs, like the gnat, rests the latter upon the
water, and in a few seconds extricates itself wholly
from its envelope.'*
The grubs of several of the four-winged water
flies (Phryganidce, STEPHENS), popularly called
case worms and caddis worms, construct a remark-
able apparatus for protecting the pupa during its
state of inactivity and helplessness. So long as it
remains in the grub state it can withdraw itself within
its case of shells, stones, or reed-stems; but as soon as
it feels its change approaching, it contrives additional
security. It weaves, for this purpose, at the entrance
of its gallery, a grating of its singular silk, which
hardens in water and remains indissoluble, as was
first observed by Vallisnieri. The strong threads
are made to cross each other, forming a small
thickish circular plate of brown silk, which becomes
as hard as gum, fitting exactly into the opening,
and placed a little within the margin. One of these
gratings (described by De Geerj is pierced all over
with holes, disposed in concentric circles, separated
by ridges running from the centre to the circum-
ference, though not quite so regularly as the spokes
of a wheel Other ridges, again, are made to tra-
verse the concentric rays, following ihe course of the
circles of holes, in such a manner as to form com-
partments, each having a hole in its centre. t Reau-
mur found that these holes were for the purpose of
* Tntr., iii, p. 290. t De Geer, Mem., vol. ii, p. 519 45;
MODES OF EMERGING FROM PUP.E. 321
breathing, by admitting a current of fresh water, effect-
ed, no doubt, by the spiracles of the pupa; and he
actually saw the grate-work in alternate motion from
convex to concave, as the water passed out and in.
Our motive, however, for introducing a notice of
these structures is for the purpose of explaining the
contrivance by which the pupa makes its exit through
the grating. To effect this, it is provided with a pair
of curved mandibles, which appear to be applied to no
other use, for they are thrown off upon its transform-
ation into a fly, as was observed by Vallisnieri. These
facts may be verified by searching for caddis worms
during the early spring months, as most of them are
transformed in the first part of the summer.
c, Pupa of a case-fly (Phryganea). c <Z, grate-works of the
same at the openings of the cases, greatly magnified. 6, the -
perfect insect.
In the common blow-fly (Musca carnaria*), and
many of the same family, the exit of the perfect insect
from the pupa case is effected by a very different, but
no less admirable contrivance. The head of the per-
fect fly, it may be remarked, is hard and unyielding;
but in the pupa it is soft, and capable of great disten-
322 INSECT TRANSFORMATIONS.
sion. When the insect, therefore, becomes desirous
of escaping from its prison, it blows out the extensile
part of its head like a bladder, alternately pushing it
forward in the form of a muzzle, and swelling it out
at the sides in the form of a ball, till it succeeds in
rupturing the pupa case. As this envelope is too
opaque to see the process distinctly on the outside, it
is necessary to open the pupa just before its transform-
ation, when the movements become obvious. The
same mechanism occurs in the pupae of some of the
fibrous gall flies (Tephrites), for the purpose of dis-
severing the woody fibres which imprison the insects.
In the instance of the thistle gall fly ( Tephriiis Cardui),
Reaumur found that those kept in his study often be-
came too rigid for the insects to force their passage,
and after making repeated efforts they gave up the
task in despair and died.* In the open air this, acci-
dent is prevented by the rain moistening the galls. We
have more than once had occasion to make the same
remark in the woody galls, such as the bedeguar of
the rose, in which the flies have to gnaw for them-
selves a passage, but which they cannot always effect
when the galls are kept through the winter in a dry
room.*)*
In another genus of flies, the pupa does not make
use of its head, but turns round and employs its tail to
force a passage. This may be observed in the pupa
formed from the rat-tailed maggot of the common-
sewer fly (Eristalis tenax, FABRICIUS), which was ob-
served by Reaumur to push off the lid of its pupa case
by means of its tail.
The caterpillar of the clear-wing hawk moth
(JEgcria asiliformis, STEPHENS), before going into
pupa, gnaws away the wood of the poplar tree,
where it is lodged, till it leaves only a plate of it as
* Reaumur, iv, Mem. 8. t J. K.
MODES OF EMERGING FROM PUP-K. 323
thin as writing-paper. The head of this pupa being
obtuse , it cannot of course cut through this wooden
covering, thin as it is, hut can only push against it till
it burst it open, which we have more than once seen it
actually do.* It is enabled to exert considerable force
in this process, by means of the beautifully serrated
structure of its rings, resembling in this respect the
caterpillars of cossus and other wood-borers.
pupse of Cossus, a, and -<2Jg-m, 6, showing the serratures of their
rings.
Lyonnet justly remarks that in the cossus there are
sharp points upon the head for the purpose of making
the first breach, the rest of the body acting as a wedge
to tear open the cocoon. Professor Peck has given a
very interesting account of similar proceedings in the
case of the locust moth ( Cossus Robinice, PECK). * In
the silk moth,' he says, * and all others which I have
had an opportunity to observe, the chrysalis bursts in
the cocoon, and the fluid which surrounded the new
insect in it escaping at the same time, so weakens or
dissolves the fibre and texture of the silk,! that the moth
is able to extricate itself, leaving the chrysalis behind it;
but this is not the manner in the locust moth. After re-
maining till all its parts are fully grown, and it is ready
to quit its prison, a certain quantity of exercise is ne-
cessary to. break the ligaments which attach the moth
+ J. R.
t See some observations on this doctrine, * Insect Architec-
ture,' pages 316, 317, and 195.
324 INSECT TRANSFORMATIONS.
to the shell of the chrysalis, and to loosen the folds of
the abdomen. In taking this exercise, it can only
move the abdomen in various directions; as one side
of the rings is moved forward, the hooks in the serrated
lines take hold of the silk and prevent their sliding
back; the next flexure brings forward the opposite side
of the rings, which are prevented by the points on that
side from slipping back in the same manner, and the
chrysalis is forced out of the slightly- woven extremity
of the cocoon, and through the silk- lined cavity, till it
is protruded for about one-third of its length out of the
opening in the bark and into the air.'*
A no less ingenious contrivance for escape was ob-
served by Bonnet in one of the leaf-rollers, which feeds
on the leaves of young ash trees. It rolls up the leaf
into a cone, and is transformed into a small pupa, re-
sembling a grain of oats. The chamber which it forms
is not only extensive in proportion to the size of the in-
sect, but is so very compact, that it does not appear in
what manner it is to effect its escape. Within the ca-
pacious chamber of t^he leaf it hangs itself up by two
lines, after the manner of a sailor's hammock. But,
previous to this, it gnaws a circular piece half through
the leaf, taking care not to injure the exterior mem-
brane. In order to render this little door easy to be
found, the caterpillar, as if foreseeing that the blind
pupa could not otherwise discover it, fixes one of the
suspensory threads near its margin, guided by which
the insect makes its exit with the utmost ease, for the
head is uniformly swung up by the door thread. "f
A very similar proceeding is recorded of the mi-
nute granary moth (Tinea granelia), which we
have before mentioned as destructive to grain. The
* Peck, quoted by Kirhy and Spence.
t Bonnet. QEuvres, vol. ii, p. 207.
MODES OF EMERGING FROM PUP^E. 325
eggs being laid on the outside of the grain, the
entrance of the caterpillar into the interior is not
larger than a pin's point, and of course entirely use-
less as a passage for the moth ; but, before its trans-
formation into the pupa, it shapes out a door in the
skin of the grain, so that it may be easily broken open
from within, while it appears entire on the outside.
By pushing it accordingly it at once gives way.
A prospective contrivance of the same kind occurs
in the economy of a caterpillar which lives on the
dry pith in the seed heads of the wild teazle (Dipsa-
cus sylvestris). The hole by which the newly hatched
caterpillar enters is so minute, that in some hun-
dreds of teazle heads, containing full-grown ones,
we have never been able to detect it; but its subse-
quent proceedings are easily traced. From the first
it is not contented with the protection afforded by
the walls of the seed head, but always spins a gallery
of thick silk to cover it while. feeding, the outside of
which is generally covered with its ejectamenta. Up
to the period of its approaching change, the walls of
the seed head are left quite enjtire, as it only eats the
dry pith contained in their cavity; but through these
it would be impossible for the moth to make its way,
inasmuch as it is unprovided with mandibles for
gnawing. The provident caterpillar, therefore, takes
care before its change to cut a circular hole into the
teazle at the end of its own silken gallery, through
which the nascent moth may find an easy passage.
Bonnet gives it farther credit for a piece of ingenuity
which we have not been able to verify. After cutting
the hole, he tells us, it carefully fortifies it on the out-
side by amassing the fibres and seeds of the plant in
a loose manner over the hole, to prevent the intrusion
of rs-pacious insects from without ; and he gives a
very minute detail of his discovery of this fortifies^
VOL. vi. 28
326 INSECT TRANSFORMATIONS.
tion.* But we have only to examine the arrange-
ment of the teazle seeds to perceive that he must
have been mistaken. In a dozen specimens now
before us we find that, besides knawing through the
wall, the insect has eaten about an eigth of an inch
into the seeds themselves and the chaff which sur-
rounds them, leaving on the outside the extremities
untouched, but lining the whole with a slight tissue
of silk, the circumstance, no doubt, which misled
Bonnet. As these are extremely common in the
vicinity of London, almost two-thirds of the seed
heads of teazle containing a caterpillar, the pro-
ceedings of the insect may be easily examined.!
A similar prospective contrivance occurs in the in-
stance of a caterpillar which feeds on the cow parsnip
(Heracleum spondylium), and makes a circular hole
in the stem for the exit of the moth.
In all the preceding instances, the pupa is left to
effect its extrication by its own unassisted efforts.
But amidst the variety which claims our admiration
in the economy of insects, we have to notice pro-
ceedings no less remarkable in the case of those
pupae which require extraneous assistance in their
transformations. An instance of this is mentioned
by Kirby and Spence, on the authority of the Hon.
Captain Percy, R. N., who, while he was watching
some female crane flies (Tipulce oleracewl) busily
employed in depositing their eggs amongst the roots
of grass, saw one quitting her pupa case. She had
already, by her own efforts, got her head, shoulders,
and fore-legs disengaged, when two male flies arrived
to assist in her extrication. They immediately laid
hold of her pupa case with their anal forceps and hind-
legs, while with their fore-legs and mouths they
seemed to push her upwards, moving her backwards
* Bonnet, CEuvres, vol. ii, obs. xix. t J. R.
MODES OF EMERGING FROM PUP^E. 327
and forwards, and shifting their hold till she was
entirely extr cated, when they left her to recover her
strength by herself. ( Probably,' say our authors,
* the extreme length of the two pair of hind-legs of,
these animals may render such assistance necessary
for their extrication. 5 ^ We, however, imagine that
Captain Percy's instance was accidental and anoma-
lous; for the insect having already extricated her head,
shoulders, and fore -legs, all the difficulties were sur-
mounted. From the insect being so very common, *
also, the circumstance of such assistance, if it did
happen, must be matter of frequent observation; but
we have witnessed a considerable number of several
species of this family undergo the change without any
assistance whatever.!
The best ascertained case of assistance occurs
among ants, and was first observed by the accurate
Swedish naturalist De Geer, though the best ac-
count of it is given by the younger Huber, ( The
greater part of the pupa?,' says he, ' are inclosed in
a tissue spun by themselves before their change;
but they cannot, like other insects, liberate themselves
from this covering by effecting an opening in it with
their teeth. They have scarcely the power of mov-
ing; their covering is of too compact a texture, and
formed of too strong a silk, to allow of their tearing
it without the assistance of the workers. But how do
these indefatigable attendants ascertain the proper
moment for this process? If they possessed the fa-
culty of hearing, we might imagine they knew the fit
time, from some noise produced in the interior of the
prison by the insects whose development has com-
menced; but there is no indication favouring this
opinion; it is probable they have a knowledge of it
from some slight movements that take place within,
which they ascertain through the medium of their
* Intr. iii, 286. t J. R.
328 INSECT TRANSFORMATIONS.
antennas ; for these organs are endowed with a sensi-
bility, of which it would be difficult to form a just
idea: whatever it be, they are never deceived.
' Let us still follow them in that labour in which
are displayed a zeal and attachment that would justly
merit our attention, even were they the real parents
of these pupae; how much greater then must be our
astonishment, when we consider that they bear no
further relation to them than that of being born under
the same roof. Several males and females lay in
their envelopes in one of the largest cavities of my
glazed ant-hill. The labourer-ants assembled toge-
ther and appeared to be in continual motion around
them. I noticed three or four mounted upon one of
these cocoons, endeavouring to open it with their
teeth at that extremity answering to the head of the
pupa. They began to thin it by tearing away some
threads of silk where they wished to pierce it, and at
length, by dint of pinching and biting this tissue, so
extremely difficult to break, they formed in it a vast
number of apertures. They afterwards attempted to
enlarge these openings, by tearing or drawing away
the silk; but these efforts proving ineffectual, they
passed one of their mandibles into the cocoon through
the apertures they had formed, and by cutting each
thread, one after the other with great patience, at
length effected a passage, of a line in diameter, in the
superior part of the web. They now uncovered the
head and feet of the prisoner, to which they were de-
sirous of giving liberty, but, before they could effect
its release, it was absolutely necessary to enlarge the
opening. For this purpose these guardians cut out
a portion in the longitudinal direction of the cocoon,
with their teeth alone, employing these instruments
as we are in the habit of employing a pair of scissors.
A considerable degree of agitation prevailed in this
part of the ant-hill. A number of labourer-ants were
MODES OF EMERGING FROM PUPJE. 329
occupied in disengaging the winged individual from
its envelope ; they took repose and relieved each
other by turns, evincing great eagerness in seconding
their companions in the task. To expedite the work,
some raised up a little slip cut out in the length of
the cocoon, whilst others drew the insect gently from
its imprisonment. When the ant was extricated from
its enveloping membrane, it was not, like other in-
sects, capable of enjoying its freedom and taking
flight ; it could neither fly, nor walk, nor, without
difficulty, stand ; for the body was still confined by
another membrane, from which it could not by its
own exertions disengage itself.
' In this fresh embarrassment, the labourer-ants
did not forsake it : they removed the satin-like pel-
licle which embraced every part of the body, drew
the antennae gently from their investment, then dis-
engaged the feet and the wings, and lastly the body,
with the abdomen and its peduncle. The insect was
now in a condition to walk and receive nourishment ,
for which it appeared there was urgent need. Tta
first attention, therefore, paid it by the guardians was
that of giving it the food I had placed within their
reach.
* The ants in every part of the ant-hill were occu-
pied in giving liberty to the males, females, and
young labourer-ants, which were still enveloped. On
being disencumbered of their coverings, the rem-
nants were collected and placed aside in one of the
most distant lodges of their habitation; for these in-
sects observe the greatest order and regularity.
Some species of ants remove these shreds to a dis-
tance from the ant-hill, others cover the exterior sur-
face of their nest with them, or collect them in partic-
ular apartments.'*
A. very interesting experiment upon this subject
was tried by Dr J. R. Johnson, of Bristol. ' Among
* Huber on Ants, p. 88.
VOL. vi. 28*
330 INSECT TRANSFORMATIONS,
those ants I kept in confinement,' says he, e I ob-
served that considerable bustle prevailed when any of
the pupae were about to quit the cocoon. For the
most part two or three stationed themselves on
or near each cocoon. From seeing, more than
once, two engaged in the operation, I placed
in a wine-glass, with a little moistened earth,
one of the yellow ants (Formica flava), with
three or four pupa?; the first object with this little
creature was that of excavating a chamber for the
deposition of its treasure. The pupae were then
brought up, and laid on the surface of the earth from
day to day, to receive the sun's warmth. In a few
days I saw the scattered remnants of one of the
cocoons, and the worker, with his assistant, engaged
in giving liberty to the remaining ants. I did not,
at the time, notice whether the pupae were or were
not capable of effecting their own liberation; but ac-
cording to the statement of De Geer, the pupae dies
when neglected by the workers.'*
The latter circumstance is contradicted by the
testimony of Swammerdam, one of the highest
authorities which could be adduced. The species he
describes as flesh-coloured, and he was not a little
surprised that they spun a cocoon like the silk-worm.
1 This web,' he says, ' was of an oval figure, and
wrought with delicate and fine threads about the
body, being of a rusty iron colour, and when I opened
it I found a pupa in the interior. I likewise carried
some of these enclosed pupa? to Amsterdam, which
after some days gnawed their way out of their webs,
and produced some male ants: this happened on the
eighteenth of July.'f It is obvious, therefore, that
at least some species can extricate themselves with-
out assistance; though this seems to be the regular
process.
* Notes to Huber, p. 87.
t Swammerdam, Biblia Nat., vol. i, p. ISO,
MODES OF EMERGING FROM PUP.E. 33*
We might have been led by analogy to suppose
that bees would adopt a similar method of extricating
their young; but observation shows that they do
not, for they break through their cocoon by means of
their mandibles, at the same time forcing their way
through the wax that is fastened down above to the
web and bursting it into several jagged pieces, which
they throw off on all sides. The other bees carry
these broken pieces away, and clear the cells so thor-
oughly as to make them quite smooth and even.
The male, as well as the queen bees, force their way
also out of their cells in the same manner as the
common or working .kind, and all undergo the same
change.* But there is one very remarkable difference
peculiar to the royal cocoons, first observed by the
elder Huber, which well merits to be mentioned.
