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PUBLISHED  UNDER  THE  SUPERINTENDENCE  OF  THE  SOCIETY  FOR 
THE  DIFFUSION  OP  USEFUL  KNOWLEDGE. 


THE    LIBRARY 


ENTERTAINING    KNOWLEDGE. 


INSECT  TRANSFORMATIONS. 


COMMITTEE. 

ChoirnMfl— The  Right  Hon.  LORD  BROUGHAM,  F.ILS.,  Meinb.  Na(. 

Inst,  of  France. 

Vice  CAoJrmon— JOHN  WOOD,  Esq. 

Tretuurer-WILLIAM  TOOKE,  Esq.,   F.R.S. 


W.  Allen,  Esq.,  F.R.  &  R.A.S. 
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R.A.S.,  Hydrographer  tothe 

Admiralty. 
Francis  Boott,  M.D. 
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J.  F.  Davis,  Esq.,  F.R.S. 
H.T.  Dela  BecTie,  Esq.,  F.R.S. 
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B.  F.  Duppa,  Esq. 
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Durham,  D.D. 
Sir    Henry    Ellis,     Prin.    Lib. 

Brit.  Mus. 
T.F.Ellis, Esq.,  A.M.,  F.R.A-S. 
John  EUiotson,  M.D.,  F.R.S. 
George  Evans,  Esq.,  M.P. 
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I.  L.  Goldsmid,  Esq.,  F.R.  and 

R.A.S. 
Francis  Henry  Goldsmid,  Esq. 
B.   Gorapertz,  Esq.,   F.R.  and 

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and  L.S. 
M.  D.  Hill,  Esq. 
Rowland  Hill,  Esq.,  F.R.A.S. 
Bight  Hon.  Sir  J.  C.  Hobhouse, 

Bart,  M.P. 
David  Jardine,  Esq.,  A.M. 


Henry  B.  Ker,  Esq. 
Thomas  Hewitt  Key,  Esq.,  A.M. 
George  C.  Lewis,  Esq.,  A.M. 
Thomas  Henry  Lister.  Esq. 
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F.G.S. 
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H.  Maiden,  Esq.,  A.JI. 
A.T.  Malkin.Esq.,  A.M. 
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M.P. 
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Parnell,  Bt.,  M.P. 
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The  Right    Hon.     Lord    John 

Russell,  M.P. 
Sir  M.  A.  Shee,  P.R.A.,  F.R.S. 
John  Abel  Smith,  Esq.,  M.P. 
The  Right  Hon.  Earl  Spencer. 
John  Tavlor,  Esq.,  F.R.S. 
Dr.  A.  T .  Thomson,  F.L.S. 
Thomas  Vardon,  E»q. 
H.  Wavmouth,Esq. 
J.  Whishaw,  Esq.,  A.M.,  F.R.S. 
The    Hon.    John     Wiottesley. 

A.M.,  F.R.A.S. 
Thomas  Wyse,  Esq.,  M.P. 
J.  A.  Yatee,  Esq.,  M.P. 


TnOUAS  COATES,  Esq.,  Steretar;/,  No.  59,  lincolit'i  Inn  FltUf. 


THE  LIBRARY  OF  ENTERTAINING  KNOJVLEDOE. 


INSECT 


TRANSFORMATIONS. 


LONDON: 
CHARLES  KNIGHT  &  CO.,  LUDGATE  STREET. 


MDCCCXXXVIII. 


LONDON : 

XViuted  by  William  Clowes  and  Sons, 
Stamford  Street. 


I 


UBB 


CONTENTS. 


SECTION  I.— EGGS  OF  INSECTS. 


CHAPTER  I.— Intkoductory. 


Page 

All  insects  come  from  eggs 1 

Curious  experiment  of  Kircher      ......  2 

Virjjil's  receipt  for  making  a  swarm  of  bees         ...  3 

Origin  of  these  ancient  errors 4 

Bees  in  Samson's  lion  accounted  for            ....  T 

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  float  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 

Tlie  "  worm  i'  the  bud  "  traced  to  its  egg  ....  20 

Insectiferous  winds       ........  22 

Supposed  showers  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 •  ^^ 

Number  of  insect  eggs,  and  their  fecundity,  compared  with 

other  animals        .......  46 

a3 


VI 


CONTENTS. 


CHAPTER  III. 


Maternal  care  of  insects  respecting  their  eggs  . 

Instanced  in  a  carpenter-bee  (jChelustomd) 
Ichneumons  compared  to  the  cuckoo     . 
Proceedings  of  a  solitary  bee  (Halictus)      ,         , 
Stratagems  of  a  solitary  \Nasp  (Cerceris)         .  . 

Ovipositor  of  an  ichneumon  (Fiinpla)        .         , 
Experiments  of  Reaumur     .         .         .         .         . 
Common  mistakes  of  Naturalists 
Parasite  of  the  cabbage-caterpillar  {Pontia)  . 
Egg  parasites    ....         ... 

Parasites  of  the  aphides 

Singular  parasite  of  the  cockroach      .         .         . 
Rare  parasites  of  bees  and  wasps  .         .          .          . 
Tact  of  insects  in  discovering  food  for  their  young 
Sometimes  select  exotic  plants      .          .         .          . 
Instanced  in  a  leaf-miner  (TepAnti's?) 
Solitary  and  gregarious  caterpillars 
Life-boat  of  eggs  constructed  by  the  gnat     . 
Experiments  upon  it     .         .         .         •         .         . 
Infallibility  of  instinct  questioned      . 
Mistakes  of  instinct  


CHAPTER  IV. 


Hybernation  of  insects'  eggs 

Proceedings  of  the  gypsey  moth  compared  to  the  eider-duck 

Singular  groups  of  eggs     ... 

Protection  of  eggs  from  heat 

Anal  tweezers  of  moths     . 

Eggs  in  spiral  groups    .... 

Arched  form  of  the  lackey-moth's  eggs 

Hybernation  of  the  eggs  of  aphides 

Singular  protection  of  the  eggs  of  cocci 

Coccus  of  the  hawthorn 

Shell-formed  coccus  of  the  currant      . 

Hybernation  of  spiders'  eggs 

Curious  spiders'  nests 

tlggs  of  the  vapourer-moth  on  its  cocoon 

Effects  of  cold  on  insects'  eggs    . 

Observations  of  John  Hunter 

Insects  not  killed  by  severe  frosts 

CHAPTER  V. 
Hatching  of  insect  eggs        .... 
Structure  of  the  eggs  of  birds 
Insects  do  not  hatch  their  eggs  . 
Anomalous  instance  of  the  earwig. 
Earwigs  cannot  get  into  the  brain 
Partial  hatcliing  by  spiders   . 
Experiments  upon  the    wolf-spider  by   Swammerdam 

Bonnet     ..... 
Eggs  hatched  before  they  are  laid 
Ovo-viviparous  insects  . 
Coil  of  larvaj  in  the  body  of  a  hlow-flv 
Aphides  sometimes  produce  eggs,  sometimes  yonn 
Care  taken  of  these  eggs  by  ants 


and 


CONTENTS. 


Vll 


Cocco-viviparous  flies  {HippohoscidcB) 
Effects  of  heat  upon  eggs       .... 
Management  of  silk- worms'  eggs         , 
Eff"ects  of  light  on  eggs  .... 

Some  insect  eggs  increase  in  size        . 
Growth  of  the  eggs  of  ants    .... 
Development  of  the  eggs  of  spiders    . 
Spiders  live  long  without  food       .         .         , 
Insects  probably  gnaw  through  their  egg-shells 
Valves  of  insect  eggs     ..... 
Period  of  hatching  influenced  by  temperature 

SECTION  II.— LARV^. 


Page 
116 
118 
120 
ib. 
121 
122 
123 
124 
125 
126 
127 


CHAPTER  VI. 

Structure  of  caterpillars,  grubs,  and  maggots 128 

Meanings  of  these  terms  .....  Note,  ib. 

Supposed  transmutation  of  plants  into  animals      .         .         .  129 

Observations  of  Un^'er  upon  this 130 

Remarks  of  Bory  St.  Vincent 131 

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 

Diff"erence  of  plants  from  insects         .....  137 

Internal  structure  of  caterpillars 138 

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 145 

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  (iWfi.s)  may  be  mistaken  for  larvae          .         .  159 

Syringe  for  respiratiota  in  a  water  larva           ....  161 

Curious  mask  of  the  same  larva          .          .         ,         ,          .  163 

Dust  mask  of  the  wolf-bug  (BedKUfMs) 165 

CHAPTER  VII. 

Growth,  moulting,  strength,  defence,  and  hybernation  of  larvae     .  166 
Progressive  iucrease  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  lo  renal  gravel          ....  172 

Position  of  the  hairs  in  moulting 173 

Casting  of  the  interior  lining  of  the  stomach,  &c.     .         .         .  174 

Moulting  of  birds 176 

Cast  sivius  sometimes  devoured      ......  177 

Misstatement  of  Goldsmith         ......  ib. 

Contrivances  for  escape  from  confinement      ....  178 

Muscular  strength  of  insects        .....'  17^ 


CONTENTS. 


Paire 

Fleas  made  to  draw  miniature  coaches       .         .         ,         ,  180 

Numerous  muscles  of  the  C0SSU3 182 

Its  wonderful  strength 1 84 

Misstatements  respecting  the  strength  of  insects    .         .         .  185 

Means  of  escape  by  spinning     ......  1S6 

Defensive  hairs  and  spines  of  caterpillars      ....  187 

Excrementitious  covering  of  some  lar\'ae    ....  190 

Origin  of  the  froth  on  plants  called  cuckoo-spit       ...  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-worm  in  thirty  days          .         .  197 

Remarkable  change  in  the  capacity  of  the  stomach     .         .  198 

Instances  of  human  voracity          ......  201 

Jaws  or  mandibles  of  larvae 202 

Caterpillars ib. 

Blight  caused  by  an  oak-leaf  roller     .....  203 

Ravages  of  the  buff-tip 204 

Encamping  caterpillars  of  the  ermine-moth         .         .         .  205 

Experiments  with  these      i  .         .          ....         .  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  jEgeriae  on  currant  and  poplar  trees    .         .         .  220 

Destruction  of  grain  by  Kuplocami  and  Tineae       .         .         .  221 

Bee-hives  injured  by  Gallariae 222 

Caterpillar  which  feeds  on  chocolate 224 

CHAPTER  IX. 

Voracity  of  grubs "...  225 

Grub  of  the  cockchafer  or  may-biig 226 

Accountof  its  transformation,  &c '227 

Methods  of  destroying 228 

Wire-worm  the  grub  of  Hemirhipus 2l'9 

Probable  mistake  respecting  the  destruction  of  wheat     .         .  231 

Pea-beetle  of  North  America 2:^3 

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        .....  238 

Extraordi^iary  case  of  Mary  Riordan,  by  Dr.  Pickells     .         .  239 

Authenticity  of  this  case  proved          .         .         .  '      .         .  241 

Fruit-grubs           " 242 

Nut-weevil  and  its  transformations ib. 


CONTENTS. 


Apple-bud  weevil      .         .         .         . 

Voracity  of  Calosoma  . 

Rayed  galleries  of  a  bark-grub. 

Ravages  of  locusts         , 

Tlieir  swarms  in  Southern  Africa 

The  Italian  locust 

Migrations  in  Palestine  and  Europe  . 

CHAPTER  X. 


Voracity  of  maggots 

Maggots  of  crane-flies  popularly  called  the  grub 
Remarkable  ovipositor       .... 
Destruction  of  herbage  on  Blackheath  • 
Similar  devastations  in  Poitou  and  Holderness 
Wheat-fly,  described  by  Mr.  Shireff 
Additional  particulars  by  Mr.  Gorrie  , 
Observations  of  Kirby  .... 
Mistake  of  Mr.  Markwick. 
Hessian-fly,  described  by  Mr.  Say  , 

Cheese-hopper  the  maggot  of  Piophila 
Wonderful  structure  of  this  maggot 
Its  transformation  into  a  fly       .         .         . 
Origin  of  the  house-fly  (^Musca  dumestica) 
Mistakes  of  Ray  and  Reaumur  . 
Voracity  of  the  maggots  of  blow-flies     . 
Instance  of  a  man  devoured  by  them. 
Popular  mistake  respecting  lady-birds 
Their  transformations  traced  to  the  egg 
Aphides  checked  by  these  and  by  Syrphidae 

SECTION  III.— PUP^. 
CHAPTER  XI. 

MechaiMsm  of  suspending  chrysalides 

Proceedings  of  larvae  upon  their  approacKing  change 
In  what  manner  some  caterpillars  suspend  themselves 
Tlieir  attempts  sometimes  unsuccessful 
Organ  for  holding  fast        .... 
Suspensory  cincture  of  other  caterpillars 
Method  of  forming  this  by  the  swallow-tail 
Parchment-like  pupa-case  of  flies  (^Muscidce) 
Flask-shaped  pupae  of  Syrphida; 
Trausformations  of  a  Tipulidan  gnat 
Mode  by  which  the  nymph  is  suspended     . 
Hooked  aquatic  pupa  {Hydrucampa  f) 

CHAPTER  XII. 


Page 
2^3 
244 
245 
246 
247 
249 
250 


252 
ib. 
253 
254 
255 
256 
259 
260 
261 
262 
263 


267 
268 
ib. 
269 
270 
271 


273 
274 
277 
278 
279 
281 
282 


287 


Form  and  structure  of  pupae         ...... 

The  term  metamorphosis  objected  to      .         .         . 
Harvey's  fancies  about  transmutation  .         .         . 

Similar  fancies  of  Goedart  exposed  by  Swammerdam 
Structure  of  the  pupa  of  the  chameleon-fly. 
Pupa  of  the  lappit-moth        ..... 
Chrysalis  and  transformations  of  the  peacock -butterfly 
Origin  of  philosophic  errors  .... 

Changes  produced  on  pupae  by  evaporation 


ib. 

289 
290 
292 
293 
294 
296 
297 


CONTENTS. 

Page 
Objections  to  the  tlieory  of  evaporation       ....        298 

Respiratory  organs  of  pupae    ......  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  XT  1 1. 


Transformation  of  pupae  into  perfect  insects 

Theory  of  transpiration  by  means  of  heat  . 

Objections  to  this  theory 

Experiments  by  Reaumur.         .... 
Chrysalides  hatched  under  a  hen    .... 
Forcing  of  butterflies  in  winter  .... 
Retarding  tlie  evolution  of  butterflies  by  cold. 
Experiments  on  pupae  led  to  the  varnishing  of  eggs 
Illustrations  of  torpidity  in  animals  and  plants 
Various  periods  of  disclosure  in  the  same  brood. 
Supposed  final  cause  of  this    ..... 
Fixed  time  of  the  day  for  some  insects  to  be  evolved 
Remarkable  evolution  of  the  gnat   .... 
Still  more  remarkable  instance  of  the  blood-worm 
Netted  doors  in  the  pujia  cases  of  caddis-flies  . 
Bellows  apparatus  in  the  pupa  of  the  blow-fly    . 
Contrivance  in  the  pupae  of  wood  feeders         .         . 
Singularity  in  the  locust-moth 
Ingenious  contrivance  in  a  small  leaf-roller 
Mistake  of  Bonnet  with  respect  to  the  teazle-moth 
Pupa  cases  opened  by  extraneous  assistance    . 
Observations  on  this  by  the  younger  Huber 
Experiment  by  Dr.  J.  R.  Johnson  .... 
De  Geer's  observations  contrary  to  those  of  Swammerdam 
Remarkable  circumstance  in  the  hive  bee 


307 
ib. 