A hive of bees is so essentially monarchical, that
when more queens than one are produced they ex-
hibit mutual and deadly animosity, which leads them
to destroy one another. When there are several
royal pupse, therefore, in a hive, the first transformed
attacks the rest and stings them to death; though, if
these pupaB were enveloped in complete cocoons, this'
murder could not be perpetrated; for the silk is of
so close a texture, that the sting could not penetrate
it; and if it did, the barbs would stick fast in the
meshes, and the royal assailant, unable to retract her
weapon, would become the victim of her own fury.
In order, therefore, that she may destroy her rivals,
it is necessary for the hinder rings to remain unco-
vered, and on this account it is inferred the royal
grubs spin only imperfect cocoons, open behind, and
enveloping only the head, shoulders, and first ring of
the abdomen.
Huber was exceedingly anxious to discover whe-
ther the royal grubs spun their cocoons imperfect in
consequence of a particular instinct, or of the greater
*Swammerdam, vol. i, p. 187.
332 INSECT TRANSFORMATIONS.
width of the cells preventing them from stretching
the thread up to the top. To ascertain this he dis-
lodged several royal grubs about to spin their
cocoons, and introduced them into glass cells blown
of varying dimensions. ' They soon prepared to
work,' he says, c and commenced by stretching the
fore part of the body in a straight line, while the
other was bent in a curve, thus forming an arc of
which the sides of the cells afforded two points of
support. It next directed the head to such parts of
the cell as it could reach, and carpeted the surface
with a thick bed of silk. I remarked that the threads
were not carried from one side to another, which
would have been impracticable, for the larvae, being
obliged to support themselves, had to keep the pos-
terior rings curved; and the free and moveable part
of the body was not long enough to admit of the
mouth reaching the opposite sides. The first expe-
riments obviated the probability of any particular in-
stinct in the royal larvae, and proved that they spin
incomplete cocoons, because they are forced to do so
by the figure of their cells. But desirous of evidence
still more direct, I put them into cylindrical glass
cells, where I had the satisfaction of seeing them
spin complete cocoons in the same manner as the
larvae of workers. In fine, I put plebeian larvae into
very wide cells, and they left the cocoon open, as is
done by the royal larvcP. I also found that royal
larvae, when lodged in artificial cells, where they can
spin complete cocoons, undergo all their transforma-
tions equally well. Thus the necessity which nature
imposes on them of leaving the cocoon open, is not
on account of their increment; nor does it appear to
have any other object than that of exposing them to
the certainty of perishing by the wounds of their
natural enemy ; an observation truly new and siq-*
gular.'*
* Huber on Bees, p. 133,
SECT. IV. PERFECT INSECTS.
CHAPTER XIV.
Expansion of the Body and Wings in Insects newly transformed'.
THE mechanism by which winged insects, as well as>
birds, are enabled to support themselves in the air, is
one of the most admirable instances of providential
wisdom, to facilitate the locomotion and the distribu-
tion of the smaller animals. The great agent em-
ployed for this purpose is air, which is made to
serve the double purpose of assisting in the assimi-
lation of nutriment by the supply of oxygen and the
removal of carbon, and of diminishing the weight of
the body in order to render it buoyant In birds,
the lungs have several openings communicating with
corresponding air-bags or cells which fill the whole
cavity of the body from the neck downwards, and
into which the air passes and repasses in the pro-
cess of breathing. This is not all: the very bones of
birds are hollowed out with the design of receiving
air from the lungs, from which air-pipes are con-
veyed to the most solid parts of the body, and even
into the quills and plumelets of the feathers, which are
hollow or spongy for its reception. As all these
hollow parts, as well as the cells, are only open on
the side communicating with the lungs, the bird
requires only to take in a full breath to fill and dis-
tend its whole body with air, which, in consequence
of the considerable heat of its body, is rendered much
lighter than the air of the atmosphere. By forcing
this air out of the body again, the weight becomes so
334 INSECT TRANSFORMATIONS.
much increased that birds of large size can dart down
from great heights in the air with astonishing velocity.
In insects a similar mechanism occurs, though it
is more difficult to trace it, on account of the great
minuteness of the several organs; but so far as the
circumstances can be observed, they well merit our
attention. The most remarkable of these is the
expansion of the body and wings on the perfect
insect emerging from the pupa case. A very
striking exemplification of this occurs in the trans-
formation of the ant-lion (Myrmeleon formicarium,)
whose singular stratagems in the grub state are so
familiar to the readers of books on natural history.*
When it is about to change into a pupa it constructs
a cocoon of sand, which it lines with a beautiful
tapestry of silk, the whole being less than half an
inch in diameter, the pupa itself, when rolled up,
filling only a space of about half this dimension.
When it has remained in the cocoon about three
weeks, it breaks through the envelope and emerges to
the outside, as the chrysalides of wood-borers make
their way to the exterior of a tree to facilitate the exit
.of the perfect insect; with this difference, that the
nascent myrmeleon-fly makes use of its mandibles to
gnaw the cocoon. When it has arrived on the out-
side it only requires to expand its wings and body to
complete its transformation. But this is the process
most calculated to excite our admiration; for though
it is not on its emergence more than half an inch in
length, it almost instantaneously stretches out to an
inch and a quarter, while its wings, which did not
exceed the sixth of an inch, acquire an immediate
expansion of nearly three inches.
To the real wonders attending the history of this
remarkable insect, it has been fancifully added, that,
as it has cast off the spoils and cumbersome weight
* See s Insect Architecture,' page 209, &c.
EXPANSION OF PERFECT INSECTS.
335
of its first form, so it is likewise divested of its barbar-
ity and ravenous malignity; but the formidable struc-
ture of its mandibles, as Reaumur justly remarks, evi-
dently disprove this opinion. A lady discovered that
it would eat fruit, and Reaumur actually saw one
munch part of a pear; but he thinks that this is not its
natural food.* Its close resemblance, indeed, to the
dragon-flies (Libellulina,) except in being more slow
in flight, affords a strong analogical indication of its
carnivorous propensities.
c, Afyrmelton formicarium, the fly of the ant-lion, fe, the head
magnified to show the calliper-formed mandibles, c, the pupa,
rf, the pupa escaping from its cocoon.
A still more striking difference of size tnay be
remarked in the pupa and the perfect insect of a lace-
winged fly (Chrysopa Perla, LEACH,) by no means
uncommon near London, and well known by its
golden eyes and green wings. | The cocoon of this
Mem, vol. vi, p. 375,
t Seepage 45,
336 INSECT TRANSFORMATIONS.
insect is not bigger than a small pea, while the fly is
nearly an inch in length, and the expanse of the wings
about two inches.
In some aquatic insects this transformation is the
more conspicuous from the change of element, the
pupa emerging into the dry atmosphere, where the fly
is evolved. In the case of the dragon-flies just men-
tioned, the approaching , change is evinced by the
increasing transparency of the pupa, exhibiting the
growing brilliancy of the large lustrous eyes of the in-
cluded insect, which may be then brought into view
by removing the envelope. At this period it may be
seen removing out of the water to a dry place, such
as a grassy bank or the stems of aquatic plants, into
which it pushes its sharp claws, and remains for a
short time immovable. By the swelling of the
upper part of the body the envelope is soon distended
and burst asunder on the back of the head and
shoulders, and, through the opening, first the head
and then the legs of the perfect fly make their exit,
whilst the empty slough of the legs continues fixed
in its place. After this first part of the process is
accomplished, it hangs down its head and rests for
a space, as if exhausted by previous exertion, or
rather to allow the newly excluded parts to dry and
become mote firm. It next erects itself, and laying
hold of the upper part of the slough with its feet,
pulls the parts still enveloped further out, then
creeping forward by degrees, it disengages the en-
tire body, and again rests for a time immovable.
The wings now begin to expand themselves, and
their plaits and folds become gradually smooth.
The body, also, becomes insensibly larger and
longer, and the limbs acquire their just size and pro-
portions. While the wings are undergoing this
operation of drying and expanding, the insect takes
care to keep them from coming into contact with tho
EXPANSION OF PERFECT INSECTS.
337
A, the dragon-fly, beginning to escape from the pupa; a, the fly; 6,the
pupa case. B, The process further advanced; c, the fly; d, the pupa
case. C, the fly nearly free, and forming an arch; e, the fly;/, the
pupa case. D, the fly bending back its body, so as not to obstruct the
expansion of the wings.
VOL. vi. 29
338 INSECT TRANSFORMATIONS.
body, by bending itself into the form of a crescent;
for if they were obstructed, whilst wet, they could not
afterwards be set to rights.
All these changes are perfected, according to Swam-
merdam, by the force of the circulating fluids and the
air, impelled by respiration, a fact of which, we think,
there cannot be any doubt. It is very seldom, how-
ever, that we can surprise insects at the precise mo-
ment of their transformation, as it is for the most part
very speedily accomplished, for the whole of the pre-
ceding evolutions are usually completed in ten or fif-
teen minutes. ' It happened by mere chance,' says
Swammerdam, 'that I observed them for the first time:
one of these vermicles adhered to a stone-wall in the
river Loire, and it was so softened by the water dash-
ing up against it, that it could only half perfect its
change, so that I took it partly free and partly yet
fixed in the skin. I once afterwards saw this change
in the large kind of dragon-fly (JEshna?) which had
crept to land out of a small lake, and cast its skin sit-
ting in the grass.'*
c, newly-hatched blow-fly magnified, showing the pulpy,
crumpled state of the wings. 6, the wings dry and fully ex-
panded.
* Bibl. Nat., vol. i, p. 98.
EXPANSION OF PERFECT INSECTS. 339
Some species of flies have their wings shortened
very considerably in the pupa state by zig-zag or trans-
verse folds; so that, when newly evolved, it might be
supposed, from their moist and crumpled appearance,
that they could never become so fine, gauzy, and trans-
lucent, as they are actually seen to do. This will be
better understood from the above figures than by de-
scription.
We have taken the preceding examples of expan-
sion of the wings from those insects in which these are
more or less transparent, and consequently the branch-
ing of the tubes (nervures) through them is more obvi-
ous than in moths and butterflies, in which the wings
are covered with feathery scales. It is, however, less
rare to see the latter transformed than the former,
from the greater facility of rearing them, and on that
account, it may be proper to take some notice here
of their transformation. We cannot in this find bet-
ter guides than Swammerdam and the celebrated Italian
anatomist, Malpighi, in his account of the silk-worm.
'At length,' says the latter, ' within four days, the heart
(dorsal vessel) of the silk-worm continues moving slowly,
and the body growing bigger; having thrown off the
outward skin like a slough, the pupa appears a new
creature. The throwing off the old and assuming this
new form, is completed in the space of one minute and
ten seconds; and it is thus done, as I chanced to see
it. The motion of the heart (dorsal vessel) is very
quick at first, and the whole- frame of the body appears
convulsed; so that the several circular folds of the seg-
ments emerge, and by the transverse contraction of the
sides, the external skin is separated from the inner;
hence, upon making an eflhrt, and thrusting the body,
which now appears particularly thick towards the head,
the skin is driven backward and downward; and the
340 INSECT TRANSFORMATIONS.
portions of the windpipe being separated from their ex-
ternal proper orifices, are thrown away with the skin
which is then cast off. By this motion, a cleft or open-
ing is made in the back near the head, and through the
aperture the body makes its way, the skin being by de-
grees drawn back towards the tail. This process is
assisted greatly by a yellow kind of ichor which exudes
from the cavities t>f the skull; and the pupa appears
then free and disengaged.
' While the insect is making its passage out, the
antennae are separated from the body of the pupa,
and are torn, as it were, out of two cavities of the
skull ; and their length, as they become unfolded,
occupies the same^place which the two muscles of the
mandibles ^o^^ty occupied. The wings, also, and
the legs appear to be circumscribed in their limits;
the wings being drawn from their situation near the
fore-legs, and the legs from the lateral parts of the
back. But as these unfolded parts are yet mucous,
they easily stick to each other, and, insensibly grow-
ing dry, they become so closely united that the pupa
appears like one entire garment. Now as these parts
are peculiar to the moths, and are destined for their
use, the nature of the moths seems to be to emerge
sooner from the state of the caterpillar than is com-
monly believed, and also to be earlier implanted
in it; for evidently, in the silk-worm, the beginnings
of the wings may be seen under the second and
third ring of the body, .before the texture of the
web. The antennas are likewise delineated on the
skull, and the web being finished, they have their
own termination; nor will it be improper to suppose
that the new kind of life in the pupa is only a mask
or veil of the moth, which is already perfect within,
the intent of which is, that it should not be struck 01
EXPANSION OF PERFECT INSECTS. 341
destroyed by external injuries, but migbt grow strong
and ripen.'*
While the little creature remains in this condition,
there is produced, as Swammerdam tells us, a violent
agitation in its fluids, so that they are driven from the
internal vessels through the tubes in the wings, which
are likewise supplied with air from the windpipe. The
insect, besides, labours violently with its legs, and all
these motions concurring with the growth of the wings,
it is impossible that the tender skin which covers it
should not at length give way, which it does by burst-
ing in four distinct and regular pieces. When the legs
become disengaged they much assist in freeing the body
and other parts that are yet bound up; at the same time,
the skin on the back flies open and uncovers the wings
and shoulders. The insect, after this, remains for
some time in a state of rest, with its wings drooping
down like wet paper, and its legs fixed in the skin
which it has just cast off, together with the lining of
the windpipe and breathing spiracles. This latter cir-
cumstance enables the insect to take more air into its
body, and thereby renders it the better able to fly, and
perform the other functions dependant on a good sup-
ply of air. In consequence of this the wings expand
so rapidly, that it is by no means easy to trace their
unfolding; for in the space of a few minutes, they in-
crease in dimensions about five-fold. Their spots and
colours at the same time, previously so small as to
be scarcely discernible, become proportionally extend-
ed, so that what but a few minutes before appeared as
a number of confused and indistinct points, acquires
many varied beauties of colour and form. From the
wings extending themselves so suddenly, their soft
wrinkled appearance is, in less than half an hour,
* Malpighi, De Bornbyce.
VOL. vi. 29*
342 INSECT TRANSFORMATIONS.
no longer visible, and the insect becomes fitted tor
flight.*
Kirby, in speaking of the swallow-tailed butterfly
(Papilio Machaori), says, c I had the pleasure of see-
ing it leave its puparium the 16th of May. With great
care I placed it upon my arm, where it kept pacing
about for the space of more than an hour; when all its
parts appearing consolidated and developed, and the
animal perfect in beauty, I vsecured it, though not with-
out great reluctance, for my cabinet it being the only
living specimen of this fine fly I had ever seen. To
observe how gradual, and yet how rapid, was the de-
velopment of the parts and organs, and particularly of
the wings, and the perfect coming forth of the colour
and spots, as the sun gave vigour to it, was a most in-
teresting spectacle. At first, it was unable to elevate
or even move its wings; but in proportion as the aerial
or other 1 uid was forced by the motions of its trunk
into their nervures, their numerous corrugations and
folds gradually yielded to the action till they had gain-
ed their greatest extent, and the film between all the
nervures became tense* The ocelli, and spots and
bars, which appeared at first as but germs or rudiments
of what they were to be, grew with the growing wing,
and shone forth upon its complete expansion in full
magnitude and beauty. 'f
The probable object of the movements which an
insect makes, upon just escaping from the chrysalis,
is to impel the fluids that had been compressed
during its confinement, and more particularly air,
into the various parts of the expanding body and
wings. The wings, it may be remarked, are not, on
the exclusion of the iiioect, folded up as are the long
wings of an earwig (Forficula auricularia) , but are
* Swammerdam, ii, 7, &c. t Intr. iii, 293.
STRUCTURE OF WINGS. 343
of a thick structure and easily expanded. They differ
in this from full-formed wings, which cannot be stretch-
ed a hair's breadth without tearing them; whereas we
have taken the wing of a butterfly on its emerging
from the chrysalis, and extended it to four times its
original expansion. That the fluids of the body are
at this period impelled into the wings, is proved by
an experiment first tried, we believe, by Swammer-
dam, on the wings of bees. < The blood in the bee,'
he says, < is a limpid fluid, as may be observed, if a
little part be at this time cut off from the wings; for
then the fluid exudes from the cut part, appearing, by
reason of the extreme smallness of the blood-vessels,
under the form of little pellucid globules, which in-
sensibly and fyy degrees increase into considerable
little drops.' 'The wings of the bee have likewise
many pulmonary tubes, which, when the nymph is
casting its last skin, have also, together with all the
other parts, once more to throw off their exuviae.
After this, when these tubes are again distended by
the freshly impelled air, and the air-vessels, which
have hitherto been contracted, are inflated and dis-
tended with the same air, it follows that the whole
wing afterwards expands itself, and becomes thrice,
nay, four times larger than it was before. This ex-
pansion of the wings depends, therefore, both upon
the impulsion of the air and of the blood; for at the
same time v;hen the air is impelled into the wings, a
considerable quantity of blood is likewise driven into
the vessels of the wings.' 'The female bees do not,
as the common bees and the male, come forth with
their wings folded up, but expanded and displayed,
and in a state ready for flight. On this account, the
all-wise Author of Nature has provided for them a
more spacious mansion, in which they may expand
their wings conveniently and properly; so that after
they have burst from their cells they may be pre-
344
INSECT TRANSFORMATIONS.
pared for swarming immediately, if there be a necessity
for it, or that the young queen may be in a 'condition
to drive out her royal mother and take her place if there
be occasion.'*
It does not appear, however, that Swammerdam
proved by dissection the simultaneous existence of
air and blood vessels in the wings, but merely infers
this, as Reaumur afterwards did, from the phenomena.