310 
311 
312 
ib. 
313 
314 
315 
316 
317 
319 
320 
321 
322 
323 
324 
325 
326 
327 
329 
330 
331 


SECTION  IV.     PERFECT  INSECTS. 


CHAPTER  XIV. 


Expansion  of  the  body  and  wings  in  insects  newly  transformed 
Structure  of  birds  to  contain  air      .... 


333 
ib. 

Expansion  in  the  fly  of  the  ant-lion  .         .         '         .         .         'Si4 
The  mandibles  prove  it  carnivorous         ....  335 

Transformations  of  dragon -flies 336 

Folded  wings  of  some  two-wiuged  flies     ....  338  [ 

Mali>ighi's  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  butterfly342 
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 


CONTENTS. 


XI 


Theories  devised  to  account  for  crimson  snow     . 
Curious  fact  explaining  this,  by  Mr.  T.  Nicholson 
Does  not  explain  the  red  snow  of  the  Alps. 

CHAPTER  XV. 


Peculiar  motions  of  insects 

Motion  indispensable  to  life    .... 

Anecdote  of  a  water-measurer     . 

Mode  of  combing  themselves  used  by  spiders  . 

Oscillatory  motions  of  some  tipulidae. 

Vibratory  motions  of  syr][ihi  on  the  wing. 

Similar  motions  of  hawks,  red-breast,  &c.  . 

Experiment  on  Scioptera  vihrans      .         .         . 

Ilhistrated  by  the  wag-tail,  &c.. 

Gnat  dauces  in  winter    ..... 

Opinion  of  Wordsworth  and  others 

Similar  aerial  dances  of  rooks 

Night  gambols  of  Corethrce?  on  a  book 

Circular  movements  of  a  summer  fly        .         . 

Sportive  movements  not  necessarily  social . 

Account  of  the  whirlwig,  by  Kirby  and  by  Knapp 

Remarkable  structure  of  its  eyes 

Battles  of  butterflies        .... 

Choral  assemblies  of  ephemeridae      .         • 

Account  of  these  by  Reaumur 

Sports  of  ants    ...,., 

Gymnastics  of  ants,  according  to  Huber  . 


Page 
352 
354 
355 


356 
ib. 
357 

358 
359 
360 
361 
362 
363 

ib. 
364 

ib. 
365 
366 
367 
368 
370 
371 
373 

ib. 
376 
377 


CHAPTER  XVI. 

Peculiar  locomotions  of  insects     .......  379 

Examples  from  quadrupeds    ......  ib. 

Singular  movements  of  some  plant-bugs      ....  380 

trailing  of  the  whirlwig  beetle.         .....  381 

Walking  on  water  by  spiders,  &c 382 

Walking  through  water  by  aquatic  mites         •         .         .  383 

Oblique  pace  of  midges      .......  384 

Insect  with  its  legs  on  its  back         .....  385 

Rapid  galloping  of  the  strawberry-mite       ....  386 

Slow  movements  of  the  oil-beetles 387 

Supposed  sponges  in  the  foot  of  the  fly        .         .         .         .  388 

Correct  notions  of  Derham  and  White,  proved  by  Sir  E.  Home  389 

Apparatus  in  the  feet  of  flies 390 

Leaping  muscles  of  the  flea     ......  392 

Leaping  of  grasshoppers  and  springtails      ....  393 

Springing  of  spiders  on  their  prey 394 

Flight  of  insects .395 

Mechanism  of  insects'  wings  and  their  muscles,  according  to 

M.  Chabrier 396 

Flying  of  spiders  without  wings 397 

CHAPTER  XVn. 

Rest  of  insects 399 

Night  insects  rest  in  the  day ib. 


xu 


CONTENTS. 


Day  movements  of  other  insects      .         .         .         .         . 
Insects  have  no  brain,  nor  spinal  cord 
Want  also  a  proper  heaii;  as  well  as  blood 

Supposed  pulse  in  insects 

No  circulation 

Alleged  discovery  of  an  insect  circulation,  by  Dr.  Cams 
How  the  circulation  is  effected  in  the  sleep  of  man  . 
The  same  effects  cannot  take  place  in  insects 
Sleep  of  senses  not  equally  profound       .         .         .         . 

Torpidity  of  insects  in  winter 

Hybernation  of  ants       ....... 

Anecdotes  from  Huber       ...... 

Hybernation  of  bees 

Discrepancies  of  opinion  among  naturalists 
Hybernation  of  the  hearth-cricket 


Page 
•100 

ib. 
401 

ib. 
402 

ib. 
404 
405 
406 

ib. 
407 
408 
410 
413 
414 


INSECT  TRANSFORMATIONS. 


SECTION  I.— EGGS  OF  INSECTS 


Chapter  I. 

All  Insects  come  from  Eggs  as  Plants  do  fr.om  Seeds. — Vnlt;ar  errors 
of  Insects  being  generated  by  Putrefaction  and  Blighting  Winds  dis 
proved  by  experiment. 

It  was  universally  believed  by  the  ancient  philoso- 
pliers,  that  maj^gots,  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  devouring, 
or  a  flock  of  sheep  from  the  grass-field  in  which  they 
graze.  Another  opinion,  perhaps  still  more  generally 
diffused,  is,  that  caterpillars,  aphides,  and  other  garden 
insects  which  destroy  the  leaves  of  plants,  are  gene- 
rated, propagated,  or,  at  least,  spread  about,  by  certain 
winds  or  states  of  the  air,  mysteriously  and  inde- 
finitely termed  blight.  The  latter  belief  is,  probably, 
not  so  easy  of  immediate  refutation  as  the  former; — 
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  oif  fanciful  opinions  regarding  them,  since  it 
is  diflkult  for  common  observers  to  detect  mistakes ; 

B 


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  : — 

"  Take  some  snakes,"  says  he,  '*  of  whatever  kind 
3»ou  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  tliat  the  piece  of 
ground  be  exposed  to  the  spring  sun,  and  in  eight 
days  you  will  see  the  earth  strewn  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,  "  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  handf." 
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. 
f  Redi,  Generat.  Xnsectorum,  ed>t.  Axnstel,  1686. 


GENERATION   OF    INSECTS.  3 

tioiiably,  that  the  imagination  of  Kircher  had  mag- 
nified 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,  unfinished, 
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,  however,  they  "un- 
folded their  wings  and  changed  into  a  vivid  green, 
marveKously  brilliant" — most  probably  the  green 
flesh-fly  (Mil sea  CfBsar.  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 
afterwards  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  aquaticus,  Linn.),  and  between  this  and 
a  young  eel.  This  fabled  transformation  of  hair, 
which  we  have  heard  maintained  even  by  several 
persons  of  good  education,  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  "  Episode  of  Aristseus  recovering  his 
bees"  has  been  pronounced  to  be  "  perhaps  the 
finest  piece  of  poetry  in  the  world,"  we  must  be  per- 
mitted to  say  that  it  is  quite  fabulous  and  unphiloso- 
phical*     The  passage  runs  thus  : — 

Oft  from  putrid  gore  of  cattle  slain 
Bees  have  been  bred.  *  *  *  ^  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, 
His  horns  just  bending  in  their  second  year  ; 

b2 


4  INSECT    TRANSFORMATIONS. 

Him,  much  reluctant,  with  o'evpow'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  batter'd  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  onliigh. 
Meanwhile  the  juices  in  the  tender  bones 
Heated  ferment ;   and,  wondrous  to  heholdy 
Small  aniniiils,  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  fig-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 
wing?,  and  short  antenna?,  while  all  bees  have  four 
wings,  and  long  antennae.     Neither  the  flies  nor  the 


Comparative  figures  of  a  bee  (a)  and  a  syrphus  (6). 

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  founil 
ill  the  carcasses  of  animals  in  summer,  "some- 
what resemble  those  produced  by  the  egc^s  of 
bees.  However  ridiculous,''  lie  adds,  "  the  opinion 
must  appear,  many  great  men  have  not  been 
ashamed  to  adopt  and  defend  it.  The  industrious 
Goedart  has  ventured  to  ascribe  tlie  origin  of 
bees  to  certain  dunghill  worms  *,  and  the  learned 
De  Mei  joins  with  him  in  this  opinion  ;  though 
neither  of  them  had  any  observation  to  ground  their 
belief  upon,  but  that  of  the  external  resemblance 
between  bees  and  certain  kinds  of  flies  {Syrphidce) 
produced  from  those  worms.  The  mistake  of  such 
authors  should  teach  us,"  he  continues,  "  to  use 
great  caution  in  our  determinations  concerning 
things  which  we  have  not  thoroughly  examined,  or 
at  least  to  describe  them  with  all  the  circumstances 
observable  in  them.  Therefore,  although  this  opi- 
nion of  bees  issuing  from  the  carcasses  of  some  othet 
animals  by  the  power  of  putrefaction,  or  by  a  trans- 
position 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  requi- 
sites 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  himself  out  of  that  laby- 
rinth of  idle  fancies  and  unsupported  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  results 
of  his  experiments  upon  the  flesh  of  snakes,  for  several 

*  The  maggots  of  Eristalis  tenax,  Famsi.  E.  api/ormis, 
Mkiokn,  and  other  Syrphidcr,  well  known  in  common  sewers  by 
their  long  tails,  like  those  of  rats. 

f  Swammerd.  Book  of  Nature,  i.  228. 

11  3 


6  INSECT    TRANSFORMATIONS, 

species  of  flies  were  produced,  giviiin;  some  coun- 
tenance to  the  opinion  of  Aristotle,  Pliny,  Mouffet, 
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  oi  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  oi  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  anything  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  t,  and  other  small  animals  which  they  cannot 
remove  J. 

These  facts,  which  are  unquestionable,  may  at 
first  view  appear  to  contradict  the  Scripture  history 

*  Aristotle,  Hist.  Animal,  ix.  40.    Pliny  says, "  Omnes  carue 
cscuiitur,  contra  quam  apes,  quae  nullum  corpus  attinguut." 
f   Iluish  on  Bees,  p.  100. 
I  Insect  Architecture,  p.  109, 


GENERATION    OF    INSECTS.  7 

of  Samson,  who,  havinp;  killed  a  young  lion  in  the 
vineyards  ofTimnath,  "after  a  time  turned  aside  to 
see  the  carcass  of  the  Hon  :  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  still  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,  "  not 
only  do  not  Hve  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  Spence  seem  disposed  to  consider  Samson's 
bees,  as  we  have  done  those  of  Virgil,  to  be  flies 
resembUng  bees;  but  the  "  honey  "  which  Sauison 
"  took  in  his  hands  and  went  on  eating,"  is  fatal  to 
such  an  exposition. 

The   ancients    had   another   fancy   respecting  the 
*  Judges  xiv.  8. 


B  INSECT   TRANSFORMATIONS. 

propaga  on  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  t,  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  |.".  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  Q^'g)  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  "  Earth-born "  (Erich- 
ihojiii),  and  wore  golden  tree-hoppers  (^Cicadce)  in 
their  hair,  erroneously  supposing  these  insects  to 
have  a  common  origin  with  themselves  §.     Lucretius 

*  Hist.  Animal,  v.  22. 

f  Le  Portrait  de  la  Mouche  a  Miel.  Liege,  1646. 

X  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  Cicada;  do  not  deposit  their  eggs  in  the  earth,  but  on 
lices,  &c.     See  Insict  Arcbitcctitre,  cliap.  vii. 


GENERATION    OF    INSECTS.  9 

affirms,  that  even  in  his  time,  when  the  earth  was 
supposed  to  be  growing  too  old  to  be  reproductive, 
"  many  animals  were  concreted  out  ot"  mud  by 
showers  and  sunshine*." 

But  the  ancients,  it  would  appear,  had  the 
shrewdness  seldom  to  venture  upon  illustrations  of 
their  philosophical  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  cerebri- 
formh,  ParkinsonI).  Darwin,  again,  taking  the 
hint  from  Epicurus,  dreams  that  animals  arose  from 
a  single  filament  or  threadlet  of  matter,  which,  by 
its  efforts  to  procure  nourishment,  lengthened  out 
parts  of  its  body  into  arms  and  other  members. 
For  example,  after  this  filament  had  improved  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  into  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  ditlerent  forms  of  the  bills  of  birds,  whether 
hooked,  broad,  or  long,  were,  he  says,  gradually 
acquired  by  the  perpetual  endeavours  of  the  creatures 
to    supply    their   wants.      The   long-legged    water- 

*  Multaque  nunc  etiam  existunt  animaVia  terris, 
Imbribus  et  calido  soils  concreta  vapore. 

De  Nat.  Rer.  v.  795. 

f  Robinet,  Consid.  Philosophiques  dc  la  Gradation  Naturelle 
des  Formes  de  TEtre.    Paris,  1768. 


lO  INSECT  TRANSFORMATIONS. 

fowl  {Grallatores^  Vigors)  in  this  way  acquired 
length  of  legs  sufficient  to  elevate  their  bodies  above 
the  water  in  which  they  waded.  "  A  proboscis,"  he 
says,  "  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*." 
Lamarck,  an  eminent  French  naturalist,  recently  de- 
ceased, adopted  the  same  visions  ;  and,  among  other 
illustrations  of  a  similar  cast,  he  tells  us  that  the 
giraffe  acquired  its  long  neck  by  its  effects  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  (iirther  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  exjieriments  of  Redi  on  the  hatching  of  insects 
from  eggs,  which  were  published  at  Florence  in 
1668,  first  brought  discredit  upon  this  doctrine, 
though  it  had  always  a  few  eminent  disc  pies.  At 
present  it  is  maintained  by  a  considerable  number 
of  distinguished  naturalists,  such  as  Blumenbach, 
Cuvier,  Hory  de  St.  Vincent,  R.  Brown,  &c.  "The 
notion  of  spontaneous  generation,"  says  Bory,  "  is 
al  first  revolting  to  a  rational  mind,  but  it  is,  not- 
withstanding, demonstrable  by  the  microscope.  The 
fact  is  averred:  Midler  has  seen  it,  I  have  seen  it, 
and  twenty  other  observers  have  seen  it :  the  pan- 
durinia  exhibit  it  every  instant  t-"     These  pandorinia 

♦  Darwin'  Zoonomia,  sect,  xxxix.  3id  edit.     London,  1801. 
f  Diet.  Classi(iue  d'  Hist.  Nat.,  Art.  Microscopiques,  p.  541. 


GENERATION   OF    INSECTS.  II 

he  elsewhere  describes  as  probably  nothini?  more 
than  "animated  scions  of  Zoocarpse "  (propagules 
animes  des  Zoocarpes).*  It  would  be  unprofitable 
to  g:o  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 
influenced  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 
bfyond  a  doubt  to  originate  in  the  play  of  chemical 
affinities  or  galvanic  actions — (a  more  refined  pro- 
cess, 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  animalcules  and  zoophytes,  there- 
fore, out  of  the  question,  we  have  only  to  examine 
such  branches  of  the  theory  of  spontaneous  genera- 
tion as  seem  to  involve  the  propagation  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  blijikan,  to  strike  with  lightning), 
is  almost  universally  believed  even  by  the  most 
intelligent,  if  they  have  not  particularly  studied  the 
habits  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  wafted  through  tlie 
*  Diet.  Class,  Art.  Pandoriuoes. 


12  INSECT    TRANSFORMATIONS. 

air  by  this  same  mist*."  *'  The  farmer,"  says 
Keith,  *'  supposes  these  insects  are  wafted  to  him 
oil  the  east  wind,  while  they  are  only  generated  in 
the  extravasated  juices  as  forming  a  proper  nidus  for 
their  eggst."  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  excellent  general  naturalist,  his  testimony 
merits  every  attention  • — 

"  That  the  atmosphere,"  says  Dr.  Good,  "  is 
freighted  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  wonderful  effects  of  what,  in  common  lan- 
guage, is  called  a  blight  upon  plantations  and  gar- 
dens. I  have  seen,  as  probably  many  who  read  this 
work  have  also,  a  hop-ground  completely  overrun 
and  desolated  by  the  aphis  hmmili,  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  exhaustion, 
renders  them  a  favourite  resort  tor  this  insect,  and  a 
cherishing  nidus  for  myriads  of  little  dots  that  are  its 
eggs.  The  latter  are  hatched  within  eight-and-forty 
hours  afier  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  ;  tor,  in  ditferent 
seasons  of  the  year,  the  aphis  breeds  both  ways. 
Now   it    is   highly   probable   that  there   are   minute 

*  Loudon's  Ma  jr.  of  Nat.  Hist.  i.  180. 
+  Keith's  Physiological  Botany,  ji.  486. 


GENERATION   OF    INS-ECTS.  13 

efygs,  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  eggs  of  any  species  of  animalcules  or 
insects  float  about  in  the  atmosphere;  for,  inde- 
pendent of  their  weight,  (every  known  sjiecies  being 
greatly  heavier  than  air,)  the  parent  insects  of  every 
species  whose  history  has  been  accurately  investi- 
gated, manifest  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  admitting  for  a  moment  this  hypothesis,  that  the 
eggs  of  insects  are  diffused  through  the  atmosphere, 
the  circumstance  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 

;  i  float    about,   unhatched,  from   the    end    of  summer 

I  I  till  the  commencement  of  spring,  at  which  time  only 

,,  i  the  broods  make  t.ljeir  appearance.     Yet  when  we 

"        *  Good's  Study  of  Medicine-  vol,  i ,  p.  339,  Srd  edition,  Lon- 
don, 18^3. 

C 


14  INSECT   TRANSFORMATIONS. 

-Consider  the  rains,  snows,  and  winds,  to  which  they 
must  be  exposed  for  six  or  nine  months,  we  think 
the  hardiest  theorist  would  scarcely  maintain  that  a 
single  egg  could  out-weather  these  vicissitudes,  and 
continue  to  float  in  the  air.  It  may  not  be  out  of 
place  to  remark,  that  the  female  aphides,  which  de- 
posit 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*, 
enveloi)ed  in  an  adhesive  cement  wliich  glues  them 
to  the  spot  on  which  they  are  deposited.  When 
eggs  are  deposited  singly,  this  cement  usually  enve- 
lopes each  with  a  thin  coating,  as  in  the  instance  of 
the  admirable  butterfly  {Vanessa  Atalanta)  ;  but 
when  they  are  placed  in  a  group  the  cement  is 
sometimes  spread  over  the  whole,  as  in  the  instance 
of  the  white  sain  moth  (^Leucoma  salicis,  Ste- 
phens). 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  selected  by  the  mother  insect  for  their 
deposition.  Those  eggs,  therefore,  which  are  placed 
on  the  outside  of  substances,  have  this  provision 
for  their  secure  attachment  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  excavations,  and  particularly  as 
to  those  of  ants  and  termites.  The  working  ants,  in- ' 
deed,  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  (^Tennites) ^  again,  attend  their  queen  with 
the  utmost  care  when  she  is  laying  ;  for  as  she  can- 
not then  move  about,  they  are  under  the  necessity 
*  Latreille,  Hist.  Grener.  xiv.,  p.  342. 


GENERATION   OF    INSECTS.  15 

of  carryino:  off  the  eg-g-s,  as  they  are  laid,  to  the 
nurseries.  The  extraordinary  labour  which  this  re- 
quires ill  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  men- 
tioned, however,  do  not  in  the  least  invalidate  on*" 
general  position. 


Cell  of  a  queen  of  the  Termites  bclhcosi,  uroKcn  open  in  front , 
the  labourers  surrounding  thu  queen  and  carrying  off  her  eggs. 

Another  no  less  remarkable  circumstance  is  the 
great  weight,  or  specific  gravity,  of  the  egg-s  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 
{Odonestis  Potatoria^  Germar),  which  is  nearly  as 
large  as  a  hemp-seed,  to  that  of  the  rose-plant  louse 
{Aphis  ros(E),  which  is  so  small  as  to  be  barely  visible 
to  the  naked  eye.  Some  eggs  of  the  gipsy  moth 
{Ilypogyrnna  dispar,  Stephens),  indeed,  floated  in 
water,  because  they  were  covered  vvith  down.  It  is 
well  known,  as  we  shall  presently  show,  that  the  dif- 
fusion of  many  of  the  seeds  of  plants  is  accomplished 
by  the  winged  down  with  which  they  are  clothed  ; 

c2 


16  INSECT   TUANSFORMATIONS. 

but  the  down  upon  the  et^gs  of  insects  does  not 
conduce  to  this  end.  Whether  insect  egi^s  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  specific  gravity  of  eggs,  it  should  be  remembered 
that  no  infertile  or  unimpregnated  egg  will  sink; 
for  having  some  hundreds  of  these  laid  by  dif- 
ferent 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  {Lozoticnia  Rosana,  Stephens) 
was  reared  by  us,  in  solitude,  under  an  inverted 
wine-glass,  uj)on  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  gipsy  moth,  and 
numerous  other  insects*. 

Dr.  Good's  account  of  "  honey  dew,"  which  he 
describes  as  "  a  peculiar  haze  or  mist  loaded  with  a 
poisonous  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 t,  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  hiimuU)  attacking  the 
roots.  Dr.  Withering,  favouring  this  account,  re- 
commends covering  the  roots  with  stones  as  a  preveu- 

*  J.  R.  t  Quoted  by  Keith,  Phys,  Bot.,  ii.  143. 


GENERATION   OF    INSECTS.  17 

live;  for  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  coat- 
ing-, called  honey-dew,  found  on  the  leaves  of  the 
hop,  is  nothing  more  than  the  excrement  of  the  insect 
{Aphis  hunudi)  whose  propagation  we  are  discussing. 
•'  The  honey-dew,"  says  Loudon  "  mostly"  (we  be- 
believe  always)  "  occurs  after  the  crops  have  been 
attacked  by  these  insects."  f  Sir  J.  E.  Smith,  who 
admits  this  to  be  the  connnon  cause  of  honey-dew, 
contends  tliat  what  is  found  on  the  leaves  of  the  beech 
is  an  exception;  but  he  adduces  no  evidence  at  all 
satisfactory  in  proof  of  its  being  caused  by  unfavour- 
able winds  J  ;  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  vteather  had  been  parched  and  sultry 
ior  some  weeks  previous,  and  the  honey-dew  pre- 
vailed to  such  an  extent,  that  the  leaves  of  the  cur- 
rant, raspberry,  &c.,  in  the  gardens,  literally  distilled 
from  their  tips  a  clear  limpid  honey-dew,  excreted 
from  the  plant;  lor  the  phenomenon  was  observable 
on  those  plants  that  were  entirely  free  from  aphides, 
and  so  copious  vvas  it,  where  these  insects  were 
found,  that  had  their  numbers  been  centuple  they 
could  not  certainly  have  been  the  source  of  the  sup- 
ply. The  question  with  me,  however,  was  set  at  rest 
by  applying  a  lens,   having  previously  washed  and 

*  Botan,  Arrangement,  ii.,  440,  3r(l  ed, 
Encycl.  of  Agnculturo,  p.  865,  s.  5444. 
X   Intioductiun  to  Botany,  p.  189. 
(  Sec  Liuii.  Traua.  vol.  vi.  &  WiUdtuow,  Piuicip.  of  Botany .p.34o\ 

c  3 


18  INSECT   TRANSFORMATIONS. 

dried  the  leaf  by  a  sponge,  for  in  this  case  the  imme* 
diately  excreted  globules  became  apparent*." 

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  irreconcileable  with  Mr.  Murray's 
ingenious  theory.  The  hop  fly  {Aphis  humuli)  we 
think,  neither  does,  nor  (for  want  of  appropriate  or- 
gans) can,  feed  on  the  honey-dew  ;  and  if  it  did,  this 
feeding  would  prove  rather  beneficial  than  otherwise 
to  the  plant,  by  clearing  it  from  the  leaves  whose  re- 
spiratory 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  {hausteUum) ,  which  in 
some  species  is  much  longer  than  the  body,  and  no 
more  fitted  for  lapping  honey-dew  than  the  bill  of 
iEsop's  crane  was  for  eating  out  of  a  shallow  plate. 
In  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,  t.  We  have  now  in  our  study  a  plant  of 
the  Cliinese  chrysanthemu  m  {Anthcmis  Artemisi<B 
*  Treatise  on  Atmospherical  Electricity,  j).  117,  Loud,  1830, 
{■  Trans.  Soc.  Roy.  de  MontpelUei. 


GENERATION    OP   INSECTS.  i9 

^olia,  WiLLD,),  the  young  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  ac- 
tually seen  the  aphides  ejecting  the  honey-dew*. 

The  almost  instantaneous  appearance  of  these 
destructive  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  considerable  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,  having  all  been  laid  at  the  same  time,  and  ex- 
posed to  the  same  degrees  of  temperature,  are  of 
course  all  simultaneously  hatched.  In  the  case  of 
the  aphides,  also,  the  fecundity  is  almost  incalculable. 
Reaumur  proved  by  experiment,  that  one  aphis  may 
be  the  progenitor  of  5,904,900,000  descendants  dur- 
ing 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  may  be  twenty  generations.  We 
ourselves  have  counted  more  than  a  thousand 
aphides  on  a  single  leaf  of  the  hop;  and  in  sea- 
sons 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  preservation 
and  hatching  of  these  eggs  in  the  ensuing  spring 
must,  it  is  obvious,  depend  on  the  weather  and  other 
*  J.  R. 


20 


INSECT   TRANSFORMATIONS. 


accidenta    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  caterpillar, 
for  example,  of  Lozotcenia  Rosalia^  mentioned  be- 
fore, 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 


r.'^Ax. 


Two  groups  of  eggs  of  the  Ro;.e-lcaf  roller  {Lozotccjiia  R/jsam') 
on  a  pane  of  glass. 

*  J.  R. 


GENERATION    OF    INSECTS.  21 

oi"  the  same  colour,  sometimes  upon  the  branches  of 
the  rose-tree,  but  more  frequently,  as  we  have  ob- 
served, upon  some  smooth  object  contig-uous.  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 
hatched,  two  or  three  hundred  caterpillars  would  at 
once  be  let  loose,  and,  streaming  down  simultane- 
ously upon  the  rose-tree  beneath,  would  soon  devoar 
the  greater  number  of  its  buds.  As  this  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  extraor- 
dinary number  of  similar  groups  of  the  eggs  of  a 
leaf-roller  {Lozotceiiia  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  1829-30,  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  undevourcd.  For  this  spring,  at  least,  these 
currant  bushes  will  be  safe  from  their  attacks,  and  or 


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,  wheii 
hatched,  are  scarcely  so  thick  as  a  thread  of  sewing 
silk,  and  being  of  a  greenish  colour,  they  are  not 
readily  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  suj)position  ;  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  rarely  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  from  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 
Ihem,  They  were  all  proceeding  in  the  same  direc- 
tion towards  some  woods  and  ditches  ;  and  lie  traced 
*  J.R. 


GENERATION    OF    INSECTS.  23 

them  back  to  the  side  of  a  very  ]i\rg;e  pond,  which, 
in  spawning  time,  he  was  informed,  swarmed  with 
countless  numbers  of  frogs,  lie  naturally  concluded, 
therefore,  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 
refreshing  shower,  to  go  in  quest  of  food  *.  Their 
g-reat  numbers  will  appear  less  marvellous,  when  we 
consider  that  a  single  frog  spawns,  as  De  Mont- 
beillard  informs  us,  about  1300  eggsf.  Were  it  not, 
indeed,  for  their  numerous  enemies,  and  their  not 
being  tit  to  propagate  till  they  are  three  years  old, 
the  country  would  soon  be  overrim  with  these 
reptiles.  We  have  more  than  once  seen  a  similar 
legion  of  hair-worms  {Gordii  aquaiici,  Linn.)  in  a 
garden  at  Lee,  in  Kent,  every  plant  and  spot  of 
ground  literally  swarming  with  them.  Their  num- 
bers, however,  were  easily  accounted  for,  as  a  stream 
at  the  bottom  of  the  garden  abounds  with  them,  and, 
like  frogs,  they  appear  to  be  amphibious  |. 

The  errors  of  theory,  as  well  as  the  mistakes  ot 
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. 
■{■  Diet.  Classique  d'Hist.  Nat.,  vii,,  p.  495.  %  J.  R. 

§  Horae  Kntomologicae,  or  Essays  on  Annulose  Animals,  8vo, 
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  ghie  at  the  moment  of  exclusion, 
while  the  seeds  of  plants  are  no  less  uniformly  ditfu- 
sable  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  ditfusion  of  the  seeds  of  thistles^ 
groundsel,  dandelion,  &c.,  by  means  of  feathery 
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  »oculament, 
consisting,  however,  of  three  valves.  To  the  inner 
part  of  each  of  these  valves  a  seed  is  attached,  and 
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  vioiacese,  worthy  of  remark. 
Before  the  seed  is  ripe,  the  capsule  hangs  in  a  droop- 
ing position,  with  the  persisting  calyx  spread  (jver  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  ripenin£T'  completed,  than  tlie  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  illus- 
tration of  the  power  in  plants  of  discharging  their 
seeds,  the  remarkable  instance  of  a  minute  fungus 
{Sphceroholus  stellatus^  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  bigger  than  a  pin's  headt. 