But Jurine has since actually demonstrated that every
vein (nervure} of a wing contains an air-tube, which
originates in the windpipe,, and follows in a serpentine
form, without filling, every branchlet of the nervures.
Those who have not paid attention to this curious sub-
ject have little conception of the great diversity of forms
which are exhibited by the branchings of these nervures,
. not only in different orders, but even in different spe-
cies of insects. They differ, indeed, as much in this
respect as the leaves of plants do in their mode ot
veining.
Wings of insects : or, wing of a beetle ; 6, wing of an earwig;
f, wing of a saw-fly 5 <7, wing of a crane-fly ; e, wing of a com
nion fly (Musca) ; /, wing of a midge (Psychoda).
* Swammerdam, i, 187.
STRUCTURE OF WINGS. 345
In moths and butterflies the nervures are in a great
measure concealed by the feathery scales; but when
these are removed they are rendered apparent, and
appear to resemble in some measure the arrangement
observed in the two-winged flies. To this arrange-
ment there occurs a remarkable exception in the
family of plumed moths (JHucitidce, LEACH), of
which Stephens enumerates twenty-nine British
species. One of the most common of these is the
large white plume (Pterophorus pentadactylus,
LEACH), which may be seen, during the summer, in
hedges and gardens, flitting about like a tuft of down
or a snow-white feather dropt from the breast of the
eider duck. From being slow in its motions it is
easily taken; but if rudely handled all its snowy
plumage will come off. Another of the family, also
very common, is the twenty-plume moth (Alucita
hexadactyla, LEACH), which may be seen from March
a, the twenty-plume moth. 6, the same magnified, c, the white
plume moth.
till October, on windows and the walls of rooms, or,
still more probably, on the leaves of honey-suckles,
346 INSECT TRANSFORMATIONS.
on which its caterpillar feeds. Reaumur, who had
never found the caterpillar, thought that so delicate
an insect could not exist out of doors during the bleak
weather of spring; and concludes that it feeds like
the clothes moth in-doors an instance among hun-
dreds more how frequently our most plausible reason-
ings are far removed from the facts. This moth is so
small that it is not ready to catch the eye of those who
are unacquainted with it, and even when it is found
it requires a magnify ing- glass to perceive all its
beauties.
The movements of insects just escaped from the
chrysalis appear, then, to be analogous in their design
to the restless motions of the young of larger animals.
In Darwin's fanciful language, the accumulation of
excitability in the sensorium impels the creature to
be frisky for the purpose of getting rid of the super-
abundant stimulus; but whatever the exciting cause
may be, we are certain that the final cause and certain
effect is the brisker impulsion of fluids, and particu-
larly air, through the vessels appropriated to their
circulation, and consequently the more perfect nour-
ishment and speedy growth of the several members.
The analogy between the larger animals and insects
is, that the latter, when they have undergone their
last change from the pupa into the perfect insect, never
increase in size, as the former remain stationary soon
after puberty.
We notice this the more readily, as those who are
but little acquainted with insects are exceedingly
apt to think they grow like other animals, and from
this cause commit many mistakes, not perhaps of
great moment, but which in a work like this it may
prove interesting to rectify. c The most common
British butterflies,' it has been remarked, 'most
persons may have observed to be those which are
white; and all these are usually looked upon as
UNIFORM SIZE OF INSECTS. 347
of the same species, differing in nothing, except,
perhaps, in the size; the latter being erroneously
ascribed to difference of age. But the fact is, that
there are a considerable number of species of our
white butterflies, as well as several genera, and pro-
bably more varieties even of these than have yet been
ascertained or described. It is certain, indeed, that
butterflies do not, like the larger animals, increase
in size as they grow^ older; for every individual,
from the moment it becomes a butterfly, continues
invariably of the same size till its death. Butter-
flies, indeed, seldom live longer than a few days, or
at most a few weeks, and during this time they eat
little, except a sip of honey: and since this is so, it
would be absurd to expect that they could increase in
size. ' It must not, however, be understood from this,
that the same species will always measure or weigh
precisely the same; for though this will hold as a
general rule, there are many exceptions, arising from
the accidents the caterpillar may have suffered from
which an individual butterfly originated. It is only
during the caterpillar state that the insect eats vora-
ciously, and grows in proportion; and if it is, during
this stage of its existence, thrown upon short allow-
ance, it cannot acquire the standard magnitude, and
the butterfly will be dwarfed from the first. The
same remarks with respect to growth apply to insects
of every kind, and the fact cannot be better exemplified
than in the uniformity of size in the house fly (Musca
domeslica) among which scarcely one individual in a
thousand will be found to differ a hair's breadth in
dimensions from its fellows.'*
We may add, that there are many flies occasion-
ally found in houses both larger and smaller than the
Musca domestica, but these are of a different spe-
* J. Rennie on the White Butterflies of Britain, Mag. Nat.
Hist, vol. ii, p. 225.
348 INSECT TRANSFORMATIONS.
cies, and not, as is popularly believed, the old or
the young of the house fly; no more than The mid-
summer cockchafer (Zanthcumia solstitialis, LEACH)
is the young of the common cockchafer (Mdolonihn
vulgaris). It would be equally correct to say that
an ass is the young of a blood-horse, or a mouse the
young of a rat. Nor is this mistake confined merely
to popular belief, for we find it not only stated in
books of natural history, but reasons assigned for its
correctness. * It is held by some apiarians,' says
Huish, c that the bee, in emerging from its cell, has
attained its full growth; I would, however, recom-
mend to those gentlemen to try to thrust either a
bee or a drone into one of the breeding-cells, and
he will find that the capacity of their bodies is too
large for the dimensions of the cell.'* This experi-
ment would not, of course, succeed; but that does
not prove the doctrine, for the author does not take
into consideration the great quantity of air by which
the body is distended; and even if this were ex-
pelled by putting the bee under the exhausted receiver
of an air-pump, the wings and other parts, now be-
come dry and rigid, could not be folded up in the
compact manner in which they xisted in the pupa
state.
The fact of the expansion of the wings by the
impulsion of air and fluids into their nervures,
may be illustrated by the accidental circumstances
into which chrysalides may fall. We have men-
tioned in a preceding page, that the thread by which
a chrysalis is suspended may sometimes snap asun-
der. When this happens, and the chrysalis is allowed
to remain, it will not usually produce an insect com-
plete in all its parts; for the side upon which it lies
being pressed against an unyielding substance by its
own weight, instead of hanging lightly suspended
* Huish on Bees, p. 43
DEFORMED INSECTS. 349
by a silken cord, is prevented from becoming duly
expanded, and when the insect is excluded it is found
to be deformed. This might by some be imagined
to be a mere theoretical view deduced from physio-
logical reasoning; but we can prove it by specimens
of moths arid butterflies which we have reared. A
colony of the brown-tail moth (Porthesia auriflua),
which we reared during the summer of 1829, spun in
the corner of a nurse-box a common web of several
chambers for containing the pupae. One of these
chambers being accidentally torn, a pupa fell upon
the earth in the bottom of the box, and in due time a
female moth was produced from it ; but she never
succeeded in expanding her wings, which remained
till her death shrunk, rumpled, and totally useless for
the purpose of flying, though in every other respect
she was full grown, and deposited in the box a group
of fertile eggs, covered with down from her tail as
neatly as was done by her sisters of the same brood.
In the summer of 1825, the chrysalis of a small tor-
toiseshell butterfly ( Vanessa Urticce) lost its hold of
its silken suspensory, and fell upon the pasteboard
bottom of a nurse-box, resting in a sort of angular
position, so that the case of the upper wing on the
left side pressed upon the box with the whole weight
of the chrysalis above it. When the butterfly made
its appearance, it expanded its wings as usual, but
the wing upon which it had rested was not half the
size of the one on the right side which had lain
uppermost. Another of the same brood had by
some cause not grown so large in the caterpillar
state as the rest. It was transformed, notwithstand-
ing, into a chrysalis, which appeared healthy and
well formed; but when the butterfly appeared, though
it did not differ from the usual appearance, its wings
never expanded a single hair's breadth, and remained
VOL. vr, 30
350
INSECT TRANSFORMATIONS.
always in the same state as when it issued from the
chrysalis.*
II
, Vanessa urtigce, with one wing imperfect. 6, brown-tail
moth, Porthesia aunjlua, with shrivelled wings, c, Vanessa urtic<K^
with unexpanded wings.
It is not a little remarkable, that when insects are
evolved from the pupa state, they always discharge
some substance. It is important to remark, that the
matter voided at tliis period by many butterflies ( Va-
nessce, &c,) is of a red colour, resembling blood, while
that of several moths is orange or whitish. It could
not readily be supposed that this should become the
object of superstitious terror, yet so it has been in
more instances than one. MoufFet tells us, from
Sleidan, that in the year 1 553 a prodigious multitude
of butterflies swarmed throughout a great portion of
Germany, and sprinkled plants, leaves, buildings,
clothes, and men, with bloody drops as if it had rained
blood. "f Several historians, indeed, have recorded
showers of blood among the prodigies which have
struck nations -with consternation, as the supposed
omen of the destruction of cities and the overthrow
of empires. About the beginning of July, 1608, one
of these showers of blood was supposed to have fallen
R,
MoufTet, Theatr. Ins. 107.
SHOWERS OF BLOOD EXPLAINED. 351
in the suburbs of Aix, and for many miles around
it, and particularly the walls of a churchyard were
spotted with the blood. This occurrence would, no
doubt, have been chronicled in history as a super-
natural prodigy, had not Aix possessed at this time,
in M. Peiresc, a philosopher, who, in the eager pur-
suit of all kinds of knowledge, had not neglected the
study of insects. It is accordingly related, in the
curious life of Peiresc by Gassendi, that he had,
about the time of the rumoured shower of blood,
happened to find a large chrysalis, the beauty of
which made him preserve it in a box. Some time
after, hearing a noise in the box, he opened it and
found a fine butterfly, which had left upon the bottom
a red stain of considerable magnitude, and apparently
of exactly the same nature with the drops on the stones,
popularly supposed to be blood. He remarked, at
the same time, that there were countless numbers of
butterflies flying about, which confirmed him in the
belief of his having discovered the true cause ; and
this was further corroborated by his finding none of
the red drops in the heart of the city, where the butter-
flies were rarely seen. He also remarked, that the
drops were never on tiles, and seldom on the upper
part of a stone, as they must have been had they
fallen from the heavens, but usually appeared in
cavities and parts protected by some angular projec-
tion. What Peiresc had thus ascertained, he lost
no time in disclosing to many persons of knowledge
and curiosity, who had been puzzling themselves to
account for the circumstance by far-fetched reason-
ings, such as a supposed vapour which had carried
up a supposed red earth into the air that had tinged
the rain ; no less wide of the truth than the popular
superstition which ascribed it to magic, or to the
devil himself* Those who are curious to verify the
* Reaumur, vol. i, p. 638.
352 INSECT TRANSFORMATIONS.
discovery, as we may well call it, of Peiresc, may
easily do so by rearing any of the spinous caterpillars
which feed on the nettle till they are transformed into
the butterfly. We have witnessed the circumstance
in innumerable instances.
It is a curious and interesting probability, that the
crimson snow of the Alpine and Arctic regions, which
has recently excited so much scientific inquiry, should
be referable to a somewhat similar cause, a circum-
stance which will apologize for our taking some no-
tice of it here by way of illustration. According to
Professor Agardh, red snow is very common in all
the alpine districts of Europe, and is probably of the
same nature with that brought from the polar regions
by Captain Ross. Saussure saw it in abundance on
Mont Brevern, in Switzerland, and elsewhere ;
Ramond found it on the Pyrenees ; and Sommerfeldt
in Norway. In March, 1808, the whole country
about Cadone, Belluno, and Eeltri, is reported to
have been covered in a single night with rose-coloured
snow ; and at the same time a similar shower was
witnessed on the mountains of Valtelin, Brescia,
Carinthia, and Tyrol. But the most remarkable red
snow" shower was that which fell on the night between
the 14th and loth of March, 1823, in Calabria,
in Abruzzo, in Tuscany, at Bologna, and through the
whole chain of the Appennines.
Upon the return of Captain Ross from the Polar
expedition some years ago, the specimens of red
snow which he brought home were examined by
three of our most distinguished observers, Wollaston,
Bauer, and Robert Brown, who all came to the
conclusion that it was of a vegetable nature, but
differed as to its botanical characteristics. Dr
Wollaston supposed it to be the seed of some moss ;
Mr Brown was inclined to consider it an algas, re-
lated to Tremella cruenia, a common native plant ;
CAUSE OF RED SNOW. 353
while Mr Bauer thought it was a fungus of the genus
Uredo. Professor Agardh refers it with Brown to
the lowest order of algae, but standing as a distinct
genus upon the very limits of the animal and vegeta-
ble kingdoms. Saussure, indeed, from finding that
the red snow of the Alps gave out, when burnt, a
smell like that of plants, concluded that it was of
vegetable origin, and supposed it to consist of the
farina of some plant, though he could not trace it to
its source. Baron Wrangel, again, who discovered a
production similar or identical with Agardh's Proto-
coccus nivalis growing upon limestone rocks, mentions
that it was easily detached when placed under water,
and in three days it was converted into animated globules
like infusory animalcules, which swam about and were
made prey of by other infusoria. Professor Nees von
Esenbeck of Bonn, is inclined to think that the minute
red globules, of which the Protococcus consists, are the
vegetable state of bodies which had gone through a
previous animal existence.
The Rev. W. Scoresby, on the other hand, conjec-
tures that the red colour of the snow may be traced to
the same cause as the orange-coloured ice of the polar
seas, which arises from innumerable minute animals
belonging to the Radiata, and similar to the Beroe
globidosa of Lamarck. It is about the size of a pin's
head, transparent, and marked with twelve brownish
patches of dots. In olive-green sea water, he esti-
mated 1 10,592 of these in a cubic foot.*
Agardh remarks, that it is agreed upon all hands
that the crimson snow always falls in the night, from
which he infers that it has not been actually seen to
fall. He thinks it is called into existence by the
vivifying power of the sun's light, after its warmth has
caused the snow to dissolve, accompanied by the
* Jameson's Edin. Journ., Jan, 1829, p. 55.
VOL. vi. 30*
354 INSECT TRANSFORMATIONS.
incomprehensible power in white snow of producing a
colour.*
Reaumur says, with much justice, on another oc-
casion, that an ordinary spectator frequently discovers
what has escaped the notice of the best observers,
and so it should seem it has happened in the present
case, the learned naturalists just mentioned having
gone as wide of the facts, as the philosophers at Aix
in accounting for the supposed shower of blood. Mr
Thomas Nicholson, accompanied with two other gen-
tlemen, made an excursion the 24th July, 1821, to
Sowallick Point, near Bushman's Island, in Prince Re-
gent's Bay, in quest of meteoric iron. ' The summit
of the hill,' he says, c forming the point, is covered with
huge masses of granite, whilst the side which forms a
gentle declivity towards the bay was covered with crim-
son snow. It was evident, at first view, that this co-
lour was imparted to the snow by a substance lying on
the surface. This substance lay scattered here and
there in small masses, bearing some resemblance to
powdered cochineal, surrounded by a lighter shade,
which was produced by the colouring matter being
partly dissolved and diffused by the deliquescent snow.
During this examination our hats and upper garments
were observed to be daubed with a substance of a simi-
lar red colour, and a moment's reflection convinced us
that this was the excrement of the little auk ( Uria alle,
TEMMINCK), myriads of which were continually flying
over our heads, having their nests among the loose
masses of granite. A ready explanation of the origin
of the red snow was now presented to us, and not a
doubt remained in the mind of any that this was the
correct one. The snow on the mountains of higher
elevation than the nests of these birds was perfectly
white, and a ravine at a short distance, which was filled
with snow from top to bottom, but which afforded no
* London's Encycl, of Plants, Protococcus.
CAUSE OF RED SNOW. 355
hiding-place for these birds to form their nests, pre-
sented an appearance uniformly white.'*
This testimony seems to be as clear and indisputable
as the explanation given by Peiresc of the ejecta of the
butterflies at Aix. But though it will account, per-
haps, for the red snow of the polar regions, it will not
explain that of the Alps, the Appennines, and the Py-
renees, which are not, so far as we know, visited by
the little auk. Thus the matter at present rests, till
it be elucidated by further observations.
* Mag. of Nat. Hist., vol. ii, p. 322.
CHAPTER XV.
Peculiar Motions of Insects.
NOTHING that has life seems capable of existing
long without motion. The oyster fixed upon the rock
must open and shut its shell, and the most gnarled oak
must wave its branches, otherwise their fluids will stag-
nate, and disease will ensue. In our own case, we
cannot, if we would, put a stop for any length of time
to all our motions. We have the power, indeed, of
interrupting the nictitation of the eyelids; but if we keep
our eyes fixed for a few minutes they become dry and
painful for want of the regular supply of moisture spread
over them by the process of winking. Breathing, again,
being a more important operation, cannot be long in-
terrupted, without serious consequences; and when the
motion of any of the limbs is prevented by the acci-
dental injury of its joint, it usually shrinks and dwin-
dles into less than half its natural magnitude, because
the proper quantity of the nutritive fluids is not impelled
thither in consequence of its deficiency of motion.
We have already seen how indispensable the motions
of insects are to the due expanding of their wings upon
emerging from the pupa state; and several remarkable
circumstances show that, independent of change of
place in search of food or of other localities for their
progeny, motion is necessary to their well-being. At
least there does not seem any other plausible explication
of what we may term stationary motions. Kirby and
Spence's c motions of insects reposing,'* appears to be
a phrase which would not apply, for example, to an ox
chewing the cud, or a cat washing her face with her paw,
motions precisely similar to many of those of insects
* Introd. vol. ii, p. 304.
MOTIONS OF INSECTS. 357
mentioned by them under this head. The mode
adopted by cats of cleaning themselves with their
paws, is, indeed, not a little similar to that of the
house fly (Musca domestica), which, while it is bask-
ing in a window and enjoying the heat of the sun,
may be frequently seefi not only brushing its feet
upon one another to rub jff the dust, but equally
assiduous in cleaning its eyes, head, and corslet with
its fore-legs, while it brushes its wings with its hind-
legs.* At the time of writing this, March, 1830,
we have just witnessed a similar process in a water
measurer (Hydrometra stagnorum, LATR.), which
we had put into a glass containing water, with a
leaf for it to rest upon. Not liking the narrow pool
in the glass so well as the brook at Lee, from which
it had been taken, it began to climb the edges of the
glass, for which its feet were far from being well
adapted, and it slipped at every step ; but, deter-
mined not .to be baulked, after several unsuccessful
trials, it betook itself to the leaf as if to survey the
obstacles before it again attempted the steep ascent.
After deliberating for a moment, the thought seemed
to strike it that its feet were not in the best trim for
climbing ; and it forthwith began with great assiduity
to clean them somewhat in a similar way to the fly
by wiping them upon one another, but with this dif-
ference, that it did not, like the fly, cross its legs from
opposite sides, the length and rigidity of the thighs
preventing such a movement. It did not forget at
the same time to clean with much care its long an-
tennae, in order, no doubt, to fit them the better for
exploring an unknown path. It. spent several mi-
nutes in this preliminary trimming, when it again be-
gan to mount, and we were no less pleased, perhaps,
than itself, to see its perseverance rewarded ; for,
aided either by the greater cleanness of its feet, or by
* See Insect Architecture, p. 368.
358 INSECT TRANSFORMATIONS.
some particles of slime and sand adhering to the
glass, it triumphantly gained the brim, which it began
to perambulate with an apparent air of proud exul-
tation.* This insect is figured at 6, page 382.
The process of cleaning and brushing the legs, as
birds are seen to preen their feathers, is, however,
the most remarkable, though, perhaps, but seldom
taken notice of among spiders. The same process, as
we have recently discovered, is employed by the Pha-
langia. The apparatus for this is admirably con-
trived. In the common garden geometric spider
(Epeira diadem*), the teeth are used as a comb,
the smooth mandible being employed to hold down
the limb while it is slowly drawn between the teeth,
to free it from flue and dust. In some other species,
instead of smooth teeth, there is a thick-set brush
of hairs, which is used in the same manner, and
must be a still more efficient instrument. The former,
if we do not mistake, chiefly occurs among the
geometric spiders, whose webs are meshed and thin ;
while the brush prevails among those which weave
thick webs, such as the red spider (Dysdera ery-
thrina, WALCKENAER), which we found in the cre-
vice of a chalk rock near Erith, in Kent, but which is
by no means common in Britain, though abundant in
France. We kept this one for some time in a glass,
and observed that it spent the greater part of its
time in brushing its legs. The eyes are placed in
form of a horse-shoe. |
It must have struck those who have visited a
menagerie of wild animals, that, even while they are
standing in their cages, they frequently throw their
heads, and also their bodies, into a sort of oscillatory
movement, evidently not for the purpose of getting
through the bars, but to supply the place of their
natural exercise which confinement prevents them
*J. R. tj. R.
MOTIONS OP INSECTS.
359
a, red spider (Dysdera erythrina'). &, the head of the red
spider, magnified c c, the mandibles, fringed on the inside with
hair, d, the eight eyes, in form of a horse-shoe, e, the head of
the garden spider (Aranea diadtma). f f f, the eight eyes-
g g-, the upper mandibles. A, toothed comb.
from taking. Perhaps this may help us to account
for the singular motions of some of the crane flies
(Tipulidce), while stationary upon a window or a
wall, their whole body vibrating alternately outwards
and inwards from the wall, with a pendulum-iike
movement, as rapid, or more so, than the clicking of
a watch. Kirby and Spence say, this is produced by
the weight of their bodies and the elasticity of their
legs; and that, unless it be connected with respira-
tion, it is not easy to say what is its object.* To us
it appears, like the motion of the caged animals just
mentioned, to be for the purpose of exercising them-
selves and of driving the fluids into their long legs,
which may not be effected in the exercise of flying on
account of their legs then remaining almost motion-
less. Others of the same family may be seen hang-
ing from a wall or ceiling by their fore-legs, while the
hind ones are perked out into the air, and moving up
and down in a slow manner, probably to watch against
approaching danger, as they are very timid; and if
the door of the room where they are be hastily opened
or shut, or if any other agitation of the air be pro-
* Intr. ii, 306.
360
INSECT TRANSFORMATIONS.
ducedj they immediately fly off.* The long-legged
spiders, popularly called shepherds and harvest men
(Phalangidce, LEACH), have a similar mode of ele-
vating their legs, particularly the second pair, which
they move about in all directions.
, Phalangium } b, Hydrometra stagnorum, magnified.
It can scarcely have escaped the remark of the
most indifferent observer, that when butterflies (par-
ticularly those of the genus Vanessa] alight during
sunshine on a leaf or a pathway, they flirt their
wings as a lady does her fan, and perhaps, as has
been conjectured, for the similar purpose of cooling
their bodies. But to us it appears more probably with
the design of impelling air into the tubes of their
wings to fit them the better for flight ; for we have
remarked that they uniformly fan their wings when
about to rise, though they had previously remained
motionless for an hour together. A pretty family of
two-winged flies (Syrphidce^) may frequently be
remarked in lanes and on the borders of woods,
hovering on the wing for a considerable time without
shifting a hair's-breadth from their place, though the
motion of their wings is all the while so rapid as to
be almost imperceptible, similar to some moths
(Sphingidce, Plusia gamma &c,) whilst sipping
J. R.
t See p. 4.
See p. 214.
MOTIONS OF OTHER ANIMALS. 361
the honey of flowers. The vibratory motion of the
wings in these instances is only to buoy them up so
as to retain their place ; but the instant they are
alarmed by the approach of danger, they may be
seen to take several long strokes with their wings,
and dart off with the rapidity of lightning. This is
well illustrated by the motions of birds preparatory
to flight, as they may be observed always to take se~
veral deep inspirations, at the same time often rising on
tiptoe, and puffing out and balancing their bodies to
feel whether they have thrown enough air into their
bones and feathers to float them along. Birds of prey
(Raptores, VIGORS) seem to have the greatest power
both of filling their bodies with air and of expelling it
again at pleasure. Hence the kestril (Falco tinnun-
culus) may be seen floating about for a considerable
time without moving a wing, or perhaps drawing a
breath, till it can hold out no longer, when it flutters its
wings rapidly, not for moving to a different place, for
it remains stationary, but to recover its decreasing
buoyancy by inhaling a fresh supply of air. For the
same reason a trout will oscillate its body when losing
ground by the rapidity of a stream. The osprey (Falco
ossifragus\ on the other hand, we have seen, at the
Kyles of Bute and elsewhere, shoot down like a thun-
derbolt from the air into the sea, plunging far into the
water upon a fish she had marked for her prey,* a
movement only to be explained by the rapid expulsion
of the air which had been the chief agent in keeping her
previously afloat in the region of the clouds. Many
birds which prey on smaller game have somewhat simi-
lar methods of poising and balancing their bodies, of
which the water-ouzel ( Cinclus aquations, BECHSTEIN)
* 'Super est Halteetos,' says Pliny, clarissima oculorum
acie, librans ex alto sese, visoque in mari pisce, prasceps in eurn
ruens, et discussia aquis, rapiens.' Hist. JYat.
VOL. VI. 31
362 INSECT TRANSFORMATIONS.
furnishes a good example, putting itself in a constant
state of preparation, jerking its piebald head up and
down as it skips from stone to stone of the brook, to
pounce under water upon the first grub it espies swim-
ming. In the same way the red-breast (Sylvia rube-
cula) pops jerking about when on the look-out for ca-
terpillars; and so habitual does this become, that he
does not fail to go through the mano3uvre when he
pecks up a crumb at the cottage door, as well as when
he pounces upon a caterpillar in the woods, where it is
often indispensable to secure the aim to prevent the
insect putting in force some stratagem of escape.*
We may next turn to a small two-winged fly, which,
though equally common in gardens and elsewhere with
the fanning butterflies (Vanessce) just alluded to, we
can scarcely (considering its size) expect to have at-
tracted the notice of those who pay little attention to
insects. We allude to the vibrating fly ( Seioptera m-
brans, KIRBY), which is not above a third of the size
of the house-fly, but may be known by its shining black
body, scarlet head, and transparent wings, tipped with
black. This tiny little creature whether it trips over
a leaf, or remains stationary basking in the sunshine, is
continually vibrating its wings. < This motion,' says
Kirby, ' I have reason to think, assists its respiration;'
but as he has not stated his reason, we are led, from
an experiment which we tried, to doubt the conclusion.
Having always seen the fly vibrating its wings in the
sunshine only, as if it enjoyed the warmth and rejoiced
in the feeling of existence, we wished to see how it
would comport itself at night, and enclosed one under
an inverted wine-glass for observation. The conjec-
ture which we had formed appeared to be correct; for
though, when moving about the glass, it vibrated its
* J, R.
MOTIONS OF INSECTS. 363
wings as much by candle-light as in the sunshine, pro-
bably from the habit of associating the two movements,
yet, whenever it remained stationary, it kept the wings
motionless. Had the motion been indispensable to re-
spiration, and analogous to the motion of the gills of
fish, or the panting in the anal scale of the water-louse,
(Jlscllus aquaticuSj LEACH), this cessation would not
have taken place at night.
We are, therefore, perhaps justified in concluding
that the vibration of the wings in this little fly is an
indication of being pleased ; in the same way as a
nestling sparrow, when fed by its dam, will half stretch
its wings, and, as Thompson finely expresses it ; will
' Quiver every feather with desire;*
or as a lamb when sucking will vibrate its tail, as well
as the pretty birds popularly termed wagtails (Mola-
ct//ce), when they perambulate the margin of a stream
and find a plentiful banquet of insects to their liking.
It may prove still more interesting, we think, to
turn our attention to some other movements of insects
which seem to be expressive of pleasure when they are
not stationary, and leaving out of consideration, also,
their foraging for food. A familiar instance of what
we allude to occurs in the aerial dances of the tipuli-
dan gnats and some other insects. These are per-
formed not only in summer, but frequently even in
winter, and in the early months of spring, in shelter-
ed places, indeed, such as under trees and hedges, in
lanes, and when a day chances to be finer than usual,
though the mildest day is of course at these seasons
comparatively chill. The most common of these win-
ter dancers is called by Harris the tell-tale (Tricho-
cera hiemalis, MEIGEN), a troop of which may be
occasionally seen gamboling in a sunny nook, though
the ground be covered with snow. When the weather
364 INSECT TRANSFORMATIONS.
is warm and mild, however, the dancing Tipulidce pre-
fer the decline of day; and wo have remarked them
keeping it up as long as we could distinguish them
between the . eye and the waning light of the western
horizon: how much longer they continued to dance
we cannot tell.
It is a very singular fact connected with these gnat
dances, that the company always consists exclusively
of males. This any person who will take the trouble
may verify by enclosing a group of them in a butterfly-
net. If this be not at hand, he may procure good evi-
dence by wetting the hand, and passing it quickly
amongst the thickest of the crowd; when several will
be caught, and will uniformly exhibit the beautifully
fringed or plumed antennae, which in the female are
without the hairs or the plumelets. What it may be,
besides the same delighted and buoyant spirit which
causes lambs to group together in their frolics, that in-
duces those tiny gnats to sport in this manner on the
wing, is, perhaps, inexplicable.
Wordsworth's opinion, though adopted by Kirby
and Spence, is, perhaps, as we shall presently endea-
vour to show, more poetical than correct. His words
are:
* Nor wanting here to entertain the thought,
Creatures that in communities exist,
Less, as might seem, for general guardianship,
Or through dependence upon mutual aid,
Than by participation of delight,
And a strict love of fellowship combined.
What other spirit can it be that prompts
The gilded summer flies to mix and weave
Their sports together in the solar beam,
Or, in the gloom and twilight, hum their joy.'
The Excursion.
The evening gamboling of rooks on the wing,
MOTIONS OF INSECTS. 365
when they return from their more distant excursions
during the autumn, rnay with more certainty be re-
ferred to this cause. White says, they rendezvous
by thousands over Selborne Down, wheeling round
and diving in a playful manner in the air, and when
this ceremony is over, with the last gleam of light,
they retire to the deep beech woods of Tisted and
Kepley. It may not be improper, however, to dis-
tinguish between this and the restless tossing about
and flapping of the wings, often exhibited by rooks
previous to a storm, which more usually occurs in the
morning, and closely resembles the tossing of sea-
birds on the billows during a gale.*
The quickness of the vision of tipulidan gnats, and
the rapiclity as well as the dexterity of their motion,
may be considered not a little remarkable, from the
circumstance of their flying unwetted in a heavy show-
er of rain, whose drops bigger than their own bo-
dies if they fell upon them, must dash them to the
ground ;"f* unless it may be that the drops glide off
their wings as they do off the feathers of a duck, while
the elasticity of their bodies may save them from ac-
cidents, even when they chance to be pelted.
A very pretty species of these choral flies ( Chiro-
nomus aterrimus ME i GEN), is exceedingly common
in the vicinity of London, appeari-ng about the close
of winter, and readily distinguished . by its shining
snow-white wings, rendered more conspicuous by the
contrast of its black body, while the male has his
antennae adorned with beautiful lead-gray plumelets.
Though groups of these may be found sporting on
the borders of woods and near water, even in January,
proving that, though not half the size of the common
gnat (Culex pipiens), they can brave the bleak winds
of winter, yet they often crowd into our apartments,
like many others of the family. We have just been
* J. R. t Kirby and Spence, vol. ii, p. 374.
VOL. vi. 31*
366 INSECT TRANSFORMATIONS.
watching the proceedings of a pair of these elegant
little creatures by candle-light, when they are more
lively and alert than in the sunshine. We were
reading a large quarto book with wide print and very
broad margins, the white colour of which seemed not
only to attract but to deceive them in the same way
as a bird or a blow-fly will mistake a pane of glass
for the ( viewless air,' and dash recklessly against
it. Our little snowy -winged flies, apparently from a
similar mistake, dashed themselves about on the
pages of the book. We have been accustomed, from
boyhood, to see gnats and other insects tumbling
about in a similar manner when we have been read-
ing at night, a circumstance which few of our readers
can have failed to observe; but we always pitied them
on the supposition that it was in consequence of their
heedlessly singeing their wings in the candle, and
thus unfitting themselves to fly. This, no doubt, is a
frequent cause of their falling on a book; but it was
not so with the two flies which we observed, for they
remained quite perfect and uninjured. The most
remarkable circumstance was, that they almost uni-
formly fell on the back, which seems to indicate that
they fly with the back downwards, a mode of flight
not a little singular, though it has an analogy to the
swimming of some aquatic insects Notonectidce,
LEACH). When they felt the paper, they spun round
in circles and half circles with great rapidity, and
evidently not so much for the purpose of getting
upon their feet as of continuing the gyrations they
had been performing while on the wing. This we in-
ferred from their being in no hurry to get up, and
from their continuing, even when they got upon their
feet, to wheel round and round, as if waltzing with
the express design of showing that they could dance
on the * light fantastic toe,' as well as on the wing.
Their circular movement is not peculiar to them,
MOTIONS OF INSECTS. 367
being observable in several others of the family, par-
ticularly in a still smaller fly with black pellucid wings
(Molobrusl)y and not uncommon in summer, whose
extremely rapid motion we have often admired as it
performs its minute gyrations on a leaf or the petal of
a flower.
It was no less remarkable, that the two snowy-
winged gnats just mentioned were male and fe-
male, as the latter is seldom seen, and when the
males swarm upon a window, a single female can
scarcely be found; but though they were flirting
about on the same page, they took not the slightest
notice of one another, and each went through its
gyrations as if unconscious of the other's presence.
The female, besides, contrary to what is usual among
insects, was by far the most alert and agile of the
two; in so much that, though it was early in March,
we at first mistook her for the minute summer fly al-
luded to in last paragraph.*
From all we have observed, we think it probable,
that notwithstanding the apparent sociality of the
dancing gnats (Tipulidce), they do not congregate
in consequence of any gregarious feelings, or for
mutual assistance; but merely because they are pro-
duced in numbers in the same places, and individually
prefer similar haunts. The individual sportive move-
ments of the two snowy-winged flies just described,
which were performed on the contiguous pages of a
book, or severally at the top and bottom of the same
page, prove that they do not consider the presence
of numbers indispensable. This position is farther
illustrated by the proceedings of an insect of a very
different family the whirlwig beetles (Gyrinidce,
LEACH), which may be seen on the surface of every
pool weaving their eccentric dances, and twinkling
their polished corselets in the sun, both in summer
and, as we have remarked, throughout the winter.
* J. R.