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  hmjiuli), 
for  example,  ejects  its  minute  black  eggs  vvith  so 
much  rapidity,  that  De  Geer  describes  them  as 
miming  from  the  oviduct  ;  and  they  are  sometimes 
forcibly  thrown  out  like  pellets  from  a  pop-gun  J. 
"  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  Ma^.  of  Nat.  Hist.,  i.  380. 

■f-  For  a  minute  account  of  this  singular  plant,  see  Gieville's 
Scottish  Cryptogamic  Flora,  No.  xxxii. 

X  De  Geer,  Mem.  des  Insectes,  iv.  49  I. 

^  Kirby  and  Speiice,  Intr.  lii.  G6. 

D 


26 


INSECT   TRANSFORMATIONS. 


tioned  by  the  Abbe  Preaiix,  of  a  four-winp^fHl  fly, 
called  by  him  Mouche  baliste,  which,  when  caug-ht, 
jets  out  its  eggs  at  intervals,  as  if  by  the  jerk  of  a 
spring*. 

Tlie  apparent  analogy,  however,  between  these  in- 


A,  Plants  of  Splicer oholus,  natural  size.  B,  magnified  view.  C,  sec- 
tional view,  with  the  seed  just  previous  to  projection.  D,  the  seed  in 
the  act  of  projection.  E,  a  plant  immediately  after  projection;  a,  the 
seed;  h  h,  a  line  indicating  its  course. 

*  Diet.  Classique  rVHist.  Nat.,  Art.  Mouchf.s  B.^mstks. 
The  words  are  "  Insecte  a  quatre  ailes,  qui  lance  ses  ceufs  a 
diversos  reprises,  et  commc  par  un  lessort,  lorsqu'on  le  satsit.^' 


DISPERSION    OF    SEEDS.  27 

sects  and  the  plants  which  discharc;e  their  seeds, 
will  disappear,  when  we  consider  that  the  scattering 
of  the  seeds  is,  in  the  plants,  a  reg-ular  and  constant 
process  of  natnre  ;  whereas,  the  insects  only  jet  out 
their  eg'gs  from  fear  ichen  caught.  The  power  of 
throwing  their  eggs  to  a  distance,  indeed,  could  be 
of  no  possible  use  to  insects,  because  they  possess 
the  more  efficient  power  of  locomotion. 

The  facts  which  we  have  thus   stated  with  regard 

i  to  the  seeds  of  plants  being  diffused  by  the  means 
of  winged  down,  or  by  the  more  remarkable  capacity 

ji  of  being  projected,  differ,  as  we  have  shown,  itq  some 
important  circumstances  from  the  nearly  similar 
arrangement  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  (^Cryptogamiee^  Linn.,  Acotyledones^  Juss., 
Cellulares,  De  Candolle)  being  so  universal,  and 
the  seeds  {sjjorules)  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  watcliing  the  progress  of  this  green 
matter,  which  had  been  untiuccessfully  investi^'ated 

D  2 


tH  INSECT    TRANSFORMATIONS. 

by  Priestley,  Iiii^euhouz,  and  Ellis,  and  had  been 
mistaken  by  Linnicus  for  a  crop  of />?/s\s/,  ascertained 
beyond  quesiion  that  it  always  consisted  of  the 
minute  buds  of  common  mosses,  such  as  the  wall 
screw  moss  {Tortula  muralis)  and  the  common  hair- 
hood  moss  (^Polytrichmn  commune)*.  At  Glasgow, 
xve  have  repeatedly  remarked,  that  o!i  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  in- 
numerable germinating'  mosses +. 

The  germination  of  mosses  on  walls  appears  to 
arise  from  the  seeds  {sporides)  being  carried  into  the 
air.  This  process  is  iacilitated  by  their  extreme  mi- 
nuteness 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 
frequently  as  on  walls.  In  low  situations,  the  mode 
in  which  the  seeds  of  cryptogamic  plants  are  ditfused 
is  well  exemjjlitied  in  tlie  puif-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  omly  state  this  as  a  highly  probable  inference 
from  Drunimond'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  iniwimerable 

*  Liiiii.  Trans.  f  J.  K 


DISPERSION    OF    SEEDS.  29 

mosses  are  wafted  to  the  walls  tlirouoh  tlie  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  tlie 
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  {Hisymhrium  officinale)  and  chick- 
weed  {Aldne  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 
Telescope  for  1823,  that  the  coltsfoot  (Tussilago 
farfard)  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  cryptogamic  plants, 
and  consequently  more  difficult  to  trace,  is  well  known 
by  the  popular  name  of  mould  or  mouldiness  (Mu~ 
cedines,  Linn.)  This,  Adolpe  Brongniart  justly 
remarks,  is,  in  one  of  its  groups,  nearly  allied  to  the 
putf-balls  (JLycoperda),  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,  suppot^ed  to  be  the  seed. 
MicheU,  of  Florence,  an   eminent  botanist,  resolved 

■^3 


30 


INSECT   TRANSFORMATIONS. 


to  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  had 
been  sown ;  but  Spallanzani,  by  more  accurate  at- 
tention, confirmed  the  conclusion  of  Micheli.  He 
collected  a  great  quantity  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. 


Blicroscopic  views  of  apple  and  pear  mould.  A  A,  Part  of  a 
shrivelled  apple,  covered  with  mould  on  the  inside,  aaaat 
several  of  tlie  individual  mould  plants  highly  magnified,  b,  a 
branched  one.  c  d,  seed-vessels,  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  ditferent  species,  resembling  the 
green  mould  on  the  rind  of  oranges  (Acrosporiu?n 
fasciculatmn,  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  intro- 
duced while  it  was  in  embryo,  in  some  such  way  as 
the  seeds  of  the  subcortical  fungi  so  abun«]ant  on 
dead  leaves  and  branches  of  trees.  Th^s  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,  Cumberland,  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  visiting  Cape  Verd, 
was  struck  with  the  venerabie  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,  marvellous  to 
say,  he  actually  found  it  under  300  layers  of  wood  t ! 
De  CandoUe,  one  of  the  greatest  living  botanists, 
remarked  "  a  frost-bitten  part  in  the  wood  of  a  tree, 
cut  down  in  l^OO    hi  the  forest  Of  'Fontainebleau. 

*  Phi'l.  Trans.,  vol.  xli.  p.  448. 
t  Adansou,  Voyages     Senegal. 


32  INSECT   TRANSFORMATIONS. 

This  heino-  covered  with  ninety-one  layers  of  wood, 
indicated  that  the  accident  occjirred  in  1709,  so  re- 
markable for  a  severe  frost*.'*  With  these  facts 
before  us,  we  think  the  introduction  of  the  seed  of 
the  mould  into  the  centre  of  the  apple  by  no  means 
so  unaccountable  as  at  first  view  it  appeared.  Be 
this  as  it  may,  we  tried,  with  the  seed  g-athered  from 
this  apple-mould,  similar  experiments  to  those  of 
Spallanzani,  with  results  precisely  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  moidd  arises  from  seed,  other- 
wise nature  must  produce  the  same  effect  from  dis- 
similar causes,  which  is  contrary  to  the  first  principles 
»»f  sound  philosophy  t- 

*  Coiiv.  on  Veg.  Physiol,  i.  59.  f  J.  R» 


Chapter  II. 

Physiology  of  Insects'  Eggs.— Their  Colour,  Structure,  Shape,  Site, 
and  Number. 

It  was  a  notion  of  Darwin's  (much  more  ingenious 
and  plan  ible  than  his  metamorphoses  of  shell-fish 
into  birds,)  that  the  variety  in  the  colours  of  ei>:<;s, 
as  well  as  the  colours  of  many  animals,  is  adapted  to 
the  purposes  of  concealment  from  their  natural  ene- 
mies. 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  liollows 
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  at- 
tractive. Amongst  birds  w.hose  eggs  are  perfectly 
white — the  most  conspicuous  of  all  colours, —  he 
instances  the  kingfisher  (Jlccdo),  which  builds  in 
a  hole  in  a  river's  bank;  the  woodpecker  (P/c?/.s), 
which  builds  in  the  hole  of  a  tree;  and  the  swallow 
{Hirundo  domesiica),   whose  nest  has  a  very  small 

*  Zoonomia,  Sect.  39,  p.  248,  Srd  ed.,  and  Botan.  Gardt'n, 
note  on  Rubia. 

f  Verhuiid.  der  Gesel'lsch.  Natiufurhch.  Freunde.  Berlin, 
1824. 


3t  INSECT   TRANSFORMATIONS. 

opening:  while  owls  and  hawks,  which  scarcely  quit 
Iheir  nests  in  the  day,  and  pig-eons,  which  only  lay 
one  or  two  eg-g-s  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  {Stiirnus  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  alleges,  lay  eggs  of  a  dull  or  dark  ground, 
and  variously  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  destruc- 
tion. We  may  add  from  Darwin  the  examples 
of  the  hedge-sparrow  {Accentor  modiilaris)^  whose 
eggs  are  greenish-blue,  as  are  those  of  magpies 
and  crows,  which  are  seen  from  beneath  in  wicker 
nests,  between  the  eye  and  the  blue  of  the  firma- 
ment*. 

As  this  theory  is  but  indirectly  connected  with 
our  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  eiuHTierate  more  instances  in  which  the  prin- 
ciple fails  than  holds  good.  Gloger's  instances  also 
are  far  from  accurate ;  for  though  the  kingfisher, 
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  animals,  can  see  with  the  least  possible 
light.  Many  birds,  also,  which  lay  bright-coloured 
eggs,  make  open  nests;  the  thrush,  ibr  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  {Fringilla  chloris,  Temminck), 
*  See  also  St.  Pierre,  Studies  of  Nature,  ii.  393 ;  Note. 


COLOURS    OF    ECGS.  35 

again,  which  builds  an  open  nest  of  green  moss, 
lined  with  horsehair,  black  or  white  as  it  can  be 
had,  laj^s  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  always  builds  in 
holes  or  under  cover.  These  objections  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 
fire-tail. 

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  Urticfe), 
the  peacock  (F.  lo),  and  the  admirable  {F.AtaIa?ita), 
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  {Apatela  Le- 
porina.,  Steph.),  which  are  deposited  on  the  grey 
bark  of  the  willow,  are  light  purple;  the  beautiful 
geometric  moth  {Geometra  illmiaria),  which  Sepp  * 
calls  Hercidesje,  lays  its  light  pink  eggs  in  the  fissm-es 
of  the  bark  of  the  elm  ;  the  puss  moth  {Cerura  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 
colewort  leaf,  but  not  of  so  bright  a  yellow  as  those  of 
the  seven-spot  ladybird  {CoccuieUa  Seplem punctata) . 
*  Sepp,  del-  Wondercn  Gods,  Tab,  35, 


H  INSECT   TRANSFORMATIONS. 

patches  of  which  may  be  found  on  many  sorts  of 
leaves  during'  the  summer  months. 

The  immediate  origin  of  colour  in  the  eg'o's  of  in- 
sects is  ill  some  cases  the  inclosed  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  driid^er  moth  {Odoncstis  potatoria),  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  proved  by  dissection  *.  Certain  ruddy 
spots  on  the  white  eggs  of  the  small  rhinoceros 
beetle  (Oryctes  7iasicor}iif},  Illiger)  were  discovered 
by  Suammerdam  to  be  the  red  mandibles  and  spi- 
racles of  the  unhatched  grub  seen  through  the  shell; 
and  the  white  ground,  we  infer,  was  similarly  caused 
by  the  body  of  the  grubt.  This,  however,  cannot 
be  the  origin  of  the  bright  red  spots  on  the  beautiful 
yellow  egg  of  the  brimstone  moth  {Rwnia  crat^gata, 
Duponchel),  which  may,  perhaps,  have  a  similar 
origin  to  those  of  birds. 

With  respect  to  the  eggs  of  birds,  it  has  been  re- 
marked by  Mr.  KnappJ,  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 
phoeniciirus,  Lath.),  and  of  the  hedge-sparrow, 
tliough  corroded  away,  is  not  destroyed  by  muriatic 
acid.  The  blue  calcareous  coating  of  the  thrush's 
vgg  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. 

f  Swammerdam,  Book  of  Nature,  i.  13. 
X  JouriKil  of  a  Naturalist,  p.  230 


SHELLS   OF    EGGS.  37 

the  film,  thoiin-h  loosened  and  rendered  miioilag'inous 
by  this  roni^h  process.  Though  this  calcareous  mat- 
ter is  partly  taken  up  during  incubation,  the  mark- 
iug's  upon  these  egg's  remain  little  injured  even  to 
the  last,  and  are  almost  as  strongly  defined  ;is  when 
the  eggs  are  first  iaiil.  These  circumstances  seem 
to  imply,  tliat  the  colouring  matter  on  the  shells  of 
eggs  does  not  contribute  to  the  various  hues  of  the 
plumage,  but,  il  is  reasonable  to  conclude,  are  de- 
signed 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  charac- 
teristic figuring." 

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  eQ;g,  provitled  for  the  nourish- 
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, 
opaque,  chiefly  composed  of  cha!k  (carbonate  of 
lime),  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  ((or  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 


^8  INSECT   TRANSFORMATIONS. 

goose-quill  in  the  eirn-s  of  the  drinker  and  other 
moths  which  we  have  dissected*;  b\it  in  the  eggs 
which  are  deposited  in  moist  places,  and  in  those  of 
spiders,  it  is  extremely  thin  f-  The  eg'gs  of  saw-flies, 
unts,  &c.,  which  grow  larger,^  as  we  shall  afterwards 
show,  durinp:  the  process  of  hatching',  mn^t  possess 
an  expansible  shell  to  allow  of  their  enlargement. 
The  yolk  and  white  in  the  eggs  of  birds  are 
separated  from  each  other  by  a  very  fine  membran- 
ous bag  in  which  each  is  contained ;  but  in  the 
eggs  of  msects,  what  answers  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  dispor),  which 
we  boiled,  still  continued  partly  fluid,  though  the 
brown  matter  answering  to  the  yolk  was  considerably 
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  (Cicatriciila)  in  the  eggs  of 
birds, — we  can  readily  distinguish  even  by  the  naked 
eye  in  the  larger  species  of  eg-gs,  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  underneatii  the  little  cloud.  The 
largest  presented  a  single  opaque  and  whitish  point 
*J   R.  f  Kirby  and  Spence,  Intr.  S6. 


GERMS  OF   EGGS.  39 

in  their  interior.  There  were  some  whose  whole 
body  was  so  remarkably  clear  as  to  allow  of  my  very 
distinctly  observing-  the  rings.  On  fixing-  attention 
more  closely  upon  the  latter,  I  observed  the  egg 
open,  and  the  larva  appear  in  its  place.  Having 
compared  these  eggs  with  those  just  laid,  I  con- 
stantly found  the  latter  of  a  milky  whiteness,  com- 
pletely 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  elongat- 
ing they  become  transparent,  but  do  not  at  this 
time  disclose  the  form  of  the  grub,  which  is  always 
arched*." 