368 INSECT TRANSFORMATIONS.
These are most frequently observed frolicking in
parties of from two to a dozen or more; but we
have very frequently seen an individual performing
his gyrations with the same alacrity when alone .as
when mingling with his companions. We conclude,
therefore, that the apparent sociality of these insects
has no closer bond than that of the vultures which
crowd to devour the same carcase, or of the unsocial
sea-birds which congregate near a shoal of fish.*
Kirby and Spence appear to be of a different
opinion: these c little beetles,' say they, ' which
may be seen clustering in groups under warm banks
in every river and every pool, and wheeling round
and round with great velocity; at your approach
dispersing and diving under water, but, as soon as
you retire, resuming their accustomed movements,
seem to be under the influence of the social principle,
and to form their assemblies for no other purpose
than to enjoy together in the sun-shine the mazy
dance. 'f
The following account of the manners of this bee-
tle, by Mr Knapp, is well worth extracting; though
it is much more lively and interesting than strictly
correct :
c Water, quiet, still water, affords a place of action
to a very amusing little fellow ( Gyrinus natator),
which, about the month of April, if the weather be
tolerably mild, we see gamboling upon the surface
of the sheltered pool; and every schoolboy, who has
angled for minnows in the brook, is well acquainted
with this merry swimmer in his shining black
jacket. Retiring in the autumn, and reposing all the
winter in the mud at the bottom of the pond, it
awakens in the spring, rises to the surface, and com-
mences its summer sports.J They associate in small
* J. R. t Intr., vol. ii, p. 4.
$ We have seen them throughout the severe winter of 1 829-
30, sporting on the unfrozen springs at Lee, in Kent. J. R.
MOTIONS OF INSECTS. 369
parties of ten or a dozen, near the bank, where some
little projection forms a bay, or renders the water
particularly tranquil; and here they will circle round
each other without contention, each in his sphere,
and with no apparent object, from morning until
night, with great sprightliness and animation; and so
lightly do they move on the fluid, as to form only
some faint and transient circles on its surface. Very
fond of society, we seldom see them alone, or, if
parted by accident, they soon rejoin their busy com-
panions. One pool commonly affords space for the
amusement of several parties; yet they do not unite
or contend, but perform their cheerful circlings in
separate family associations. If we interfere with
their merriment they seem greatly alarmed, disperse,
or dive to the bottom, where their fears shortly sub-
side, as we soon again see our little merry friends
gamboling as before. This plain, tiny, gliding
water-flea seems a very unlikely creature to arrest
our young attentions; but the boy with his angle has
not often much to engage his notice, and the social
active parties of this nimble swimmer, presenting
themselves at these periods of vacancy, become in-
sensibly familiar to his sight, and by many of us are
not observed in after-life without recalling former
hours, scenes of, perhaps, less anxious days: for
trifles like these, by reason of some association, are
often remembered, when things of greater moment
pass off and leave no trace upon the mind. '*
* The gyrinus,' say Kirby and Spence, * seems
the merriest and most agile of all the inhabitants of
the waves. Wonderful is the velocity with which
they turn round and round, as it were pursuing each
other in incessant circles, sometimes moving in
oblique, and indeed in every other direction. Now
and then they repose on the surface as if fatigued
* Journal of a Naturalist, p. 307^
370 INSECT TRANSFORMATIONS.
with their dances, and desirous of enjoying the full
effect of the sunbeam: if you approach, they are
instantaneously in motion again. Attempt to entrap
them with your net, and they are under the water and
dispersed in a moment. When the danger ceases,
they re-appear and resume their vagaries. Covered
with lucid armour, when the sun shines they look like
little dancing masses of silver and brilliant pearl.*
The gyrations of the whirlwig are equalled in
rapidity by its diving, when its sports are intruded
upon by our approach. Its great quickness of sight,
indeed, is quite surprising; and is to be accounted for
by one of the most striking instances of providential
contrivance with which we are acquainted. Land
animals see indifferently under water, and aquatic
animals imperfectly in air; and an animal with an
eye equally fitted for seeing in water and in air,
can, on account of the great difference of the me-
diums, possess but imperfect vision in either. The
little whirlwig, to obviate this difficulty, is furnished
with two sets of eyes, one pair being placed on the
upper part of the forehead for seeing in air, and
another pair on the under part of the forehead, ex-
actly under the first, and separated from them by a
thin membrane, for seeing in water. As it swims
half submerged, the latter pair of eyes must be
very useful in warning .the insect of approaching
danger, from fishes or rapacious larvae below, while
the former watch with equal keenness the ap-
proach of enemies above. The hind feet are no less
admirably formed for swimming, being broad, thin
and elastic; while the fore feet are constructed to
answer the purpose of hands for the seizing of prey.
The little animal is, besides all these wonderful
organs, furnished with a pair of ample wings for
transporting itself, should the water of its native
* Jntr. vol. ii, p. 372,
MOTIONS OF INSECTS. 371
pool chance to dry up in summer, and force it to
emigrate.
The sporting of butterflies in pairs, trios, or more,
has been looked, upon by some as pugnacious skir-
mishing. * A few of our lepidopterous creatures,'
says Mr Knapp, ' especially the common white
butterflies of our gardens, are contentious animals,
and drive away a rival from their haunts. We see
them progressively ascending into the air, in ardent
unheeding contest; and thus they are observed, cap-
tured, and consumed in a moment by some watchful
bird; but we have few more jealous and pugnacious
than the little elegant blue argus butterfly (Polyom-
matus Jllexis, STEPHENS,) noted and admired by all.
When fully animated it will not suffer any of its
tribe to cross its path, or approach the flower on
which it sits, with impunity; even the large admirable
( Vanessa atalanta^) at these times, it will assail and
drive away. There is another small butterfly, the
copper (Lyccena Phlceas, FABR.,) however, as hand-
some and, perhaps, still more quarrelsome, frequent-
ing too the same station and flowers; and a constant
warfare exists between them. We shall see these
diminutive creatures, whenever they come near each
other, dart into action, and continue buffeting one
another about till one retires from the contest; when
the victor returns in triumph to the station he had
left. Should the enemy again advance, the combat
is renewed; but should a cloud obscure the sun, or
a breeze chill the air, their ardour becomes abated
and contention ceases. The copper butterfly enjoys
a combat even with its kindred. Two of them are
seldom disturbed, when basking on a knot of asters
in September, without mutual strife ensuing. Being
less affected by cold and moisture than the argus,
they remain with us longer, and these contentions
are protracted till late in the autumn. The pugna-
cious disposition of the argus butterfly soon deprives
372 INSECT TRANSFORMATIONS.
it of much of its beauty; and, unless captured soon
after its birth, we find the margins of its wings torn
and jagged, the elegant blue plumage rubbed from the
wings, and the creature become dark and shabby.'*
We are of opinion, on the other hand, that these
butterfly skirmishings are not prompted by testiness
nor jealousy, but by the spirit of gaiety and frolic
the buoyant feelings arising from the air expanded
in their wings , and bodies by the warm sunshine,
causing the living principle to increase even to exu-
berance. Were these, indeed, actual combats among
the males, like those which take place among game-
cocks or ruffs (Tringa pugnax, LINN.,) nature
would probably have furnished them with weapons
suited to such warfare. But butterflies have neither
spurs, claws, nor sharp bills, wherewith to assail an
enemy; and though they might flap one another with
their wings, till their tiny feathers flew about like a
snow-shower, yet we never have observed them do
so, as Mr Knapp's description seems to imply. On
the contrary, they appear actually to take care that
such an accident should not occur while they frisk
about one another, rising, falling, and performing
zig-zag pirouettes in the air, as we see kittens or
puppies do on the ground, in their more clumsy but
no less frolicsome gambols. Did these skirmishes,
besides, originate in rivalry or jealousy, we should
always see the butterflies combating in couples, for we
never see two or three game-cocks set upon an indi-
vidual; but it is by no means uncommon to see three
and we have qbserved as many as five butterflies, all
equally engaged in these supposed battles, and each
bouncing and popping indiscriminately at the others
without ever coming to blows. It seldom happens
that they actually touch one another, however long
they may be at play, a circumstance which of itself
is sufficient to prove our position.
* Journal of a Naturalist, p. 277.
MOTIONS OF INSECTS. 373
A more extraordinary display of insect dancing,
and which in some instances seems better entitled to
the name of a ball, than our own dancing parties,
occurs amongst the day-flies (Ephemeridce) , whose
short-lived existence renders it necessary for them to
make the most of the few hours at their disposal.
The narrative of the observations made by Reaumur
upon this subject is too interesting to admit of much
abridgment. It is not a little singular, he remarks,
that moths, which fly only in the night, and shun the
day, should be precisely those that come to seek the
light in our apartments ; but it is still more wonderful
that the ephemerae which, appearing after sun-set
and dying before sun-rise, are destined never to
behold the dawn of day, should have so strong an
inclination for any luminous object.
It is usually about the middle of August that
the ephemerae of the Seine and Marne are ex-
pected by the fishermen, and when their season is
come they talk of the manna beginning to appear,
calling the insects by this term on account of the
quantity of food for the fish, which falls as the manna
is recorded to have done in the desert. On the
19th of August, Reaumur, having received notice
that the flies had begun to appear, and that millions
of them were coming out of the water, got into his
boat about three hours before sunset ; but after stay-
ing in the boat till eight o'clock without seeing any,
he resolved, as a storm was foreboded, to return.
He had previously detached from the banks of the
river several masses of earth filled with pupae, which
he put into a large tub full of water. His servants,
who were carrying the tub home, had scarcely set it
upon one of the steps of the stairs leading from his
garden to the Marne, when he heard them exclaim,
' What a prodigious number of ephemeras are here !'
He immediately seized one of the torches and ran to
VOL. vi. 32
374 INSECT TRANSFORMATIONS.
the tub, where he found every piece of earth above
the surface of the water swarming with the flies,
some just beginning to quit their old skin, others
preparing to fly, and others already on the wing,
while every where under water they were seen in a
greater or less degree of forwardness. The threaten-
ed storm of rain and lightening at length coming on,
he was compelled to leave the interesting scene ; but,
to prevent the escape of the insects, he had the tub
covered with a cloth. The violence of the rain ceas-
ed in about half an hour, when he returned to the
garden, and as soon as the cloth was removed from
the tub he perceived that the number of the flies was
prodigiously augmented, and continued to increase for
some time as he stod watching them. Many flew
away, and many more were drowned, but the number
which had already undergone their transformation
from the earth in the tub would have been sufficient
to fill it, exclusively of crowds of others which the
light had attracted from a distance. He again spread
the cloth over the tub, and the light was held above
it : immediately the cloth was almost concealed by
the vast multitudes which alighted upon it, and they
might have been taken by handfulls from the candle-
stick. What he had observed, however, at the tub,
was nothing to the scene now exhibited on the banks
of the river, to which he was again attracted by the
exclamations of his gardener.
c The countless numbers,' he says, ' of ephe-
merae which swarmed over the water can neither be
conceived nor expressed. When snow falls thickest
and in the largest flakes, the air is never so com-
pletely full of them as that which we witnessed filled
with ephemerae. I had scarcely remained a few
minutes in one place, when the step on which I stood
was covered in every part with their bodies, from two
to four inches in depth. Near the lowest step, a
MOTIONS OF INSECTS. 375
surface of water, of five or six feet dimensions every
way, was entirely covered with a thick layer of them,
and those which the stream swept away were more
than replaced by the multitudes that were continually
falling. I was repeatedly compelled to abandon my
station, from not being able to bear the shower of
insects, which, not falling perpendicularly like rain,
struck me incessantly and in a manner extremely
uncomfortable, pelting against every part of my face,
and filling my eyes, nose, and mouth almost to suffo-
cation. On this occasion it was no pleasant post to
hold the light, for our torch-bearer had his clothes
covered with the insects in a few moments, which
rushed in from all quarters to overwhelm him.
' The light of the torch gave origin to a spectacle
which enchanted every one who beheld it, and alto-
gether different from a meteorological shower ; even
the most stupid and unobserving of my domestics were
never satisfied with gazing at it. No armillary sphere
was ever formed of so many circular zones in every
possible direction, having the light for their common
centre. Their number seemed to be infinite, crossing
each other in all directions, and in every imaginable
degree and inclination all of which were more or
less oblique. Each of these zones was composed of
an unbroken string of ephemera?, which followed each
other close in the same line as if they had been tied
together head and tail, resembling a piece of silver
ribbon deeply indented on its edges, and consisting
of equal triangles placed end to end so that the
angles of those that followed were supported by the
base of those which preceded, the whole moving
round with incredible velocity. This spectacle was
caused by the wings of the insects, which alone could
be distinguished. Each of these flies, after having
described one or two orbits, fell to the earth, or into
376 INSECT TRANSFORMATIONS.
the water, though not in consequence of having been
burned.'*
It is conjectured by Kirby and Spence, that
Reaumur, though he was unquestionably a most
accurate observer, may have mistaken the rapid
movements of single flies, and the deception of vision
thence arising, for a numerous troop, following one
another in zoned circular lines, a mistake which
they were once upon the point of committing when
observing the dances of certain small flies which
moved in spirals; closer observation, however, proved
that what appeared to be a continuous line of flies,
was produced by the rapid motion of an individual.
Be this as it may, it will not alter the singularity of
the spectacle. Some of our British ephemera? begin
their dances with the dawn, instead of waiting till
sun-set, rising and falling continually over the
meadows in May, sometimes beating the air rapidly
with their wings, and sometimes skimming about like
hawks. | Those again which we observed in August,
rising from the Rhine, did not dance at all, but flew
in a heavy, unsteady, and lumbering manner above
the current of the river. J
In speaking of what appear to be the sports of
insects, we cannot omit taking notice of the very
singular proceedings of some species of ants, which,
at the intervals of busy industry, amuse themselves
with something apparently analogous to our wrest-
ling and racing matches. Bonnet says, he observed
a small species of ants, which employed themselves
in carrying each other on their backs, the rider hold-
ing with his mandibles the neck of his bearer, and
embracing it closely with his legs, the position
* Reaumur, Mem. vol. vi, p. 485.
t Kirby and Spence, vol. ii, p. 373. t J. R.
Bonnet, CEuvres, vol. ii, p. 407.
MOTIONS OF INSECTS. 377
which the renowned John Gilpin may have some-
times been disposed to assume in his famous race
through Edmonton. But though the very palpable
mistakes committed by Bonnet respecting these very
ants* may, perhaps, tend to invalidate his authority
with respect to their riding, we have the undoubted
testimony of both Gould and Huber for their wrest-
lings. c You may frequently,' says Gould, ' per-
ceive one of these ants (Formica rufa, LATR.) run
to and fro with a fellow-labourer in his forceps of
the same species and colony.' Mr Gould observed,
that, after being carried for some time, it was let go
in a friendly manner and received no personal injury.
This amusement is often repeated, particularly among
the hill ants, who are very fond of this sportive
exercise, "f*
It was amongst the same species, that Huber ob-
served similar proceedings, which he has described with
his usual minuteness and accuracy. c I approached,'
he says, ' one day to the formicary of wood ants,
exposed to the sun and sheltered from the north
The ants were heaped upon one another in great
numbers, and appeared to enjoy the temperature on
the surface of the nest. None of them were at work,
and the immense multitude of insects presented the
appearance of a liquid in the state of ebullition, upon
which the eye could scarcely be fixed without diffi-
culty ; but when 1 examined the conduct of each
ant, I saw them approach one another, moving their
antennaB with astonishing rapidity, while they patted
with a slight movement the cheeks of other ants.
After these preliminary gestures which resembled
caressing, they were observed to raise themselves
upright on their hind legs by pairs, struggle together,
seize each other by a mandible, foot, or antenna, and
* Huber on Ants, pref. and pp. 211 and 233.
t Gould on Ants, p. 102, &c.
VOL. vi. 32*
378 INSECT TRANSFORMATIONS.
then immediately relax their hold to recommence the
attack. They fastened upon each other's shoulders,
or bellies, embraced and overthrew each other, then
raised themselves by turns, taking their revenge
without producing any serious mischief. They did not
spurt out their venom as in their combats, nor retain
their opponents with that obstinacy which we observe
in their real quarrels. They presently abandoned
those which they had first seized, and endeavoured to
catch others. I have seen some who were so eager
in these exercises, that they pursued several workers
in succession, and struggled with them a few mo-
ments, the skirmish only terminating when the least
animated, having overthrown his antagonist, succeeded
in escaping and hiding in one of the galleries. In
one place, two ants appeared to be gamboling
about a stalk of grass, turning alternately to avoid
or seize each other, which brought to my recollection
the sport and pastime of young dogs when they rise
on their hind-legs, attempting to bite, overthrow, and
seize each other, without once closing their teeth.
To witness these facts, it is necessary to approach the
ant-hills with much caution, that the ants should
have no idea of our presence ; if they had, they
would cease at the moment their plays or their occu-
pations, would put themselves in a posture of defence,
curve up their tails, and ejaculate their venom."*
* M. P. Huber on Ants, p. 203,
CHAPTER XVI.
Peculiar Locomotions.
THOSE who have attended to the paces of the larger
animals, are well aware of their almost infinite
variety ; but the differences between the heavy tread of
the elephant or the waddling roll of an overgrown
pig, the elegant pace of a blood-horse or the
sprightly trip of an antelope, will bear no comparison
with the infinite diversities observable among the
movements of insects. We look upon the long legs
of the giraffe and the crane as inelegant and dispro-
portionate, how well suited soever they may be to
their mode of life : but what should we think of a
species of giraffe, with legs long enough to enable it
to overtop the tallest trees, so as to browse on their-
tops as oxen do on the grass of a meadow, while it
walked at ease through woods and forests ; or of a
wren or sparrow with legs as long as the hop-poles
among which it prowled to prey upon aphides and
lady-birds. But animals of such descriptions, wildly
imaginary as they must be confessed to be, may be
readily matched in the insect world. The pendulum
crane fly (Tipula motitatrix), formerly mentioned,
as well as the shepherd spider (Phalangium
opilio}, described in the same place, are remarkable
examples of this ; and we have still more striking
instances in the large clouded- winged crane fly
(Tipula gigantea, MEIGEN), popularly termed father
longlegs, or jenny-spinner, their stilted legs enabling
these insects to overtop the grass as they walk in the
meadows, in the same way as our imaginary giraffe
380 INSECT TRANSFORMATIONS.
would overtop the trees in a forest. We have been
more struck with instances of this in some of the
bug tribe, because here it was least to have been
expected. In our earlier entomological researches,
we frequently noticed, upon a white-washed wall, a
very strange looking insect, if insect it might be
called, moving about in the most awkward manner
imaginable. It looked, however, more like a slip of
gray tree bark, not half the breadth of a wheat-straw,
that had been accidentally caught on some straggling
films of spider's web, which allowed it to oscillate
irregularly in the air, than a real living creature, for
the long gossamer legs did not, to the unassisted eye,
appear to move at all, and the slender awkward
body progressed by interrupted jerks (if such
slow motions may be so termed), resembling the
movement of the minute-hand of a clock. The
glass, however, showed that the body was covered by
the folds of four membranous wings, prettily mottled,
which lay in a hollow groove on the back, while the
long slender legs were elegantly ringed with white
It was, in short, one of the numerous family of plant-
bugs (Neides elegans ? CURTIS) which had strayed
from the adjacent garden to the wall. Another
occurred in the same place somewhat similar, but
considerably smaller, and stalked along with equally
awkward jerks, upon only its four hind-legs, while it
kept its two fore-legs, which were greatly shorter,
folded up under its belly, in readiness, probably, to
seize on the first luckless mite or aphis that came in
its way.* The latter appears to be the wandering
plant-bug (Ploiaria vagabunda, SCOPOLI).
Many insects are capable of performing a feat
which no other animal could accomplish without the
aid of the water-shoes lately invented we allude to
walking on the water, as distinct from swimming,
* J. R.
PECULIAR MOTIONS OF INSECTS.
381
a, Ploiaria vagabunda, magnified. 6, Neides elegans^ magnified,
which most, if not all animals, save man, can do
without instruction. The whirlwig beetle (Gyrinus
natator) can scarcely be said either to walk, run, or
swim, for, as we have taken some pains to ascertain,
it appears not to keep its * oary feet' plunged in
the water as it flits about, but strikes smartly out,
and suddenly folds them flat under its belly; on the
same principle as a waterman on the Thames may
be seen to give two or three quick pulls with his oars,
to put way, as he calls it, upon his wherry, and then
perking them up out of the water, lets it skim along
while he rests motionless. Thus does the little
whirlwig glide along the water as if by magic, for
we cannot see its feet moving on account of the
border of the wing cases (elytra) which overlap
them ; no more than we can discern the feet of a swan,
from their dark colour, resembling that of the water,
even when she skims about at a small distance from
the shore.*
Most people must have been amused by observing
the groups of water insects which seem to delight in
* J.R.
382 INSECT TRANSFORMATIONS.
swimming against small streams, and apparently more
for the purpose of maintaining their place than of
making further progress upwards. The most com-
mon of these are two aquatic bugs of different gene-
ra the one (Gerris locustris, LATR.) with a long
blackish body and legs, and white belly, though more
clumsy in form than the water measurer (Hydrometra
stagnorum) formerly mentioned; and the other (Ve-
lia currens, LATR.), with short body and feet,
black, with a red line running along each side. We
have been still more amused with a dark greenish
gray spider (Lycosa Saccata, LATR.), which, when
we approach near its haunts on the margin of a
stream, does not take shelter in the grass, nor in the
holes of the bank, as most of its kindred would do,
but trips away over the water, where it appears to
know instinctively that we cannot so easily pursue it.
This is not, however, the diving water spider (Jlr-
gyroneta aquatica), for though it can dive and remain
under water, it does not seem to relish this, except
when driven to the measure.*
6, Hydrometra stag-riorum, c d, Hydrachna Geographica, Latr.,
front and back view, both magnified, e, Velia rivulorum, Latr.
* J. R.
PECULIAR MOTIONS OF INSECTS. 383
Some of these water insects have such slender feet,
that we can only explain their not sinking in the wa-
ter on the same principle as that of a small needle
floating when very dry and laid exactly level. Others
again have their feet fringed with fine hairs which
buoy them up ; while the tipulidan gnats ( Chironomi)
and other flies, are, perhaps, aided by their wings in
keeping them afloat; for we have observed several
aquatic flies skimming on the surface of the water,
apparently half running, half flying. Linnasus saw
one of these little tipulae, of a black colour, perform-
ing gyrations on the water similar to those of the
whirlwig (Gyrinus): others use their wings as the
swan does, by way of a sail.
Other insects walk both through the water, and at
its bottom, in a similar manner to walking on land,
and not by striking with their feet, as is done in
swimming. It is in this manner that the minute
pretty water- mite (Hydrachna geographica, MUL-
LER), may be seen in every ditch and pond around
London, pacing along, often in company with a still
more showy one (Limnochares holosericea, LATR.),
whose bright scarlet colour renders it very easily re-
cognised, and may readily lead a young naturalist to
suppose that the scarlet satin mite (Trombidiutn
holosericeum, LATR.), so frequent on dry banks in the
spring, has abandoned the land for the water. The
latter, however, is much larger.
The amphibious nature of those winged beetles
which can walk at the bottom of water, is matched,
if not out-rivalled, by the water-ouzel (Cinclus
aquations , BECHSTEIN), which we have repeatedly seen
walk deliberately under water, and continue its pace
for many yards, as if it had been on land.* As this
* J. R.
384 INSECT TRANSFORMATIONS.
little bird lives on water insects and the fry of fish,
its amphibious powers are indispensable.
Some of these aquatic insects, such as the whirlwig,
are so highly polished, that the water will not adhere
to their bodies; while others (Hydrophili, &c,) are
covered below with a thick coating of silky hair, which
repels the water and usually surrounds them with a
globule of air that shines under water like quicksilver.
The spider mentioned above is similarly furnished with
downy hair for the same purpose.
In walking, insects exhibit endless peculiarities.
The hunting spiders, and many of the midges (Psy-
chodce, LATR.), instead of walking straightforwards,
most usually walk obliquely, and often at right-angles
to the line of their own bodies; while most insects
can, when it is necessary, walk directly backwards
with almost as much facility as forwards. When
the centipedes (Scolopendridce, LEACH) walk back-
wards, they only use their four hind-legs, and these,
when they walk in the usual way, are not employed,
but dragged after them like the locked wheel of a mail-
coach in driving down a steep hill. It was first
observed, we believe, by Kirby, that a millepede
common under stones, the bark of trees, and the
hollow stems of decaying plants, and pro vinci ally
called maggy-manyfeet (Jttt*a terrcshis), performs
its serpent-like motion by extending alternate por-
tions of its numerous legs beyond the line of the
body, while those in the intervals preserve a vertical
direction. So long, then, as it keeps moving, little
bunches of the legs are alternately in and out from
one end to the other of its long body, the undulating
line of motion successively beginning at the head and
passing off at the tail.* We may add, that the form
and structure of this insect are admirably adapted
* Intr., vol. ii, p. 309.
PECULIAR MOTIONS OF INSECTS. 385
to its mode of life, it being long and of small dia-
meter, to enable it to thread its way through narrow
holes, while its covering is highly polished to facili-
tate its passage, and so hard as to prevent it being
lacerated by any splinter of wood which it might
chance to encounter, while it is at the same time so
flexible, that it can coil itself up into a circle of very
small diameter. The hardness and the flexibility,
though apparently incompatible, are produced by a
similar contrivance to that of the spine in man the
whole body of the julus being composed of small
hard rings united by flexible joints.*
Instances have occurred in which a sheep or a
cow has come into the worl^ with legs upon its back :
this, of course, is a monstrosity out of the usual course
of nature; but in a very singular insect, the bat-
louse (Nycteribia Hermanni, LEACH), the legs
appear to have their usual place on the back. ' It
transports itself,' says Colonel Montagu, c with
such celerity, from one part of the animal it inhabits
to the opposite and most distant, although obstructed
by the extreme thickness of the fur, that it is not
readily taken.' c When two or three were put into
a small phial, their agility appeared inconceivably
great ; for, as their feet are incapable of fixing upon
so smooth a body, their whole exertion was employed
in laying hold of each other; and in this most curious
struggle, they appeared actually flying in circles:
and when the bottle was reclined, they would fre-
quently pass from one end to the other with astonish-
ing velocity, accompanied by the same gyrations ; if
by accident they escaped each other, they very soon
became motionless ; and as quickly were the whole
put in motion again by the least touch of the bottle
or the movement of an individual. 'f
Many of the beetles run with great velocity, and
* J. R. t Linn. Trans, vol. xi, p. 13.
VOL. vi. 33
386
INSECT TRANSFORMATIONS.
dart off into holes and corners so suddenly, as often
to escape the quickest movements of an insect
hunter. It is remarkable, however, that those swift-
footed insects seldom run far without making a full
pause to reconnoitre their position, as a deer may be
seen to arch his neck from behind a tree to examine
a stranger, and, after tripping off to some distance,
turn round again to take another peep at the intruder.
The same habit is observable among spiders, partic-
ularly the hunters, and those which run about
meadows and the margins of water (Lycosa saccata,
&c.) Some of the mites are still more rapid in their
movements, and we have often admired a very com-
mon one (Gammasus Baccarum, FABR.) which fre-
quents strawberry-beds in gardens, and, as Kirby
and Spence justly say, appears rather to glide or fly
than to use its legs.* Its minuteness adds to the
o
A, Julus tcrrestris. i, the same coiled up. c,
scarabaeus vulgaris). d, Nycteribia Hei
* Intr. vol. ii, p. 311.
oil beetle (P> .
rwuznni.
PECULIAR MOTIONS OF INSECTS. 3&7
surprise produced by its movements, for it is little
larger than a grain of sand, of a pale reddish colour,
with two black dots on the back;- and though the
clods of garden-mould are mountains in comparison
to its size, it gallops over them at a thousand times
greater proportional speed than the swiftest race-
horse.*
As a contrast to the quick moving insects just
mentioned, we may turn for a moment to those which
move very slowly. The hunting spiders, though they
can dart with the rapidity of lightning upon their
prey, yet take care to approach a victim with such
extraordinary caution, that the shadow upon a sun-dial
advances not more imperceptibly, t Some of the
beetles again move very slowly, particularly the one
popularly called the oil-beetle (Proscarabceus vul-
garis, STEPHENS), on account of the oily -looking
fluid which oozes out from it when seized or alarmed.
The unwieldy bulk of this animal makes it almost
painful to look at the efforts it apparently has to
make as it lumbers along. It always reminds us
of those bees which, during autumn, may often be
seen crawling lifelessly upon flowers, as if so over-
gorged with the honey which they had extracted, that
they are unfit to fly. How the oil-beetle becomes
so fat, it is not easy to say, when we consider that it
feeds upon plants, and is seen very early in spring.
After the severe winter of 1 829-30, we found several,
in the beginning of March, feeding on the bulbous-
rooted buttercup (Ranunculus bulbosus], at Charl-
ton, in Kent, and as plump as if there had not been
a day's frost during the winter.
Another very common insect, popularly called the
bloody-nosed beetle ( Timarcha tenebricosa, ME-
GERLE), from its ejecting a red fluid from its mouth
when caught, is one of the very slow walkers; but
* J. R. t Insect Architecture, p. 355.
388 INSECT TRANSFORMATIONS.
it is furnished with feet most admirably contrived for
taking hold of the catch weed (Galium JLpamne),
and other trailing plants, on which it feeds. This
contrivance consists of cushions, formed of a slightly
concave mass of thick soft hair, which both adheres
by its points, and also produces somewhat of a va-
cuum, which enables it to walk as easily with its head
perpendicularly downwards as upwards.
The most perfect contrivance of this kind, however,
occurs in the domestic fly (Musca domestica), and
its congeners, as well as in several other insects.
Few can have failed to remark, that flies walk with
the utmost ease along the ceiling of a room, and no less
so upon a perpendicular looking-glass; and though
this were turned downwards, the flies would not fall
off, but could maintain their position undisturbed
with their backs hanging downwards. The conjectures
devised by naturalists, to account for this singular
circumstance, previous to the ascertaining of the
actual facts, are not a little amusing. c Some sup-
pose,' says the Abbe de la Pluche, ' that when the
fly marches over any polished body, on which neither
her claws nor her points can fasten, she sometimes
compresses her sponge and causes it to evacuate a
fluid, which fixes her in such a manner as prevents
her falling without diminishing the facility of her
progress; but it is much more probable, that the-
sponges correspond with the fleshy balls which ac-
company the claws of dogs and cats,* and that they
enable the fly to proceed with a softer pace, and con-
tribute to the preservation of its claws, whose pointed
extremities would soon be impaired without this
prevention. 't c Its ability to walk on glass/ says
S. Shaw, c proceeds partly from some little rugged-
ness thereon, but chiefly from a tarnish, or dirty
* See Menageries, Lib. of Entertain. Knowl. vol. i, p. 173.
t Sped, de la Nat. vol. i, p. 116.
PECULIAR MOTIONS OF INSECTS. 38^
smoky substance, adhering to the surface; so that,
though the sharp points on the sponges cannot pene-
trate the surface of the glass, it may easily catch hold
of the tarnish.'* This is evidently brorrowed from
Hook. | But it is singular that none of these fanciers
ever took the trouble to ascertain the existence of either
a gluten squeezed out by the fly, or of the smoky tar-
nish on glass. Even the shrewd Reaumur could not
give a satisfactory explanation of the circumstance.
The earliest correct notion on this curious subject
was entertained by Derham, who, upon mentioning
the provision made for insects that hang on smooth
surfaces, says, 'I might here name divers flies and
other insects, who, besides their sharp-hooked nails,
have also skinny palms to their feet to enable them
to stick to glass and other smooth bodies, by means
of the pressure of the atmosphere after the manner
as I have seen boys carry heavy stones with only a
wet piece of leather clapped on the top of the stone. 'J
The justly celebrated Mr White, of Selborne, ap-
parently without the aid of microscopical investiga-
tion, adopted Derham's opinion, adding the interest
ing illustration, that in the decline of the year, when
the flies crowd to windows and become sluggish and
torpid, they are scarcely able to lift their legs, which
seem glued to the glass, where many actually stick till
they die ; whereas they are, during warm weather, so
brisk and alert that they easily overcome the pressure
of the atmosphere.
This singular mechanism, however, is not peculiar
to flies, for some animals, a hundred times as large,
can walk upon glass by the same means. St Pierre
* Nature Displ., vol. iii, p. 98. Lond. 1823,
t Micrographia, p. 170*
t Physico-Theology, vol. ii, p. 194, note (fe), llth ed.
Nat. Hist, of Selborne, vol. ii, p. 274.
VOL. vi. 33*
390 INSECT TRANSFORMATIONS.
mentions * a very small handsome lizard, about a fin-
ger's length, which climbs along the walls, and even
along glass, in pursuit of flies and other insects;'* and
Sir Joseph Banks noticed another lizard, named the
gecko (Lacerta Gecko, LINN.) which could walk
against gravity, and which made him desirous of hav-
ing the subject thoroughly investigated. On mention-
ing it to Sir Everard Home, he and Mr Bauer com-
menced a series of researches, by which they proved
incontrovertibly, that in climbing upon glass, and walk-
ing along the ceilings with the back downwards, a va-
cuum is produced by a particular apparatus in the feet,
sufficient to cause atmospheric pressure upon their ex-
terior surface.
The apparatus in the feet of the fly consists of two
or three membranous suckers connected with the last
joint of the foot by a narrow neck, of a funnel shape,
immediately under the base of each claw, and moveable
in all directions. These suckers are convex above and
hollow below the edges, being margined with minute
serratures, and the hollow portion covered with down.
In order to produce the vacuum and the pressure, these
membranes are separated and expanded, and when the
fly is about to lift its foot, it brings them together, and
folds them up as it were between the two claws. By
means of a common microscope, these interesting
movements may be observed when a fly is confined in
a wine-glass. |
It is a very remarkable analogy, that many flying
insects, as well as many birds, instead of walking,
leap or hop along somewhat in the manner of a
kangaroo or a jerboa. But the most common and
best known instance of a leaping insect, is the flea
(Pulex irritans)) whose wings are, according to
Kirby, obsolescent. The structure of this annoying
* Voyage to the Isle of France, p. 73.
t Philosoph. Trans, for 1816, p. 325.
PECULIAR MOTIONS OF INSECTS.
Feet of the blue-bottle fly, magnified 6400 times. A, a view of the un-
der side of the last joint of the toe, with the two suckers expanded, as
seen when the fly is walking against gravity. B, side of ditto.
Feet of the bibio ftbriiis, (Latr.,) magnified 6400 times. A, the under
*3ide of the last joint of the toe, with the three suckers expanded. B,
side view of ditto.