The  germ  in  the  es:g  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  the  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 
spiders  an  egg  appeared  to  have  a  considerable  num- 
ber dispersed  upon  different  points  of  the  surface; 
but  all  these  ultimately  united  into  a  single  germf. 

The  eggs  of  the  glow-worm  {Lampyris  iioctihica)^ 
as  we  ascertained  from  those  deposited  by  one  wliich 
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. 

f  Heroldt,  Exercit.  de  Generat.   Aranearum  in  Ovo,    and  bis 
Unterg.  iiber  die  Bildung  der  Wizbellosen  Thiere  im  Eie. 

d2 


40  INSECT   TRANSFORMATIONS. 

to  tlie  wax  of  the  ears,   and    in   form  of  i^ronules 
vvliich  are  even  externally  apparent*. 

We  are  accustomed  to  consider  the  form  of  eg-gs 
so  nearly  regular,  that  the  epithet  ''  eg'g  shaped"  is 
frequently  aj)pl;ed  to  other  things,  and  is  well  under- 
stood ;  but  the  eggs  of  insects,  though  most  com- 
monly 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  cylindrie,  flat,  depressed,  compressed,  prismatic, 
angular,  square,  boat-shaped  fi  &c.  These  varieties 
of  form  are  justly  referred  by  Kirby  and  Spence  to 
the  "  manifold  wisdom"  {7ro\v7roiKi\oQ  co^na)]:  of  the 
Creator ;  but  we  have  some  hesitation  in  admit- 
ting their  limitation  of  this  to  his  "  will  to  vary 
forms,  and  so  to  glorify  his  wisdom  and  power  in- 
dependently of  other  considerations §,"  and  think  it 
would  be  more  truly  philosophic  to  confess  our  igno- 
rance where  we  cannot  explain  what  is  above  our  com- 
prehension. Paley,  indeed,  says,  such  facts  "  might 
ijiduce  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  appetites, 
and  did  all  animals  covet  the  same  element,  retreat, 
or  food,  it  is  evident  how  much  fewer  could  be  sup- 
plied and  accommodated  than  what  at  present  live 
conveniently  together  and  find  a  plentiful  subsist- 
ence ||."  The  latter  remark,  we  think,  completely 
destroys  the   former,   and   it  wi'U   lead   us  to    what 

*  J.  R. 

t  Dumeril,  Consider.  Generales,  p.  49;  and   Insect  Architec- 
ture, p.  19. 

X  Kphes.  iii.  10.  ^  Introd.,  ill.  p.  95. 

II  N  Plural  Theology,  p.  345,  14th  ed. 


FORMS    OF    EGGS.  41 


appears   to  be  the  true  cause  of  the  varied  forms  of 
'  the  e<j;gs  of  insects. 


Eggs  of  a  battel  dy  and  of  a  moth,  magnified. 

The  cause  of  the  eg-gs  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,  ditFer  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 
shaped  like  a  Florence  flask,  and  quite  smooth  and 
uniform*. 

The  ribbing  of  the  eggs  of  the  small  tortoise-shell 
*  Sepp,  dev  Woiidcrcn  Cods,  Tab.  ii.  and  viii. 


42 


INSECT   TRANSFORMATIONS. 


butterfly  {Vanessa  uHIccb),  which  is  also  found  on 
those  of  most  of  the  species,  leads  us  to  remark  that 
insect  egi^s  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  mi- 
croscope, remind  us  of  the  fine  crustaceous  shells 
called  sea-eggs, — a  resemblance  which  is  well  exem- 
])lified  in  the  eg^  of  the  angle-shades  moth  (PhlogO' 
phora  meticulosa,  Stfphens),  as  compared  with  the 
Clypeaster  of  Parkinson. 


a,  raagnitied   egsj  of    the  iinijle-shades  moth  {^Fhloguphora  meticu- 
lusa);  6,  sea-egg  (^Clypeaster^,  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  Jurtina)  is  crowned  at 
the  upper  end  with  sculptured  work  in  the  form  ot 
tiles  or  slates,  as  if  to  defend  it  from  injury,  while 
others  are  covered  with  a  sort  of  net-work  of  ex- 
tremely minute  six-sided  meshes. 


FORMS    OF    EGGS. 


43 


a,  the  egg  of  the  meadow  brown    butterfly,  magnified;  h,  egg  of 
the  brimstone-moth  (^Rurnia  Cratcegata),  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  Svvammerdam  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  (Ncpa  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 
sMCcessively  in  the  bosom  of  the  down  of  the  one 
next  to  it.  As  the  mother  insect  deposits  these  eggs 
in  the  stents  of  aquatic  plants,  the  bristles,  which  are 
partly  left  on  the  outside,  are  probably  intended  *X) 
*  Swannn    Book  of  Nature,  i.  104. 


44 


INSECT   TRANSFORMATIONS. 


prevent  the  aperture  from  being  closed  up  by  the 
rapid  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 
tlie  parent,  while  they  are  permitted  to  enter  suffi- 
ciently far  to  preserve  them  moist.  Both  circum- 
stances are  indispensable  to  their  liatching ;  for 
when  Reaumur  took  them  out  of  the  dung,  they 
siirivelled  up  in  a  few  hours,  and  when  he  immersed 
tiiem  farther  than  the  two  pegs,  they  were  suffocated, 
and  could  not  afterwards  be  hatched*. 

d 


a,  Dung  fly  (Scafuph'iga  Sterroran'a') :  be,  fro  if  and  side 
views  of  its  eggs  ir.agnitied;  d  d  d,  a  lumber  of  tlv  se  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  sur]irise,  that 
these  are  the  eggs  of  the  lace-winged  fly  (Chrysopa 
reiicvlata.  Leach).  Reaumur  says  that  several 
naturalists  have  described  them  as  fungi,  which  is 
!U)t  to  be  wondered  at;  for  they  consist  of  a  small 
oval  grt'cnish-white  head,  similar  to  the  apple-mould, 
*  Reaumur,  iv.  379 


POSITION    OF    EGGS.  j.>, 

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  spider  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  nearly  of  equal  length.  It  is  evi- 
dently the  design  of  these  footstalks  to  place  the  eggs 
out  of  the  reach  of  the  grubs  of  lady-birds  {Coc- 
cinellce)   and  of  aphidivorous  flies  {Syrphi),  which 


Twig  of  lilac,  bearing  the  ep;gs  of  the  lace-wingcd  fly  (^CUrysopa 
reticulata,  Leach}.    The  fly  is  seen  resting  on  the  lowest  leaf. 


46  INSECT   TRANSFORMATIONS, 

frequent  the  same  situations  and  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 
deposits  eggs  with  a  footstalk  ;  and  what  is  most 
singular,  these  larvae,  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 
formed  her  cocoon  that  they  devour  her,  and  spin 
their  own  cocoons  under  its  coverf. 

The  eggs  of  insects  do  not  seem  to  hold  any 
regular  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  consider- 
ably larger.  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  ajjpears  to  hold  to  a  certain 
extent  amongst  insects,  the  most  prolific  families 
belonging,  with  ie\w  exceptions,  to  those  which  devour 
vegetable  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  (Lihellu' 
Una,  Mac  Leay)  do  not  lay  above  two  dozen  eggs, 
the  lace-winged  flies  (Hcmerobidts)  still  fewer,  and 
the  noontide  fly  {Mcsembrina  meridiana,  MiiiGEN) 
*  J.  K.  t  See  Insect  AiciiUecturc,  pp.  195—325,  6. 


FECUNDITY   OF   INSECTS   AND    FISHES.  47 

only  deposits  two  egs;s ;  while  a  sinpjle  plant-louse 
(^Aphis)^  as  we  mentioned  before  from  Rt?aiimur, 
may  be  the  living  progenitor  of  5,904,900,000  de- 
scendants, and  the  queen  of  the  warrior  white  ants 
(Termesbellicosus^S^iEXinm.)  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.  "  Compared  with  the  rest  of  ani- 
mated nature,"  says  Dalyell,  "  infusion  animalcula 
are  surely  the  most  numerous :  next  are  worms,  in- 
sects, or  fishes  ;  amphibia  and  serpents,  birds,  quad- 
rupeds ;  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, 
inferior  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  Qg^ 
at  a  time.  How  prodigious  is  the  ditFerence,  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  1100.  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 
ascarides.  One  naturalist  found  above  12,000  eggs 
in  a  lobster,  and  another  above  21,000.  An  insect 
very  similar  to  an  ant  {Mutilla?)  has  produced 
80,000  in  a  single  day ;  and  Leeuwenhoeck  seems 
to  compute  four  milHons  in  a  crab.  Many  fishes, 
and  those  which   in   some  countries  seldom  occur 


48  INSECT   TRANSFORMATIONS. 

produce  incredible  numbers  of  eg-g-s.  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  species  of  sturgeon;  342,000  in  a  carp; 
383,000  in  a  tench;  546,000  in  a  mackerel;  992,000 
in  a  perch  ;  and  1,337,000  in  a  flounder.  But  of  all 
fishes  hitherto  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,  tiien,  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  extraor- 
dinary fecundity  which,  under  favourable  circum- 
stances, produces  countless  swarms  of  insects  that 
give  origin  to  the  opinion  of  their  being  sponta- 
neously 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  eg;g  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  numerous. 

*  Introd.  Observ.  to  Spallanzatii,  xiv. 


49 


Chapter  III. 


Maternal  Care  of  Insects  in  depositing:  their  Eggs.— Solitary  Bees.— 
Wasps. — Ichneumons. — Moths.— Butterflies.— Gnats. — Mistakes  of  Iii» 
stinct. 


Lord  Kaimes,  in  his  '  Gentleman  F'armer,'  men- 
tions the  sino'ular  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,  thcieibre,  has  endowed  female  insects 
with  the  most  wonderful  acuteness  and  skill  in  anti- 
cipating the  wants  of  their  young,  when  they  escape 


60  INSECT   TRANSFORMATIONS. 

from  the  egs;,  and  have  no  mother  to  direct  or  pro- 
vide for  them. 

We  have  numerous  beautiful  instances  of  this  in 
the  solitary  bees  and  wasps,  whicli  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,  {Chclostoma  j^orisoiruie?)  not  so  large  as  the 
domestic  fly,  and  more  slender  in  the  body,  instead 
of  digging  into  the  ground  like  its  congeners  t, 
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  {Anobium  ]jer- 
tinax),  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  grey  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  jit  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  (X3//0- 
copa),  they  were  divided  by  several  partitions  of  the 
same  membranous  material. 

The  circumstance,  however,  which  induces  us  to 
give  these  details  here,  relates  to  the  eggs  deposited 

♦  See  Insect  Architecture,  pp.  24 — G4,  &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 
stai;e  of  its  existeTice.  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  researches  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  sur- 
face, 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  stretched  its 
head,  when  feeding,  to  the  centre,  instead  of  eating  at 
the  circumference.  The  honey  was  also  then  be- 
come thicker  in  consistence,  and  in  consequence  of 
what  had  been  consumed,  formed  a  hollow  cup*. 

Remimur  describes  the  nest  of  a  bee  of  the 
same  family  {Andrena  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  eg:g  is  placed  above  the  surface  of  the  fluid 
honey  t. 

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. 


f)2  INSECT    TRANSFORMATIONS. 

tering;  the  youno-  grub  from  the  inclemencies  of  the 
weather,  or  from  beinjr  preyed  upon  by  birds.  There 
are  more  insiduons  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  Ichnemnons,  a  name  signifying 
Pryers,  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 maimer  would  appear  almost  incredible  to  one 
who  had  not  studied  their  economy  ;  but  it  cannot 
fail  to  meet  the  young  entomologist  at  the  vei)" 
*  Phil.  Trans,  for  1788,  p.  21  "J. 


PRECAUTIONS   OK    INSECTS.  53 

outsetof  his  studies;  for  it  is  scarcely  possible  for  many 
broods  of  insects  to  be  reared  without  observing'  it. 

The  insidious  proceedings  of  these  cuckoo  in- 
sects, as  we  may  not  inappropriately  call  them,  give 
rise  to  remarkable  displays  of  ing-enuity  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  fe- 
male, 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  Chryds  or  Tachina  often  glides  into  her 
domicile,  and  finds  time  to  deposit  its  egg  and 
to  escape  before  her  return.  Other  solitary  bees  ex- 
hibit both  more  civilization  and  more  culining;  for 
the  male  assists,  al  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  fulvoci?ictufi,  Steph,),  indigenous  in  the 
vicinity  of  London,  has  frequently  t'allen  under  our 
observation.  It  constructs  a  gallery,  having  on  the 
outside  only  a  single  perpendicular  passage,  but 
branching  out  into  seven  or  eight,  at  the  bottom  of 
each  of  which  is  placed  a  globule  of  pollen  kneaded 
up  with  hont  y  about  the  size  of  a  pea,  where  an  egg- 
is  deposited.  Walckenatr,  who  observed  these  in- 
I  sects  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 
I  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  often  seen, 


a4  INSECT   TRANSFORMATIONS. 

indeed,  the  ruby-tail  fly  {Chrysis  ignifa),  on  ap- 
proaching this  vigilant  sentinel,  fly  off  in  all  haste, 
with  evident  fear  of  the  consequences.  But,  as 
Walckenaer  justly  remarks,  should  the  partner  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  i'rom 
its  post,  and  the  forager  enter  without  announcing 
its  arrival,  it  is  immediately  driven  back  and  punished 
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  ornata),  numbers  of 
which  make  their  nes's  in  the  very  midst  of  their 
colonies.  The  wasps  surround  the  interior  margin 
of  their  holes  with  a  ramjjart  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  ^oov  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- 
*  VValck.  Mem.  dcs  AbciUes  Sulit.     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 
j  it,  but  not  to  kill  it  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 
mirita,  Latr.,  and  C  qitadrifasciatay  Bosc)  are 
of  essential  service  to  agriculturists  by  provisioning 
their  nests  with  destructive  weevils  (^Curculioiiidce) ^ 
so  injurious  to  orchards  and  nurseries  f-  Other 
famihes  of  this  order  in  a  similar  way  provide  for 
their  progeny  a  supply  of  living  insects  of  ditferent 
species,  of  which  interesting  accounts  have  been 
given  by  more  than  one  naturalist  |. 

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- 

*  Wa'.ck. ;    Latreille,  Annates  du    Museum,   torn,   xiv.;    and 
Bosc.  Ann.  Je  I'Agric,  vol.  liii. 
t   Bosc,  Ann.  de  I'Agric,  vol.  liii. 
I  Sec  Insect  Architecture,  pp.  26—33.     §  Ibid.,  pp.  30—32. 


56  INSECT   TRANSFORMATIONS. 

dious  intrusion  of  a  common  ichneumon-fly  (Pimpla 
manifestator,  G  raven horst),  easily  known  by  its  be- 
ing black,  with  the  legs  red.  This  ichneumon  some- 
times 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  yomig  one,  closes  up  the  doorway  with  a  bar- 
ricado  of  kneaded  clay.  It  is  this  very  barricado 
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  as  those  of  the  saw  flies  or 
the  tree-hoppers  {CicadcB). 

The  ovipositor  of  all  the  true  ichneumons  {Ich- 
nemnonidce)  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.  incniifesiator)  will  be  sufficient  to 
give  the  reader  a  distinct  notion  of  the  others. 
l?eing  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  perpendicuhir,  a  structure 
better  fitted  for  acting  upon  clay,  as  the  teeth  will 
not  become  so  readily  clog-g-ed,  and  the  instrument 
will  be  more  easily  retracted.  The  figures  will  make 
this  more  perspicuous  than  the  best  description. 


a,  the  Pxmpla  mmrfestntor ;  b,  its  ovipo>itor  opened  outwaivU; 
c  c  c  c,  magiiilied  view  of  its  ovipositor  ;  d,  the  tootiied  point  of 
the  borer. 

In  order  to  study  the  economy  of  the  mvaon- 
wasps  {(Jdyncri)  more  effectually,  Reaumur  made 
an  artificial  vespiary  of  sand  and  mortar  upon  a 
wall,  which  at  the  same  time  gave  him  'j^n  excellent 
opportunity  of  observing  the  manoeuvres  of  the  ich- 
neumons. ''  I  perceived,"  he  tells  us,  "  one  of  these 
ichneumons,  at  the  instant  it  alighted  on  the  spot 
under  which  so  many  of  the  little  green  caterj)illars 
had  been  stored  up  by  the  wasps.  Its  long  tail, 
which  it  carried  horizontally,  appeared  to  form  but 
0!ie  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  proporiions  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  barri- 


58 


INSECT  TRANSFORMATIONS. 


cadoed  nest  of  the  mason-wasp.  But  although  the 
insect  appeared  not  to  he  disturbed  by  my  obser- 
vations, yet  I  was  unable  to  perceive  whether  the 
toothed  portion  of  the  borer  was  pushed  beyond  the 
sides  of  the  sheath.  What  I  did  see,  however,  con- 
vinced me  that  the  instrument  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.  h  h,  its 
ovipositor,  c,  an  ichneumon,  which  has  just  bored  through  the 
closed  substance  of  a  sand-wasp's  nest  at  e,  into  which  her  ovi- 
positor, d,  descends  to  the  coil  of  caterpillars  at  /,  where  the 
egg  is  laid. 

*  Reaumur,  Mem.  vi,  p.  3l)4. 


PARASITE-EGGS.  59 

Another  parasite   (Pimpla   strobilellfB,  Fabr.)  is 
F    armed  witli  a  long  ovipositor,  with  which  it  deposits 
its  etrgs  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  {ChalcidideBy  Westwood). 
When  the  gall-fly  {Cynips^  has  deposited  its  eggs  on 
the  bud  or  the  leaf  of  a  plant  in  such  a  manner  as  to 
ensure  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 
i  or  bedeguar  of  the  rose*.  The  most  obvious  dis- 
tinction 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  fancii'ul 
notion  of  their  being  generated  by  a  vegetative  and 
sensitive  soul  in  the  plant  itself,  to  which  also  he 
attributed  the  generation  of  the  grubs  found  in  nuts, 
cherries,  and  other  fruits.  ''  There  is  nothing,"  as 
Reaumur  justly  remarks,  *'  more  fitted  to  humi- 
liate the  best  reasoners,  and  to  inspire  them  with  a 
*  See  Insect  Architecture,  pp.  375 — 384. 


I 


60  INSECT   TRANSFORMATIONS. 

well-founded  distrust  of  novel  opinions,  than  to  see 
a  man  like  Redi,  who  had  declared  open  war 
a2;ainst  popular  prejudices,  and  successfully  com- 
bated many  of  them,  thus  adopting-  a  notion  so 
improbable,  or  (to  use  a  stronger  term)  so  pitiable*." 
It  was  Redi's  countryman,  Malpighi,  who  first  dis- 
covered 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  bedcguarU, 
and  Eurytoma  stigma,  Stephens)  are  parasites, 
Redi  had  some  cause  foi  being  puzzled  to  explain 
the  ])henomena. 

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,  fiom  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  stoj)ped  short,  and  formed  them 
into  insects  of  a  smaller  size,  and  less  perfect  struc- 
ture f.  M.  Goedart  even  persuaded  himself,  says 
Reaumur  sarcastically,  that  he  had  observed  the 
caterpillar  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  witii  tlie  expected  biitterfiy, 
was  made  up  in  their  greater  numbers |  ;  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.  4/6. 

f   Ray,  tiist.  Ins.,  I'ref.  xv.,  and  Cant.  137. 

I  Goedaitj  quoted  by  Reaumur,  vol.  ii.  p.  415. 


PARASITE-INSECTS.  61 

It  must  have  occurred  to  the  least  attentive 
observers  of  the  very  couiinon  cabbage-caterpillar 
{Pontia  BrassicfB)^  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  (Micro- 
gaster  gloineratus,  Spinola),  of  a  black  colour,  ex- 
cept the  legs,  which  are  yellow.  By  breeding  these 
flies  in  a  state  of  confinement,  and  introducing  them 
to  some  cabbage-caterpillars,  their  proceedings  in  de- 
positing tlieir  eggs  may  be  observed.  We  have  more 
than  once  seen  one  of  these  little  flies  select  a  cater- 
pillar, and  perch  upon  its  back,  holding  her  ovipositor 
ready  brandished  to  plunge  between  the  rings  which 
she  seems  to  prefer.  When  she  has  thus  begun 
laying  her  eggs,  she  does  not  readily  take  alarm ; 
but,  as  Reaumur  justly  remarks,  will  permit  an  ob- 
server to  approach  her  with  a  magnifying  glass  of  a 
very  short  locus.  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 
anotiier  caterpillar  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  disagreeable. 

The  eggs,  it  may  be  remarked,  are  thrust  suffi- 
ciently deep  to  prevent  their  being  thrown  off  when 
the  cateipillar  casts  its  skin  ;  and,  being  in  due  time 
hatched,  the  grubs  feed  in  concert  on  the  living 
body  of  the  caterpillar.    The  most  wonderful  circuUi- 

£ 


62 


iNSECT   TRANSFORMATIONS. 


stance,  indeed,  of  the  whole  phenomenon,  is  the 
instinct  with  which  the  grubs  are  evidently  g:uided 
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  c^rown,  they 
even  eat  their  way  through  the  skin  of  the  cater- 
pillar without  killing  it ;  though  it  generally  dies  in 
a  few  days,  without  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  a,  the  cateriiillarof  Pontin  Bran- 
siccv.  b.  the  efifgs  of  that  buttertly  glued  to  a  leaf,  c,  Mieroijastev 
glomrrntus,  inapnifiei].  d  d  d,  a.  niagniticd  view  of  a  disstcted 
caterpillar,  in  whose  body  a  number  of  ichneumon  cater[)illars 
have  been  hatched,  e,  silk  cocoons  spun  by  tlie  ichneumons. 
/.  prubs  spinning  cocoons,  g,  grubs  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 
mothers  contrive  to  deposit  their  eggs ;   for  many  of 
them  are  so  very  minute,  as  to  find  in  the  egg-s  them- 
selves of  larger  insects  a  sufficient  magazine  of  ibod 
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    remarked    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 
{Muscid(Ey  Leach),  also,  outbrave  the  danger  of  being 
caught  and  immolated  by  the  mother  spider,  and 
introduce  their  eggs  either  into  or  among  those  of 
their    powerful    enemy.      These    spider's    eggs    are 
subsequently  feasted  upon  by  the  progery   of  the 
flies, — a  very  natural  reprisal   for  the  ravages  com- 
mitted by  this  carnivorous  race  upon  the  whole  gene- 
j  ration  of  their  fellows.     That  the  mother  flies  actually 
■I  pierce  the  eggs  of  other  insects  was  observed  before 
I!  the  year  1730,  by  the  accurate  Vallisnieri,  who  says, 
I   '*  I  have  seen  with  my  own  eyes   a  certain  kind  of 
\  wild  flies   deposit  their  eggs  upon  other  eggs,  and 
[l  bore  and  pierce  others  with  an  ovipositor  {acnUusi)^ 

!j  by  means  of  which  they  have  introduced  the  egg*." 
j  Count  Zinanni,  another  Italian  naturalist,  told  Reau- 
j  mur,  that,  his  attention  being  attracted  by  a  small 
fi  ichneumon  fluttering  about  the  eggs  of  butterflies, 
1.}  he  soon  observed  it  alight  and  fix  upon  one  of  these 
|i  eggs;  and,  without  being  incommoded  by  his  ol)- 
\[  serving  her  proceedings  through  a  strong  magnitier, 
;  *  Vallisnieri,  I.elteie,  80. 


64  INSECT   TRANSFORMATIONS. 

she  bent  her  ovipositor,  and  plunged  it  into  the 
effg.  She  performed  the  same  operation  upon  many 
other  eggs,  which  he  carefully  put  under  cover;  and 
in  about  tliree  weeks  had  from  them  a  brood  of  flies 
of  the  same  species  with  the  one  whose  remarkable 
j)roceedii!gs  he  had  watchetl*. 

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  {Platyga.'iter  oviilorvm?  Stephens), 
which  was  produced  from  the  caterpillars  of  the  larae 
white  cabbage-butterfly  (Poniia  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  ])roceeds,  "  I  found  them 
resting  on  large  clusters  of  minute  cocoons  of  an 
ovate  form,  tlie  largest  not  exceeding  two  lines  in 
length,  and  about  the  thickness  of  a  caraway-seed. 
Each  was  enveloped  with  a  fine  yellow  silk,  re- 
sembling that  of  the  common  silkworm  {Bombyx 
Mori).  On  these  clusters  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 
liad  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  f."  Jt  is 
not  a  little  interesting  to  remark,  that  this  circum- 
stance corroborates  the  statement  before  given  from 

•   lluaumur,  Mem.  vol.  vi,  p.  297. 
f   Loutlon'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  up- 
wards 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  {Microgaster  glomeratus) ;  but,  supposing 
them  to  be  in  the  first  instance  e^g  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  Aphidum,  Spinola),  which 
plunges  its  eggs  in  their  bodies;  but  the  larva?, 
when  hatched,  are  by  no  means  safe,  being  liable 
to  the  attacks  of  another  fly  of  the  same  family 
(Gelis  agilis,  Thunberg),  as  Dr.  Turton  informs 
us  f. 

*  Bonnet,  GEuvres,  8vo.  ii.  344.     Kirby,  referring  to  this  pas- 
sage, assigns,  by  mistake,  only  two  to  each  egg.     Introd.  i.  342. 
f  Transl.  of  Linn.  iii.  48. 

e3 


GB  INSIiCT    TRANSFORMATIONS. 

It  is  not  comnioii,  however,  for  the  ichiieuinon- 
flies  to  deposit  their  eggs,  in  the  bodies  of  perfect 
insects,  as  in  most  cases  they  prefer  the  egg-s,  larvie, 
or  pupae ;  but  instances  are  on  record  of  their  grubs 
having  been  found  in  the  former.  The  troublesome 
cock-roach  {Blattd)  is  selected  by  a  parasite-fly 
(Evania  apendigaster,  Fabu.),  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  {Andrena  nigro^nea,  Stephens).  "  I  had  pre- 
viously,'' he  remarks,  "  more  than  once  observed 
upon  other  species  something  that  I  took  to  be  a  kind 
of  Acarus,  which  appeared  to  be  immoveably  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 
iiad  mistaken  for  an  acariis !  {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  1  had 
drawn  it  out  but  a  little  way,  £  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  anitnal  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  seem.ed  dubious*."  Of  the  manner  in  which 
this  singular  insect  {Stylojjs)  introduced  its  eggs 
into  the  body  of  a  bee  nothing  is  yet  knoA'n,  and  its 
rarity  i)uts  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  MelittcB,  Kiubv.) 

De  Geer    was   one    day    much    surprised    to    ob- 
serve a  small  white  grub  sucking  the  body  of  a  young 
spider    {Epeira    diadcmd),    having    attached    itself 
*  Monogr.  Ap.  Angl.  ii.  113. 


68  INSECT   THANSFORMATIONS. 

firmly  to  the  abdomen.  Having-  pnt  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  circuhir  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  tlieir  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 
same,  or  similar  substances,  as  her  larvte,  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  tlieir  eggs  on  plants  and 
trees  where  their  young  may  eat  abundantly  of 
leaves  or  other  parts  "  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  indilferently  of 
two  or  three  sorts;  while  others  take  a  wider  range, 
and  fix  upon  plants  of  very  ditferent  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  but- 
terfly {Vanessa  urticce)  on  any  plant  but  the  nettle  ; 
its  congener,  the  painted  lady  (Cynthia  cardui, 
Stephens),  though  it  prefers  the  spear- thistle,  is 
sometimes  found  on  the  nettle,  as  is  the  comma 
{Vanessa  C.  Album),  though  it  seems  to  prefer  the 
hop  ;  while  we  have  found  the  eggs  of  the  lackey- 
moth  {Clisiocampa  neustria)  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  {Arctia  Caja,  Ste- 
phens), will  as  readily  select  the  nettle  as  the  lettuce 
or  dandelion*. 

It  is  worthy  of  remark  that  our  native  insects 
frequently  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  {Acherontia  Atropos),  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  {Sola nnm 
dulcamara).  W^  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 


70 


[NSECT   TRANSFORMATIONS. 


was  transformed  within  the  leaf,  in  a  few  days,  into 
a  pupa,  and  being  put  under  a  belt-glass,  a  small  two- 
winged  fly  (Tephritis  SerratulcB?)  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  Scrratulrv ?). 
b,  mined  leaf  of  sow-thistle  (^Sonchus  oleraceus').  i\  mined  leaf 
of  Senecio  elegans.    d  d.  mined  leaf  of  Cineraria  cruanta. 


LOCALITIES   OF    VARIOUS    SPECIES.  71 

immerous  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  {Co7npositce)  ;  yet,  notwithstanding  the  simi- 
larity of  the  common  groundsel  (Saiecio  vulgaris)  to 
the  American,  not  one  leaf  of  the  former  was  found 
mined,  thoug-h  it  is  an  abundant  native  plant*. 