INSECT TRANSFORMATIONS.
creature is well fitted for its mode of life it being fur-
nished with so tough a skin that it is no easy matter to
crush it, while it is so smooth that it would almost glide
through a pin-hole. The extraordinary muscular power
of the thighs, again, combined with their elasticity, en-
able it to perform most astonishing leaps, as we have
remarked in a preceding page; while its comparative
lightness and the toughness of its skin prevent it from
receiving any injury, from whatever height it may fall.
It is very doubtful, indeed, as it appears to us, whether
it observes the good old proverb of looking before it
leaps, for we have seen fleas leap from the bottom of a
deep pill-box, where they could riot possibly perceive
whither they were leaping.* It may not be out of
place here to mention, that fleas (Pulicidce) undergo
similar transformations to other insects, laying their
eggs at the roots of the hair of animals, the feathers of
birds, or in woollen stuffs. These, in a few days, pro-
duce a minute whitish grub, which, in warm weather
changes to a perfect flea in about six weeks: as may
be verified by whoever will take the trouble of en-
closing some female fleas, which are always the
largest, in glass tubes, and feeding them with flies or
raw beef, as was done by Rosel, De Geer, and many
Flea magnified, to show the muscular structure of the legs.
* J. R.
PECULIAR MOTIONS OF INSECTS. 393
others. Mr Stephens enumerates no less than twelve
species, from which it appears that those found on
the dog, the pigeon, and other animals, are quite
different from the common flea, and it is probable
these will not readily pass from their natural habit to
infest us, as is commonly believed.
The extraordinary power of leaping in grasshoppers
and their congeners is matter of common observa-
tion. The motion is effected by means of very
strong muscles with which the hind thighs are fur-
nished; and it is a similar structure which enables the
frog-hoppers (Cercopidce LEACH), so common on
plants during summer, to perform leaps of extraor-
dinary extent, in which, however, they have likewise
the assistance of their wings. Some species make
use of their faculty of leaping to escape from their
enemies, as well as for the purpose of changing
place, while others use it to spring upon their prey.
Among the former we may mention a family
of small insects (PoduridaZ) LEACH), some of them
inhabiting water or damp places, though most of the
species are found under decaying bark or vegetable re-
fuse. The one that is most likely to attract attention
is a very small gregarious one, the water spring-tail
(Podura aquatica), which may often be seen, during
the summer, crowded upon the rain-water collected
in the footsteps of cattle, the ruts of cart-wheels, or
by the edges of small ponds, and looking precisely
as if one had strewed about a handful of coal-ashes
or gunpowder ; but, though at first glance they .seem
inanimated, closer inspection will show that they are
in active motion, and particularly if they be alarmed
leaping about and upon one another, and on the
water, like so many minute fire- works. Those which
are solitary are much larger, among which we may
mention the velvet spring-tail (Podura holosericea)^
of which we here give a magnified figure, to show
394 INSECT TRANSFORMATIONS.
the spring in the tail, by means of which it leaps,
jerking it downwards and outwards from its body as
the flea does its legs.
Leaping position of the velvet spring-tail, magnified,
Amongst the insects which spring upon their prey
like the cat and the lion, the most commonly observed
is the little hunting spider (Salticus scenicus), whose
zebra stripes of white and brown render it easily-
discovered on our window-frames and palings.*
But all the spiders even those which form webs -
are accustomed to spring in a similar way upon what
they have caught ; and when we are told of the
gigantic American one (My gale avicularia), which
even makes prey of small birds (Trochilidce}, the
necessity of extraordinary agility must be obvious ;
for these tiny birds are described to move with
almost the velocity of light, the eye, notwithstand-
ing the brilliancy of their metallic colours, being
frequently baffled in tracking their flight. The
spider itself, however, being three inches in length,
one and a half in breadth, and eleven inches in the
expansion of its legs, is little less than the bird upon
which it pounces, as may be seen from the following
figure, taken from the splendid work of Madame
Merian upon the insects of Surinam.
All animals which fly are furnished with powerful
muscles for moving their wings, in the same way as
the limbs of those which leap are similarly provided;
* See Insect Architecture, p. 355.
PECULIAR MOTIONS OF INSECTS.
395
Mygale avicularia, from Madame Merian.
and we may, therefore, remark, in passing, that any
invention for enabling men to fly must take the
comparative weakness of our muscles into primary
consideration. Let any one try merely to stretch out
his arm as a hawk, or a swift fly ( Volucella), does its
wings, when hovering apparently motionless in the
air, and the quick recurrence of weariness, speedily
increasing to pain, will afford unequivocal proof of
the apparently exhaustless vigour of their vojitant
muscles, compared with ours. It would be no very
difficult matter to give voluminous illustrations on
this curious subject. A French naturalist, M. Cha-
brier, has actually written an elaborate quarto vo-
lume, on the flight of insects.* Though Chabrier
has unquestionable talents of the first order for re-
s earch, it is unfortunate that he permits his fancy to
travel somewhat beyond the boundaries of fact; and
t o this, no doubt, we are to ascribe his retracting his
* Essai sur le Vol des Insectes, 4to. Paris, 1801.
396 INSECT TRANSFORMATIONS.
former opinions on the flight of insects; yet it might
have been supposed, that in writing so voluminously
on the subject, he had left no point uninvestigated.
Nothing, however, can be more praiseworthy than
the candour (not very common in such cases) with
which Chabrier corrects his own mistake.
In the two-winged flies (Diptera) Chabrier de-
scribes two sets of muscular ribbons for putting the
wings in play the dorsal, placed lengthwise, and
used to lower the wings, and the sterno-dorsal, placed
obliquely across these for raising the wings. In the
dragon-flies (Libellulina), again, the disposition is
somewhat different, the sterna- dorsal muscles being
placed intermediate, while another set of powerful
muscles, called pectoral, are placed lengthwise, and
are inserted immediately into the wings. In his first
work, our author thought these muscles acted sepa-
rately, but he now says they act in concert; and he
is not now inclined to ascribe, as he at first did,
so much influence to the air in the interior of the
body, nor to the spring of the harder parts of the
back and breast. Certainly,' he adds, < the elas-
ticity of these parts, and the re-action of the interior
air have their use : the fluid, particularly, contained
in their numerous vesicles, is, perhaps, very light, and
contributes to reduce the specific gravity of the
insect. Besides, by enveloping the interior organs,
it appears to me intended to protect these against
the violent motions of flight, and to contribute to
the expansion of the chest, dilating immediately
after being compressed by the contraction of the
muscles in the act of raising the wings. '*
It will appear, from this brief abstract, that the
subject is not a little interesting; yet it is not so easy
to throw it into a form likely to be understood by a
general reader. Flying with wings, however, is a
* M. Chabrier in Ann. des Soc. Nat., Avril 1829, p. 505.
PECULIAR MOTIONS OF INSECTS.
397
Magnified views of the muscular ribbons for moving the wings
in Syrphus inanis. , part of the belly. 6, the costo dorsal
muscles, c, d, the sterna dorsal, e, part of the head.
less difficult subject of investigation than flying with-
out wings, as is practised by the gossamer spider
(Jlranea obtextrix, BECHSTEIN), and its congeners.
We do not allude merely to the threads carried out
from a spider by a current of air, till it is fixed and
forms a bridge, along which the creature can pass,
nor to the similar lines which are left to float freely,
in the case of the gossamer, without attachment*
We refer to the power which the spider apparently
possesses of directing its flight. Let any one endea-
vour to catch one of the spiders which may frequently
be seen dropping from the ceiling of a room, the
branch of a tree, or other elevated object, and he will
find it no easy task to lay hold of the little web spin-
* See Insect Architecture, pp. 339-54.
VOL. vi. 34
398 INSECT TRANSFORMATIONS. .
ner, for it will not only drop perpendicularly by
spinning a longer thread (it seldom tries to escape
by remounting), bu.t it will swing itself away from the
approaching hand, in a manner which it seems not a
little difficult to comprehend, for it does not move a
limb to produce an impulse in the air, as the diving
spider (Jlrgyroneta aquatica) does when it moves
through the water. In instances when no escape is
intended, when spiders, even of considerable size,
drop from a height, we have often seen them swing
out of the perpendicular without any apparent aid
from the wind. It is highly probable that this
movement is effected by some internal apparatus
analogous to the swim-bladder of fishes; but at
present we are not aware that anything beyond con-
jecture has been published upon the subject.. We
may state, however, that they cannot in this manner
move far.
Syrphus.
CHAPTER XVII.
Rest of Insects..
MR BRIGHTWELL is reported to have once ob-
served an individual living specimen of Haltica con-
cinna, which appeared to remain motionless on the
same spot of a wall for three successive days;* but
though this is given as something unusual, we have
made similar observations in the case of numerous in-
sects of all orders and families. The continual sta-
tionary appearance, however, is, in most of guch cases,
quite fallacious. To use a familiar illustration, we
might as well think the snail stationary which we see
every day, perhaps for weeks together, coiled up in
the same niche of the garden-wall, as if it were glued
to the spot, and had never moved from it a hair's-
breadth, were it not that the depredations committed
upon a contiguous lettuce, prove that it does not
always sleep, though its excursions from its chosen
niche, as they take place only at night, are seldom, if
ever, observed. Like a very large portion of the
whole insect world, snails always sleep throughout
the day, unless roused by an accidental shower of rain,
which tempts them to banquet on the refreshed
herbage. Upon butterflies, and some other day in-
sects, again, the occurrence of rain or cloudy weather
usually operates like a continuance or a renewal of
night; and this seems to happen even in-doors, where
the air is warm and comparatively dry. We had a
female of the brimstone butterfly (Gonepteryx
Jthamni) in our study, which we were desirous of
* Kirby and Spence, Intr., vol. iv, p. 193.
400 INSECT TRANSFORMATIONS.
having deposite her eggs on a plant of the buckthorn
(Rhamnus frangula), which we had placed in a
garden-pot for this purpose; and we remarked that
she manifested no inclination to move from the same
leaf, except for an hour or two in the forenoon, and
when it was damp or cloudy, not even then. If
disturbed in her repose, she would fall down as if life-
less, and continue her sleep (if sleep it was), without
being awakened by the fall, till her regular period of
animation returned.
We have used the qualifying phrase < if sleep it
was;' because the rest of insects, though correspond-
ing, in the circumstance of remaining without motion,
with the sleep of the larger animals, may not agree
in any other respect, and particularly in the qui-
escence of*the senses. In the important point of
the state of the brain, it does not appear how there
could be any agreement in the phenomenon; as may
be inferred from comparing the structure of insects,
as respects their nerves and blood-vessels, with that
of man.
Insects, though possessed of nerves, have nothing
similar to our brain and spinal cord, the two sources
of our nerves of feeling and of motion, as so beauti-
fully explained by the recent discoveries of Mr Charles
Bel). Instead of this, they have a chain of what are
called ganglia, or bundles of nervous substance, and
from each of these bundles nerves branch out to the
parts contiguous, each ganglion forming the centre
of feeling to the parts to which its nerves run; and
hence it is that insects will live, and (so far as we
can perceive) feel comparatively little general pain
and inconvenience from the loss of their limbs or
even of their heads. Thus the tail of a wasp or a
bee will sting long after it is severed from the body,
and the head of a dragon-fly will eat as voraciously
after it is cut ofF ; as if it had to supply an insatiable
HEST OF INSECTS. 401
stomach, phenomena easily accounted for from the
want of a brain, and from each ganglion having its
own set of nerves. This may be better understood by
looking at the central chain of ganglia in the larva of
the day-fly before figured.*
Insects again differ from man in having no heart
nor circulating blood, at least so far as has hitherto
been discovered. f Dr Carus, of Dresden, is, indeed,
at present endeavouring to establish a claim to the dis-
covery of the^ circulation of the blood in insects ; but
this circulation, which is most probably only partial,
has, we think, been observed by naturalists of a former
age. De Geer,' say Kirby and Spence, ' whose
love of truth and accuracy no one will call in
question, saw the appearance of blood-vessels in
the leg of the larva of a caddis fly (Phryganea,
LINN.), as Lyonnet did in those of a flea,J and in
the transparent thigh of the bird fly ( Ornithomyia,
avicularia) he discovered a pulse like that of an
artery.^ Baker, whose only object was to record
what he saw, speaks of the current of the blood
being remarkably visible in the legs of some small
bugs;|| what he meant by that term is uncer-
tain, but they could not be spiders, which he had
just distinguished. This author has likewise seen
a green fluid passing through the vessels of the wings
of grasshoppers ;TT and M. Chabrier is of opinion
that insects possess the power of propelling a flujd
into the nervures of their wings, and withdrawing it
at pleasure, as they are elevated or depressed;** but
* See page 139.
t See Cuvie'r, Anat. Comp. vol. iv, p. 478, &c. And Mar-
cel de Serres, Mem. du Mus. pour 1819.
Lesser, vol. ii, p. 84, note.
De Geer, vol. ii, p. 505; vol. vi, p. 287.
I! On the Microscope, vol. i, p. 130. TT Ibid.
** Sur le Vol des Insectes.
VOL. vi, 34*
402 INSECT TRANSFORMATIONS.
these two last facts must be accounted for on other
principles, as there is clearly no circulation.'*
The statement recently published by one of these
authors (Mr Spence), respecting the alleged dis-
covery of insect circulation by Dr Carus, is founded
on facts which were shown and explained to him
by the doctor himself. < The first insect,' says
Mr Spence, c to which Dr Carus directed my
attention, was the larva of ephemera vulgata (or an
allied species), in which, near to the bronchioe and
parallel with each side of the body, was very distinctly
visible a constant current, towards the tail, of oblong
globules swimming in a transparent fluid, propelled
with a regular pulsating motion; and on cutting the
body of the larva across near the tail, three globules
were most plainly seen pushed out of the divided
vessels in a distinct mass, which increased at each
pulsation. I cannot express the pleasure which it
gave me, to see thus clearly this ocular demonstra-
tion of one of the most important physiological dis-
coveries of modern times; and my gratification was
heightened by the next object which Dr Carus placed
before his microscope, viz, a specimen of semblis
viridis (the green lace-winged fly,) in which pre-
cisely the same phenomena, but, if possible, more
clearly, were seen in the nervures of the wings and
in the antennae, in both which the constant current
of globules was most apparent; and in the former,
the sudden turning of these globules, at the apex of
the wing, out of the exterior nervure into a central
one, with which it joins and forms an acute angle,
was equally curious and striking. On cutting off the
end of the antennae, precisely the same emission of
globules (which soon assume a greenish tint) took
place as in the former case, forming a mass, which
was increased with a sudden gush at each pulsation.
* Introd. vol. iv, p, 86.
REST OF INSECTS. 403
Dr Cams has observed the same phenomena in the
wings of Semblis bilineata, and in the elytra (wing
cases) of Lampyris noctiluca (the glow worm), and
L. Italica, as well as in the fin-like appendages at the
tail of the larva of Jlgrion puella (the damsel dragon
fly), in which he first made the discovery^ and in
which the circulation is remarkably distinct.'*
We apprehend, as far as we can collect from this
description, that the alleged discovery of Dr Carus
does not advance a step in demonstrating a circu-
lation in insects similar to that of other classes of
animals; for it is to be recollected, that the dorsal
vessel, the only organ in insects analogous to a
heart, although it pulsates irregularly, has no ap-
parent arteries or veins connected with it: and
therefore the impulsions described by De Geer, the
current mentioned by Baker, and the phenomena
exhibited by Carus, furnish no proof whatever of
a general circulatory system, though they appear to
indicate local movements in the fluids of insects,
agreeably to the original views of Qhabrier, or those
of Swammerdam formerly quoted. f
It may appear to some, that the preceding has but
a very remote connexion with the subject immediately
before us; but we shall presently show its con-
nexion with the phenomena of insect sleep. We
agree with Professor Blumenbach, that sleep in man
most probably consists in a diminished or impeded
flow of arterial blood into the brain. For example,
if, by cold feet, a fit of passion, or a heavy supper,
a gush of blood is forced into the brain and stag-
nates there, the consequence will be the snoring
death-like sleep of apoplexy; and the same will
happen, if a blow on the head, or a fever, throws
a quantity of blood upon the brain. Blumenbach
* Spence in Mag. of Nat Hist, Jan. 18SO, p. 49,
t See page 343.
404 INSECT TRANSFORMATIONS.
had ocular demonstration of the fact contended for,
with respect to the diminished flow of blood, in a
man whose brain was exposed by the accidental re-
moval of a part of the skull; for, whenever this man
fell asleep, the brain was seen to shrink and subside,
but the moment he awoke a tide of blood was seen
rushing" through the vessels and swelling the brain.
The same is also proved by the fact> that in madness
and inflammation of the brain, when the blood flows
rapidly, the unhappy sufferer is altogether deprived
of sleep, unless the current of the blood is retarded
by strong doses of opium, or by taking away a large
quantity by the lancet. It will follow, that when the
blood-vessels of the brain are gorged, as well as when
they are not sufficiently full, sleep will be equally
produced. Force more blood into the brain than can
find room to flow, and drowsiness, sleep, perhaps
apoplexy, will follow; diminish the quantity, so that
it may lack force to keep up the current, and sleep
will also come on. *On these principles it is that
thinking, by bestirring the brain and driving thither a
brisker current of blood, prevents sleep; while,
bathing the feet in warm water, eating a moderate
supper, or rubbing the body with a flesh-brush, by
drawing a superabundance of blood to the feet, to the
stomach, or to the skin, will cause sleep. Again, it
is a general law of animated nature, for rest to suc-
ceed fatigue, as temporary insensibility succeeds vivid
sensations. The pain of a burn, for example, comes
and goes alternately; and by holding out the 'arm
from the body, the feeling of fatigue and pain soon
become so insupportable, that rest cannot be dis-
pensed with. Sleep, then, seems to be a general
consequence of this rest after fatigue.