It  is  no  less  remarkable,  that  the  mother  insects 
of  the  larvae  which  live  solitary  and  those  which  live 
in  society  take  care  to  deposit  their  eggs  with  regard 
to  the  respective  destinations  of  their  progeny.  In 
our  earlier  studies  we  remember  being  much  inte- 
rested with  Harris's  description  of  the  admirable 
butterfly  {Vanessa  Atalanta)^  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  f.  Our  subsequent 
observation  of  the  manners  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 
mothers  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  {Sphingid(B^ 
Leach),  yet  we  have  found  from  two  to  three  eggs  of 
that  of  the  poplar- 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  +  ;  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  similan' 
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-vving  {JEgtria  asiliformis),  above  a  score 
of  the  small  black  eggs  of  which  we  tbund  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  exem- 
plified in  the  common  gnat  {Cule.v  pipiena,  Linn.). 
It  is  admirably  described  by  Reaumur,  though  it 
seems  first  to  have  been  discovered  by  Langallo,  who 
mentions  it  in  a  letter  addressed  to  Redi,  printed  at 
Florence  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  opera- 
tion must  repair  before  five  or  six  o'clock  in  th€ 
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-  i 
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  Goldsmith, 
"  in  which  the  insect  lays  its  eggs  is  particularly 
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  sink- 
ing, 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  othei 
where  the  water  may  be  too  cold,  or  the  animals,  its''^' 
cuemies,  too  numerous.  Thus  the  insects,  in  theiif 
*  J.  R. 


RAFT  OF  EGGS  OF  THE  GNAT.        73 

ogg  state,  resemble  a  buoy  wliich  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  bottoiri^y  This  fable,  which  was  first  men- 
tioned by  Pliny,  is  repeated  verbatim  by  Bing-leyf 
The  impossibility  of  a  g-nat  spinning  a  thread,  and 
plunfring  into  the  water  to  fix  it  at  the  bottom,  never 
struck  these  writers. 

We  are  the  more  anxious  to  expose  these  erroneous 
accounts,  from  a  persuasion  that  a  tas'te  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  tbrm  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  a  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 
etich  side  of  this  egg  she  places  another,  all  which 
adhere  firmly  together  by  means  of  their  glue,  and 
jform  a  triangular  figure  thus  **,  which  is  the  stern 

*  Goldbinilh,  Animated  Nature,  vi.  337. 
I   Bingley,  Animal  Biography,  iii.  439,  3d  ed. 

F 


74 


INSECT   TRANSFORMATIONS. 


of  the  raft.  She  proreeds  in  the  same  manner  to  add 
eg^  after  egg  in  a  vertical  (not  a  horizontal)  position, 
carefully  regulating-  the  shape  by  her  crossed  logs;  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;  b,  the  boat  about  two-thirds  completed;  c, 
the  perfect  boat  resting  ou  the  surface  of  the  water. 

Kirby  justly  describes  this  little  vessel  as  resembling 
a  London  wherry,  being  sharp  and  higher,  as  sailors 
f>ay,  fore,  and  aft,  convex  below  and  concave  above,  and 
always  floating  on  its  keel.  "  The  most  violent  agita- 
tion of  the  water,"  he  adds,  "  cannot  sink  it,  and  what  is 
more  extraordinary, and  a  property  still  a  desideratum 
in  our  life-boats,   though  hollow,   it  never  becomes 


Reaumur,  Me 


111.  IV.  p, 


G21. 


RAFT  OF  EGGS  OF  THE  GNAT.        75 

filled  with  water,  even  though  exposed.  To  put  this 
to  the  test,  1  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  repeatedly  pushed 
them  to  the  bottom  of  a  glass  of  water,  but  they 
always  came  up  Immediately  to  the  surface  appa- 
rently 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 
displayed  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 
impress  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  peculiarities 
are  displayed.  The  infallibility  of  the  instinct  of  in 
sects  in  such  cases  is,  in  most  books  of  natural  his- 
tory, maintained  to  be  without  exception.  "  Led  by 
an  instinct,"  say  Kirby  and  Spence,  "  far  more  un- 
•  Introd.  iii,  p.  32 

f2 


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  vnerring  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 
lledi  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,  thekrubut,  of  Sumatra, 
(Rqfflesia  Aruoldii^  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,  and  apparently 
laying  their  q£!i<^^  in  its  substance,  mistaking  it  most 
probably  for  carrion,  as  it  smelt  like  tainted  beef|. 
A  similar  mistake  is  committed  in  our  own  country, 
when  the  common  blow-fly  {Miisca  vomiloria)  lays 
its  eggs  in  the  foetid  funguses  {Phalli,  Agarici^  &c.) 
apparently  under  the  notion  that  these  are  genuine 
carrion  §.  This  may  be  more  particularly  observed  I 
on  the  singular  class  of  plants,  stapdias,  which  are  I 
so  common  in  our  hot-houses:  whole  families  of 
maggots  are  constantly  born  to  starve  in  their  foetid  Ij 
flowers. 

These  are  instances  of  the  mistakes  of  instinct  in  i 
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 

*  Iiitrod.  i.  p.  340.  t  Ibid.  iii.  p.  65 

;  R.Brown,  Linn.  Trans,  vol.xiii.     ^  Smellie,  Thilos.of  Nal.  Hist. 


MISTAKES   OF   INSECTS.  77 

i  would  be  certain  to  deceive  the  inexperienced  ;  and 
Majendie's  servant  actually  fell  an  immediate  vic- 
tim to  her  desire  of  tasting  the  prussic  acid  which 
she  found  in  his  laboratory.  This  would  be  consi- 
dered perhaps  a  mistake  arising  from  the  artificial 
habits  acquired  in  society,  by  those  who  maintain 
that  animals,  guided  by  instinct,  never  mistake  poison 
for  food.  But  w^e  may  add  another  curious  instance 
or  two  of  similar  mistakes  in  the  inferior  races. 

The  common  earth-worm  (Lumhricus  ttrrestris) 
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  ap- 
proaching 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  a  stake  into  the  ground,  and 
moving  it  backwards  and  forwards,  to  imitate  the 
advance  of  a  mole  burrowing  in  search  of  prey. 
1  The  worm,  unable  from  its  instinct  to  discriminate 
!  between  its  subterranean  enemy  and  the  spade,  darts 
I  into  day-light,  and  is  instantly  captured  for  the  boy's 
i  bait-bag.  The  lapwing  {Vaiiellus  cristafus,  Meyer), 
it  is  stated  by  Dr.  Anderson  in  his  '  Bee,'  is  aware 
of  this  instinctive  fear  in  the  earth-worm  of  sub- 
terranean concussions  or  noises  ;  and  when  it  can- 
not find  sufficiency  of  slugs*,  &c.  above  ground, 
it  pats  with  its  feet,  till  the  earth-worms,  mistaking 
it  for  an  advancing  mole,  come  forth  to  be  feasted 
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,  fop  the  purpose,  as  may  be  supposed, 
of  distracting  his  attention,    on    the    principle    that 

*"  Nourriture  ; — insectes,  aralgii6e.s,  vers,  el  petits  lima^ons." 
Temm'.nck:,  Manuel  d'Ornilhologie,  p.  552,  2d  edit 


78  liNSECT   TRANSFORMATIONS. 

*  wealth   makes  wit  waver.'     Be  this  as  it  may    the 
cuckoo,    which    bears   a    strong    resemblance    to    a  • 
hawk  when   on   the  wing,  is  certain  to    be  accom- 
panied by  a  similar  retinue  of  small  birds  wherever 
it  flies.     In  the  north  this  is  so  commonly  observed, 
that  the  cuckoo  is  popularly  believed  to  be  always 
attended  by  a  titling  or  pippet   (Anthus  pratcnsisj 
Bechstein),  which  it   is  further  imagined,  has  been 
its  stepmother  and  nurse  from  tiie  ^g^:  this,  indeed, 
is  the  bird   whose  nest  the  cuckoo  most  frequently 
selects  to  deposit  the  eggs,  which  she  so  strangely 
and   unnaturally  abandons  ;   though  it  is   more  pro- 
bable that  it  is  not  on  this  account,  but  because  she  ; 
appears  to  be  a  hawk,  that  the  pippet  and  other  small  I 
birds  persecute  her. 

Linnaeus   records   in    his    '  Lachesis   Lapponica,* ' 
that  at  Tornea  there  is  a  meadow,  or  bog,  full  of} 
water-hemlock     (Cicuta    virosd)^    which     annually  f 
destroys  from   fifty  to  a  hundred  head  of  cattle.     It 
seems  that  they  eat    most  of  it  in  spring,  when  first 
turned   into  the  pasture,   partly  from  their  eagerness 
lor  fresh  pasture,   and  partly  from  their  long  fasting 
and  greediness,   the  herbage  being  then  short.     Be- 
sides,   from   the  immersion   of  the    hemlock    under 
water,  it  may   not   have   the  proper  scent  to  deter 
them.     A  similar  destruction  of  cattle  from  the  same 
cause  occurs  in  the  wide  meadows  of  Leinings  *, 

*  J.  R.,  in  Mag.  of  Nat.  Hist.,  i.  374. 


79 


Chapter  IV. 

Hy'ieriiatiouof  Inse(;t  Eggs. — Ingenuity  of  Moths. — Singularities  of  Co- 
chenille  Insects  and  of  Spiders. — Kxperiments  of  Spallanzani  and  John 
Hunter. 

The  assertion  of  Paley  that  "  the  human  animal  is  the 
only  one  which  can  clothe  itself*,"  though  it  accords 
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  t.  Men,  indeed,  proceed  by  means  of  rea- 
soning and  experiment  to  the  discovery  of  such  ma- 
terials as  are  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  (^Aria's 
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 
^gg.  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  Iter  body  thickly  clothed  witli  a 

*  Natural  Theology,  p.  230,  11th  edit. 
f  See  '  Insect  Architecture,'  chaps,  x.,  xii.,  &c. 


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  co- 
vering 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.  Without  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  opera- 
tions 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- 


INGENUITY    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  Rtjaumur,  we  have 
added  several  particulars  not  mentioned  by  him  f. 

In  order  to  preserve  some  specimens  of  the  gypsey- 
molh,  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 


•  female  pynsey  moth,  one-third  the  natural  size,  just  finish- 
ing her  group  of  i-ggs.  b,  female  gypsey  moth,  with  its  bodv 
covered  with  down,  c,  circle  of  eggs  covered  with  hair,  and  d, 
conical  mound  of  eggs  covered  with  hair,  laid  by  gypsey-motha 
in  contincment. 


;.  R. 


|-  Reaumur,  Mem.  ii.,  101 
F  5 


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 
circumstances  as  to  space,  instead  of  forming- a  wheel, 
piled  up  her  eggs  in  form  of  a  circular  mound  ;  but  as 
the  number  of  her  esgs  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,  how- 
ever, the  regular  slope  and  tiling  of  the  down  was 
carefully  preserved*  We  have  now  (April,  1S30)  a 
numerous  brood  of  caterpillars  from  these  very  eggs. 

The  eggs,  \yhich  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  comes  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  tlie  escape  of  the  heat  generated  there.  The 
feeling  of  cold,  therefore,  does  not,  as  might  be  suj)- 
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  fiom  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,  hovvever,  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  plac«  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  ai/rijlua,  and  P.  Chry- 
sorrhma,  Stephens),  whose  caterpillars  spin  them- 
selves a  warm  nest  before  the  setting-in  of  the  wint«^ 
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  th«» 
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  perform!  112;  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 
instrument  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  Lu9on,  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. — Me- 
moires  sur  ks  Anim.  suns  Vtrtcb. 


SPIRAL   poRM    OF    EGGS.  85 

These  egg's  were  extremely  small,  and  the  down  very 
fine,  like  the  short  fur  of  the  beaver,  and  of  a  pretty 
squirrel-grey  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 
respect  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  eg^  is  somewhat  of  the  form  of  a  funnel-shaped 
wine-glass — broader  at  top  than  at  bottomf;  and  it 

*  Reaumur,  Mem.  ii.  107. 
1  See  two   of  these  eggs  figured  iti    *  Insect  Architecture/ 
p.  19. 


86  INSECT   TRANSFORMATtONS. 

is  worthy  of  remark,  that  this  is  the  precise  form  of 
tlie  arch-stones  of  a  bridge.  They  are,  in  fact,  built 
tog-ether  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  heaviest 
rain  dashes  upon  the  eggs  without  injury. 


Eggs  of  thelackcy-motb,   wound  spirally  round   a  twig  of  haw- 
thorn ;  natural  size,  and  magnified. 

It  may  be  a  question  with  some,  when  they  com- 
pare these  naked  eggs  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.  Pro])ably  also,  this  may  be  con- 
nected with  their  electrical  state  ;  and  that  has  always 


HYBERNATION   OF    EGGS.  87 

an  intimate  connection  with  heat  in  aninnated  bodies. 
The  hving  principle,  to  which  we  shall  by  and  bye 
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  ac-cidents, 
than  in  a  more  advanced  stage  of  existence  ;  and  it  is 
most  probable  that  the  greater  number  remain  un- 
hatched  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  {Aphu  Alni,  and 
A.  Pruni)  covered  each  egg  individually  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  number  of  this  family  lay 
their  eggs  in  an  exposed  situation,  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  disco- 
vered (Jan.  1830)  a  numerous  deposit  of  the  eggs  of 
the  magpie  plant-louse  {Aphis  Samhuci)  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  irregular  patch  upon 
a  part  of  the  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  les  Insecles,  iii.  48,  51.  t  J.  H. 


88  INSECT  TRANSFORMATIONS. 

remarkable  manner.  The  mother  deposits  her  eg:ij;8 
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, 
— whencethey  were  termed  Gall  Insects  hy  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  cochinelle  {Coccus  Cactiy 
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 ; 


Magiiiried  cocln'i 


111  eels,  iCuccus  cacti),    a,  Male,  h,  Female. 


90  INSECT    TRANSFORMATIONS. 

l)!it  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  acciden- 
tally 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  Re'aumur,  in  the  larva  state, 
though  we  have  frequently  searched  for  these  larvae 
in  vain  during  winter,  on  vines  where  they  swarmed 
in  myiiads  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  otf-goings 
of  the  branchlets  in  an  oval  form,  like  that  of  a 
minute  wood-louse  {Oniscus),  of  a  silvery  grey 
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,  thotigh  there  is  mixed 
up  with  the  eggs  a  small  quantity  of  a  greyish  white 
powder,  which,  we  are  inclined  to  conjecture,  may 
be  the  dried  remains  of  it;  and,  the  more  so,  that 
Ueaunmr  figures  the  gossamer  as  abundant  in  the 
coccus  of  the  hawtln)rn.  Unfortunately  he  lias  not 
*  Si.  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  b  c.  Eggs  of  the  hawthorn  coccus,  covered  by  the  body  of  the 
deiid  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  Kirby,  "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  t."  From  the  manner  in 
which  this  justly  popular  author  speaks,  it  would  ap- 
pear he  had  not  elsewhere  met  with  this  coccus  ;  but 
♦   I.  R.  t  Intr.  i.  VJ7. 


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  Cuciirbitaria  Berberidisy 
Grev.,  or  Cryptosph(eria  Pteridis,  Sowerb.),  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  iiiclined  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.  Rt^aumur  put  the 
matter  beyond  dispute  by  actually  hatching  ihe 
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  cmidatus),  and  the  gold  crested  wren  {Regu- 
*  J.  R. 


DEPOSITIONS   OF    EGGS.  93 

lus  crislatus,  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 
Reaumur  endeavoured  to  bring  into  use  as  a  substitute 
for  silk;  but  he  was  unsuccessful  in  procuring  it  in 
quantity,  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  silken  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  w  ater. 