With regard to insects, it is evident that many of
the above facts will not at all apply; for as insects
have neither a heart nor a brain, their sleep cannot
REST OF INSECTS. 405
be proximately caused by a retarded current of blood.
We want data also for determining whether similar
effects are produced upon the senses of insects during
their quiescence, or apparent sleep, as take place in
ourselves. The shutting of the eye-lids, next to
motionless rest, is one of the most obvious charac-
teristics of sleep in man ; but in insects nothing like
this can be observed, because they have nothing
analogous to eye-lids. The senses of insects, indeed,
may not sleep at all and what renders this the more
probable is, that in the case of gnats, crane-flies
(Tipulidcc), moths, butterflies, &c, however long they
may have been observed to be quiescent, or sleeping,
in the same place, they are instantly on the alert at
the approach of danger, though no noise be made to
alarm them.* It may serve to illustrate this state of
wakefulness in the senses of quiescent insects, that
the senses in man do not all sleep in the same degree
of profundity. This very curious fact was first, we
believe, observed by M. Cabanis, who also found
that some of our senses and members go to sleep
sooner than others in proportion, it may be pre-
sumed to their fatigue from their waking exertions,
and to the flow of blood through them. According
to Cabanis, then, the muscles of the legs and arms
are the first to become drowsy, and next those that
sustain the head, which, losing its support, falls for-
ward ; the muscles of the back follow, and it becomes
bent. Among the senses, the eye is the first that
goes to sleep ; and after it the smell, taste, hearing,
and touch, become drowsy in succession. The sense
of touch never sleeps so profoundly as the others,
a fact inferred from our frequent change of position
during sleep, which must be the consequence of
uneasy sensations of touch. Besides this, it is well
known that a slight tickling of the soles of the feet
* J. R.
406 INSECT TRANSFORMATIONS.
will waken a person whom no noise could rouse. In
the order of their awaking again, taste and smell are
always last, and sight appears more difficult to awaken
than hearing ; for a slight noise will often rouse a
sleep-walker, who had borne an intense light on his
unshut eyes, without seeming in the least to feel its
influence.*
The torpidity of insects during winter, which in
some of its circumstances is analogous to sleep, will
require the less to be discussed here, that we have,
under our three former divisions of Eggs, Pupae, and
Larvae, considered it very amply. The number of
insects, indeed, which hybernate in the perfect state
are comparatively few. Of the brimstone butterfly
(Gonepteryz Rhamni), Mr Stephens tells us the se-
cond brood appears in autumn, ' and of the latter,'
he adds, c many individuals of both sexes remain
throughout the winter, and make their appearance on
the first sunny day in spring. I have seen them
sometimes so early as the middle of February, '"j*
The commonly perfect state of the wings in such
cases might, we think, lead to the contrary con-
clusion, that the butterfly has just been evolved
from its chrysalis. Several other species, however,
chiefly of the genus Vanessa, do live through the
winter in the perfect state ; but this, as far as ge-
neral observation extends, can only be affirmed
of the female. Yet will insects bear almost incre-
dible degrees of e>ld with impunity. Out of the
multiplicity of instances of this on record we shall
select two. In Newfoundland, Captain Buchan saw
a lake, which in the evening was entirely still and
frozen over, but as soon as the sun had dissolved the
ice in the morning, it was all in a bustle of anima-
tion, in consequence, as was discovered, of myriads
* Cabanis, Rapports du Physique et Moral,
t Illustrations,, vol. i, p. 9.
REST OF IIs SECTS. 407
of flies let loose, while many still remained < infixed
and frozen round. ' A still stronger instance is men-
tioned by Ellis, in which a large black mass, like
coal or peat upon the hearth, dissolved, when thrown
upon the fire, into a cloud of mosquitoes (Culicidce)*
It has been remarked by most writers upon the
torpidity of warm-blooded animals, that cold does
not seem to be its only cause, and the same appa-
rently holds in the case of insects. Bees, indeed,
which remain semi-torpid during the winter, may be
prematurely animated into activity by the occurrence
of some days of extraordinary mildness in spring ;
but, what is not a little wonderful and inexplicable,
they are not roused by much milder weather when
it occurs before Christmas, on the same principle,
perhaps, that a man is more easily awakened after he
has slept six or seven hours than in the earlier part
of the night. Immediately after the first severe frost
in the winter of 1829-30, we dug down into the
lower chambers of a nest of the wood-ant (Formica
rufa\ at Forest Hill, Kent, which we had thatched
thickly with fern-leaves the preceding November, both
to mark the spot and to protect the ants in winter.
About two feet deep we found the little colonists all
huddled up in contiguous separate chambers, quite
motionless till they- were exposed to the warm sun-
shine, when they began to drag themselves slug-
gishly and reluctantly along. Even upon bringing
some of them into a warm room, they did not awaken
into summer activity, but remained lethargic, un-
willing to move, and refusing to eat, and continued
in the same state of semi-torpidity till their brethren
in the woods began to bestir themselves to repair the
damages caused by the winter storms in the out-
works of their encampments. |
* Quarterly Review, April 1821, p. 200, t J. R.
408 INSECT TRANSFORMATIONS.
The younger Huber has given an interesting ac-
count of the hybernation of ants, which differs in
some particulars from what we have observed of the
wood-ant ; but he speaks of ants in general. The
subject, indeed, derives importance from the popular
opinion, that they amass wheat and other grain as a
winter store, having been refuted by the experiments
of Gould and other accurate observers. * We
have endeavoured,' says M. Huber, * to explain
their preservation, by supposing them to fall into a
state of torpor at this period. They, in fact, be-
came torpid during the intense cold, but when the
season is not very severe, the depth of their nest
guards them from the effects of the frost : they do
not become torpid unless the temperature is reduced
to the second degree of Reaumur under the freezing
point, (27 Fahrenheit.) I have occasionally seen
them walking upon the snow, engaged in their cus-
tomary avocations. In so reduced a temperature,
they would be exposed to the horrors of famine,
were they not supplied with food by the pucerons,
who, by an admirable concurrence of circumstances,
which we cannot attribute to chance, become torpid
at precisely the same degree of cold as the ants, and
recover from this state also at the same time : the
ants, therefore, always find them when they need
them.
' Those ants that do not possess the knowledge of
the mode of assembling these insects, are, at least,
acquainted with their retreat ; they follow them to the
feet of the trees and the branches of the shrubs they
before frequented, and pass at the first degree of frost
along the hedges, following the paths which con-
duct to these insects. They bring back to the re-
public a small quantity of honey ; a very little sufficing
for their support in winter. As soon as the ants
recover from their torpid state, they venture forth to
HEST OF INSECTS, 409
procure their food. The aliment contained in their
stomach is, on their return, equally distributed to
their companions. These juices scarcely evaporate,
during this season, owing to the thickness of the
honey rings investing the body. 1 have known ants
preserve, during a considerable time, their internal
stock of provisions, when they could not impart it to
their companions. When the cold increases in a
gradual manner, (and this is commonly what the
ants experience, who are screened from it by a thick
wall of earth,) they collect and lie upon each other
by thousands, and appear all hooked together. Is
this done in order to provide themselves a little heat ?
I presume this to be the case, but our thermometers
are not sufficiently delicate to indicate if this be really
the fact. 5 *
During the frosts of 1829-30, we opened two
nests of the yellow ant (Formica flav a), in which we
found the inhabitants by no means torpid or inactive,
although not so lively as in summer ; but these
nests were in a peculiarly warm situation, being both
in the old trunks of willows, rendered quite spongy
by the dry-rot, and facing the south-west, where they
had the benefit of every glimpse of sunshine. We
searched with great minuteness for the eggs of the
aphides mentioned by Huber, but without success,
and we cannot account for their means of subsist-
ence, unless they fed on the various insects and crus-
taceous animals which abounded in the trees,
(Onisci, Julidce, &c.) They were also, in both in-
stances, within a yard of a stream of water, to the
vicinity of which we have observed that this species
is partial, and it is not improbable that it may form
an indispensable part of their subsistence. No spe-
cies of ants, indeed, can live without drinking. In
February of the same year, immediately after the
* Huber on Ants, p. 239, See also this volume, pages 113-116.
VOL, vj. 35
410 INSECT TRANSFORMATIONS.
breaking up of the first frost, we also observed num-
bers of the small black ant (Formica fusca) running
about the sunny sides of hedge-banks ; and though
we did not trace them to their winter quarters, we
think it not improbable, from their very early appear-
ance, that they had never been completely torpid.*
The bee is popularly believed to hybernate, the
seven winter sleepers being said to be, * the bat, the
bee, the butterfly, the cuckoo, and the three swallows;'
but, like many of the popular notions on natural his-
tory, this is almost wholly erroneous, for at least, out
of these seven, the four birds certainly do not become
torpid. With respect to the bee, again, we find some
of the most distinguished observers at variance.
Reaumur is an advocate for the popular opinion.
c It has been established,' he says, ' with a wis-
dom, which we cannot but admire, with which
everything in nature has been made and ordained,
that during the greater part of the time in which the
country furnishes nothing to bees, they have no
longer need to eat. The cold which arrests the ve-
getation of plants which deprives our fields and
meadows of their flowers throws the bees into a
state in which nourishment ceases to be necessary to
them ; it keeps them in a sort of torpidity, in which
no transpiration from them takes place, or at least
during which the quantity of what transpires is so
inconsiderable, that it cannot be restored by aliment
without their lives being endangered. In winter,
while it freezes, we may observe without fear the in-
terior of hives that are not of glass ; for we may lay
them on their sides, and even turn them bottom
upwards, without putting any bee into motion. We
see the bees crowded and closely pressed one against
the other ; little space then suffices for them.'!
Again, when mentioning the custom of putting bee-
* J. K. t Mem. v. p. 667.
REST OF INSECTS. 411
hives during the winter into out-houses and cellars,
he says, ' that in such situations, the air, though
more temperate than out of doors, during the greater
part of the winter, is yet sufficiently cold to keep the
bees in that species of torpidity which does away
with the necessity of their eating.'* He also says,
positively, that the milder the weather, the more risk
there is of the bees consuming their honey before the
spring, and dying of hunger ; confirming his posi-
tion by an account of a striking experiment, in
which a hive that he transferred during winter into
his study, where the temperature was usually, in the
day, 10 or 12 of Reaumur's thermometer above
freezing, or 59 Fahrenheit, though the bees were pro-
vided with a plentiful supply of honey, that if they
had been in a garden would have served past the
end of April, had consumed nearly their whole stock
before the end of February. |
But the elder Huber records some observations
directly opposed to these, affirming unequivocally,
that, so far from being torpid in winter, the heat in a
well peopled hive is as high as 25 Reaumur, or 86
Fahrenheit, even when the thermometer in the open
air is several degrees below zero, the heat thus ob-
served being generated in the hive by their clustering
together, and keeping themselves in motion ; and
even in the middle of winter they may be heard
buzzing as they always do when ventilating the
hive, a process which appears to have been origi-
nally discovered by Huber, and of which, on account
of its connexion with the disputed question before us,
we shall give his own description :
f During fine weather,' (in summer), says he, ' a
certain number of bees always appear before the en-
trance of the hive occupied in vibrating their wings,
but still more are found to be engaged in ventilating
* Mem. vol. v, p. 6S2. t Ib. vol. v, p. 668.
412 INSECT TRANSFORMATIONS.
the interior. The ordinary place of ventilation is on
the board ; those outside of the entrance have their
heads towards it ; those within have them in the oppo-
site direction.
* We may affirm that they arrange themselves re-
gularly to ventilate more at ease, thus forming files,
which terminate at the entrance, and sometimes dis-
posed like so many diverging rays. This order is
not uniform, but is probably owing to the necessity
for the ventilating bees giving way to those going
and coming, whose rapid course compels them to
range themselves in a file, to avoid being hurt or
overthrown every instant.
Sometimes above twenty bees ventilate at the-
bottom of a hive, at other times their number is
more circumscribed, and their employment of various
duration. We have seen them engaged in it during
twenty-five minutes, only taking breath, as it were,
by the shortest interruption of the vibration. On
ceasing, they are succeeded by others, so that there
is never any intermission of the buzzing of a popu-
lous hive.
f If under the necessity of ventilating during
winter, being then united near the centre of the mass
towards the top of their dwelling, doubtless the bees 1
perform this important function among vacuities of
the irregular combs, where there is room for their
wings to expand, as at least half an inch is requisite
for them to play freely.
* The ventilation of the bees, or the buzzing
which denotes it, seems to me more active during
winter than at any other time. It was easy to prove
that this operation established a current of air ; for
anemometers of light paper or cotton, hung by a
thread, were impelled towards the entrance and re-
pelled from it with equal rapidity. The action on
them never was entirely interrupted, and its force
REST OF INSECTS. 413
appeared proportional to the number of bees fanning
themselves.
* If some cultivators of bees shut up the entrance of
their hives in winter without prejudice to the bees, it
must be considered that the air will penetrate through
the straw composing them. I confided an experiment
on this to M. Burnens, then at a distance from me.
Having closed down a very populous straw hive fast
on its board, he found that a piece of the finest paper,
suspended by a hair before the entrance, oscillated
above an inch off the perpendicular line. He poured
liquid honey through an opening in the top, when a
buzzing soon began, and a tumult increasing within,
several bees departed. The oscillations now became
stronger and more frequent. His experiments were
made at three o'clock,the sun shining and the thermo-
meter in the shade standing at 44V*
Swammerdam also seems to indicate that bees re-
main active during the winter, and in order to enable
them to bear its inclemency, they both fortify their hive
and provide a store of honey. ' The order,' he says,
' in which bees that live in the winter months conduct
themselves is this : they first open the cells and eat the
honey deposited in the lowest part of the hive, ascend-
ing by degrees to the upper parts. This they do in
order to preserve a mutual warmth between them; and
the female deposits her eggs in the little cells as they
are emptied. Therefore I discovered both stock and
nymphs about the beginning of March. Let no one
be surprised at this, since towards the beginning of
August I have seen some thousand eggs enclosed in
the ovary of a female bee; so that it is natural for the
bees at any time of the year to lay their eggs and in-
crease their family.'')"
* Hiiber on Bees, p, 295. t Book of Nature, i, 160,
414 INSECT TRANSFORMATIONS.
John Hunter, whose authority stands as high as any
on record, found a hive to grow lighter in a cold than
in a warm week of winter, and that a hive, from Novem-
ber 10th till February 9th, lost more than four pounds
in weight,* a loss which could not well be ascribed to
evaporation.
These discrepancies among naturalists so distin-
guished as both shrewd and faithful observers, forbid
us, we think, to come to any decided conclusion on the
subject, till further researches and experiments have
been made. It is not improbable, however, that the
truth lies in the middle between the two extremes,
for it is quite accordant with what we know both of in-
sects and other animals, that a .high degree of cold
should render them torpid, while they may continue
active if there should be a sudden degree of warmth.
The following observations by the ingenious Mr Gough,
of Manchester, form an interesting illustration of this
curious subject with respect to another insect.
* Those,' says he, ' who have attended to the man-
ners of the hearth cricket (Acheta domesiica) know
that it passes the hottest part of the summer in sunny
situations, concealed in the crevices of walls and heaps
of rubbish. It quits its summer abode about the end
of August, and fixes its residence by the fireside of
kitchens or cottages, where it multiplies its species, and
is as merry at Christmas as other insects in the dog-
days. Thus do the comforts of a warm hearth afford
the cricket a safe refuge, not from death, but from tem-
porary torpidity, which it can support for a long time,
when deprived by accident of artificial warmth. I came
to the knowledge of this fact,' continues Mr Gough,
* by planting a colony of these insects in a kitchen,
where a constant fire was kept through the summer, but
* Phil. Trans, for 1790, p. 161.
REST OF INSECTS. 415
which is discontinued from November till June y with
the exception of a day once in six or eight weeks. The
crickets were brought from a distance, and let go in
this room, in the beginning of September 1806; here
they increased considerably in the course of two months,
but were not heard or seen after the fire was removed.
Their disappearance led me to conclude that the cold
had killed them; but in this I was mistaken; for a brisk
fire being kept up for a whole day in the winter, the
warmth of it invited my colony from their hiding-place,
but not before the evening; after which they continued
to skip about and chirp the greater part of the following
day, when they again disappeared; being compelled,
by the returning cold, to take refuge in their former re-
treats. They left the chimney corner on the 25th of
May, 1807, after a fit of very hot weather, and revi-
sited their winter residence on the 31st of August.
Here they spent the summer merely, and lie torpid at
present (January 1808) in the'crevices of the chimney,
with the exception of those days on which they are re-
called to a temporary existence by the comforts of a
fire.'*
* Reeve, Essay on the Torpidity of Animals, p. 84.
[The subjeqfcpf Insects will be completed in a Third
Volume, which will comprise many Miscellaneous
Facts that were not capable of being classed under
the heads of 'Insect Architecture,' or l Insect Trans-
formations;' with directions for the collection and
preservation of Insects for purposes of study; and a
popular account of the various Systems of Classifi-
cation.]