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  g'rass  *; 
and  we  once  found  a  large  one  of  an  elongated 
shape,  and  composed  of  very  white  silk,  on  a  spike  of 
grass  at  Compton-Basset,  VViltshiref. 


Spiders'  nests. 

The  vapoiirer  {Orgyia antiqua,  Ochsenh.),  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 
instances  of  it  as  to  reject  the  explanation.  Swam- 
merdam  also  observes,  that  "  this  custom  of  fastening 
the  eggs  to  the  web  is  a  constant  method,  and 
by  the  immutable  law  of  nature,  is  so  peculiar 
to  this  species  of  insects,  that  I  have  never  ob- 
served it  in  any  other  kind  whatsoever.  This 
female,"  he  subjoins,  "  like  a  most  prudent  house- 
wife, never  leaves  her  habitation,  but  is  always 
fixing  her  egg^  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.  f  J.  R. 

X  Swammerdaui>  ;it.  ii.  p;ige  7. 


DEPOSITIONS    OF   EGGS. 


95 


reason  for  this  is,  that  the  female  of  this  motii 
havini^  only  the  rudiments  of  vving-s,  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  eg-gs  warm  during  winter  ;  for  though  they 
are  placed  on  the  outside  of  the  web,  the  whole  is 
usually  under  some  projection  of  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. 


"^'ii^M^-' 


Vapourer-moth  {Orgym  antiqua'),  male  and  female,  the  latter 
without  wings;  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 
Spallanzani  and  John  Hunter,  by  exposing  several 
species  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, 
'•  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  exposeil 
to   its    iniluenre-   in    the  open  fields,  on  the  naked 


96  INSECT   TRANSFORMATIONS. 

earth,  or  on  the  branches  of  trees?  Yet,  when  llie 
spring  had  tempered  the  air,  these  eg:g's  produced  as 
they  usually  did  after  the  mildest  vvinters.  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  eij^gs  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  inclosed  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  AmmonkOy  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  toanimalcula 
and  insects.  Germs  in  general  can  support  2° 
below  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-worm  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  cam 
be  resisted  by  their  eggs.  What  can  be  the  cause  ofl 
sc  great  a  difference?     Insects  killed  at  lG°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 
constituent  spirituous  or  oleaginous  parts,  or  from 
some  principle  adapted  to  abate  the  power  of  cold  *. 
If  eggs  do  not  freeze,  it  is  probable  the  included 
embryos  do  not  freeze.  Is  there  anything  won- 
derful, 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,  concentrated  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  1  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  th(*  freezing  point,  the  eggs  of  other 
animals  may  be  hatched?  Nor  should  it  surprise  me 
to  be  tcld  of  animals  whose  eggs  would  produce  at 
much  greater  cold,  after  knowing  that  there  are  plants, 
beings   so   similar   to    animals,  and   many  of  Ihem, 

*  In  plain  language,  Spallanzani  did  nut  know  what  to  make  ol 
the  facis. 

G 


9S  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  f- 

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  nnich 
greater  number  of  insects,  even  of  the  smaller  and 
more  delicate  kinds  {Akyrodcs,  Corethra,  Ahicita^ 
&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  larva?  of  some  small 
tipula  (Boletophila?),  which  we  found  in  abundance 
in  Birch  Wood,  Kent,  feeding  on  a  fungus  {Bohtua 
JhnicntarmSj  P'ries),  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 

*  Spallarizani's  Tracts,  transl.  by  Dalyell,  v()I.  i.  p.  o3. 
f  Hunter  on  the  Anima!  Economy. 


EFFECTS   OF    COLD    UPON   INSECTS.  99 

migratory  birds  seem  to  have  been  aware  of  tliis 
abundance  of  insects  by  tlieir  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  be- 
fore their  average  time  *. 

*J.  R. 


100 


Chapter  V. 

Hatcliing  of  Insect  Eggs 

The  contents  of  an  egg  principally  consist  of  nutri- 
ment adapted  to  the  different  parts  of  the  germ 
which  it  contains — the  yolk  for  nourishing;  the  soft 
parts;  tiie  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  j-osition  for  par- 
taking of  the  repast, — namely,  in  a  particular  corner 
where  it  may  breathe  fresh  air  always  communicated 
to  the  chamber  of  the  egg  by  ventilatory  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  Malpighi 
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  u  ith  the  surface 
by  the  mobility  of  the  slings  and  the  weight  of  the 
oil-vessel  tending  downwards,  however  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   yolk,  of 

*  M;ilpi<;lii,  (ie(Uo  iiicuUato;  Lceuweiihoeck,  Epist.  phys.  xl. ; 
a«)d  Hiuvey,  in  Willughhy's  Ornilliol.  c.  ill. 


HATCHING   OF    EGGS.  101 

course  the  more  weighty  part  always  descends,  in 
every  position  of  the  egg,  as  far  as  they  uill  permit, 
and  the  chick  being  thence  prevented  from  sliding 
down,  nourishes  itself  in  security. 

We  cannot,  on  account  of  their  minuteness,  ascer- 
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 
embryo  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  indispensably  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  increase  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  numerous  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. 
I  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 
Ithen  generally  cease  to  feed,  they  cannot  possibly  live 
i  long.     A  few  instances,  however,  have  been  observed, 
of  insects  performing  something  very  similar  to  the 

g3 


102  INSECT   TRANSFORMATIONS. 

incubation  of  birds,  though  we  have  the  hig^i  authority 
of  Fabricius,  that  "  insects  never  sit  upon  their  eggs*." 
Upon  the  incontestable  statements  of  two  dis- 
tinguished observers  of  insects,  Frisch  f  and  De 
Geer,  the  female  of  the  common  earwig  (Forjicula 
aunci/laria,  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  disco- 
vered a  female  earwig  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,  in  collecting  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  |. 
At  another  time,  in  the  beginning  of  June,  De 
Geer  found  under  a  stone  a  female  earwig  accompa- 
nied with  a  numerous  brood  of  young,  to  all  appear- 
ance newly  hatched,  and  nestling  under  their  mother 
like  chickens  under  a  hen.  These  he  likewise  placed 
in  a  nurse-box  with  fresh  earth;  but  instead  of  burrow- 
ing into  the  mould,  as  he  had  expected,  they  crowded 
under  the  bosom  and  between  the  legs  of  their  mo- 
ther,  who  remained  quiet  and  evidently  pleased,  suf- 
fering 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  ix\)^)\e  ;  and  perceived  that 

*  Fabricius,  Philosoph.  Erilomol.  Ixxvi. 
t  liisecten  in  Deutschland,  4to.  1766. 
I  De  Geer,  Mem.,  vol.  iii.  p.  518. 


HATCHING    OK    EGGS.  103 

tt>€y  grew  from  day  to  day,  and  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  dis- 
liking exposure  to  the  light,  they  may,  by  chance, 
attempt  to  take  shelter  in  the  ear,  the  disagreeable 
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  '  •'*  no  real 
injury. 


Drum  of  the  ear,  shovving  that  there  is  no  passage  through  it  to 
the  brain. 

Kirby  and  Spence  are  inclined  to  infer  that  a  tree- 
bug  {Acanthosoma  grlsca,  Stephens)  may  also  sit 
♦  J.  R. 


104  INSECT    TRANSFORMATIONS. 

upon  its  eg'g's*,  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 arotmd  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  beat- 
ing her  wings  rapidly  and  incessantly,  and  never 
stirred  from  her  young.  But  even  all  this,  affection- 
ately maternal  as  it  must  be  considered,  is  far  from 
authorizing  the  conclusion  that  she  sits  upon  her 
eggs  ;  thong-h  it  is  certain  she  must  remain  near  them 
till  they  are  hatched,  unless  she  belong  to  those  men- 
tioned by  Busch  as  ovo-viviparous  f. 

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 
eg-gs.  Many  of  these  mothers,  however,  die  before 
their  young  are  hatched, — all  of  them,  perhaps,  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  litlle  more  than  an  average  decree  of 
coldness,  every  one  of  them  died,  some  living  a 
longer  time,  and  others  a  shorter  |.  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  celebrated  Har- 
vey §.     "  In  order,"  says  Swammerdam,  *'  to  hatch 

*  Intro,  i.358,  and  iii.  101, 

I  Schneider,  Europiiische  Schmctterlinge,  i.  206.         ;*  J.  R. 

§  Harvey,  De  Generatioiie. 


HATCHING    OF    EGGS.  105 

her  eggs  tlie  better,  she  carries  them  about  as  it  were 
in  a  case,  with  wonderful  solicitude  and  affection; 
insomuch,  that  when  the  skin  forniin<^  this  case,  which 
hangs  to  the  hinder  part  of  lier  body,  is  by  any  acci- 
dent broken  off,  the  Httle  insect  seeks  after  it  with  as 
much  earnestness  and  industry  as  a  iien  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  this  spider,  which,  though  no  less  fierce 
and  ferocious  in   aspect  than  her  congeners,   mani- 
fests an  extraordinary  change  of  mien  when  forcibly 
deprived  of  her  eggs.      Then  she  instantly  appears 
I  tame,  stops  to  look  around  her,  and  begins  to  walk  at 
I  a  slow  pace,   and  search  on  every  side  for  what  she 
[  has   lost,   nor  will  she   even  fly  when  one  threatens 
i  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  undisturbed,  will  leisurely  attach  it  again 
j  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  pitfall  of  an  ant-lion 
{My rmelion  formicariuiri)'\ .  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*  struggled  hard  to  defeat  the  aim  of  the 
concealed  depredator;  but  the  gum  which  fastened 
her  bag,  not  being  calculated  to  withstand  such 
violence,   at  length  gave  way,  and   the  ant-lion   was 

*  Book  of  Nadiro,  j)t.  i.  p.  24. 
<■  See  Insect  Archittclu'Cj  p.  209. 


106  INSECT   TRANSFORMATIONS. 

about  to  carry  off  the  prize  in  triumph.  The  spider, 
however,  instantly  re^iained  it  with  her  mandibles, 
and  redoubled  her  endeavours  to  snatch  the  bag  from 
her  enemy  ;  but  her  efforts  were  vain,  tor  the  ant-lion, 
being  the  stronger,  succeeded  in  dragging-  it  under 
the  sand.  The  unfortunate  mother,  now  robbed  of 
her  eggs,  might  have  at  least  saved  her  own  life,  as 
she  could  easily  have  escaped  out  of  the  pitfall  ;  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,  deprived  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  i)ortion  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  Geert; 
*'  without  which,"  say  Kirby  and  Spence,  "  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,  CEuvrcs,  vol.  ii.  p.  435. 
t  Do  Geer,  Mem.  vol.vii.  p.  11)4.  X  Iiitrod.  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  b^en 
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  not  beat 
her  away  from  it  after  it  was  detached.  "  By  and 
bye,"  he  continues,  ''  I  observed  with  surprise  that 
she  iiad  abandoned  and  kept  aloof  from  the  very  bag 
which  she  had  previously  defended  with  so  much 
courage  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  luing  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  PiOt  abandon  for  some 
time,  and  for  the  purpose,  as  I  was  half  inclined  (par- 
don 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, 
whicii  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 
*  J.  R.  t  Bonnet,  (Euvres,  vol.  ii.  p.  440, 


108  INSECT   TRANSFORMATIONS. 

the  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  remov- 
ing the  stranger,  however,  she  showed  the  same  indif- 
ference 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  batching  eggs 
occurs  in  several  insects,  thence  termed  ovo-vivipa- 
rous,  which  retain  the  eggs  within  their  bodies  till 
they  are  hatched ;  and  in  this  way  they  appear,  like 
larger  animals,  to  produce  young  instead  of  eggs.  We 
do  not  here  allude  to  the  cochenille  insects  formerly 
mentioned ;  for  though  these  cover  their  eggs  with 
their  bodies,  it  is  after  they  are  laid  and  imbedded  in 
gossamer.  Neither  can  these  singular  insects  be 
properly  said  to  sit  upon  their  eggs,  inasmuch  as  the 
mother  always  dies  when  she  has  finished  laying. 

Tlie  guffer  (Blennius  ovo-viviparus,  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  fartlier  out  to  sea,  that  they  may  be  out  of  the 
reach  of  thtir  natural  enemiesf.  Ourcommon  viper 
{Coluber  bents,  Linn.)  is  also  ovo-viviparous,  as  are 
several  other  reptiles;  though  it  is  an  exception  to 
the  general  rules  in  this  class.  We  caught  a  female 
of  the  nimble  lizard  (JLacerta  agilis,  Linn.)  on  a  heath 
near  Sorn,  Ayr>hire,  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  li 

♦  J.  R.  f  Lacepede,  Poissons,  ii.  p,  497.  J  J.  R. 


I 


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  tlience 
led  to  put  the  question,  whether  such  flies,  under  dif- 
ferent circumstances  of  temperature,  do  not  sometimes 
produce  young,  and  at  other  times  deposit  eggsf. 
He  might  as  well,  says  Reaumur,  have  asked  whe- 
ther, in  certain  circumstances,  a  hen,  instead  of  laying- 
eggs,  should  bring  forth  chickens.  The  fact,  on  the 
contrary,  has  been  ascertained  by  Reaumur,  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  similar  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  Ccssar,  I^inn.),  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, 
f  Redi,  Esperienze  intorno  alia  Gen.  degl'  Insetii,  4lr«.  1668. 
%  Annales  des  Science?  N;itiirclk'«.  o    Pa<:f»  3. 


110 


INSECT  TRANSFORMATIONS. 


blue-bottle,  rather  longer  and  more  slender,  and  black, 
with  lig'hter  stripes  on  the  shoulders,  is  not  blue  in  the 
ubdomen,  but  greyish  black,  and  all  over  chequered 
with  squares  of  a  lig-hter  colour.  This  chequered  blow- 
fly {Sarcophaga  carnaria,  Meigen)  does  not  even 
belono-  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  ofFensiveparts  of  carcasses. 
The  arrangement  of  the  numerous  minute  larvse  iu 
the  pouch  is  very  remarkable,  and  resembles  the  coil 
of  a  watch-spring,  or  a  roll  of  ribbon.  Reaumur 
had  the  patience  and  perseverance  to  uncoil  this  mul- 
titudinous 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- 


A,  tlie  chequered  blow-fly.     B,  the  abdomen  of  the  chequered 
>low-fly,  opened  and  nja^nified,  showing  the  coil  of  young  larvae. 


C,  the  coil  of  lu'vx  partly  unwound 


OVO-VIVIPAROUS    INSECTS. 


Ill 


third  of  an  inch,  and  he  computed  that  there  were 
about  20,000  young  in  the  coil*.  When  this  extra- 
ordinary fecundity  is  considered,  we  need  not  wonder 
at  the  countless  swarms  which  appear  as  if  by  magic 
upon  a  joint  of  meat  during  hot  weather. 

Like  most  female  insects,  the  mother-fly  dies  in  a 
few  days  after  giving  birth  to  her  numerous  brood ; 
but,  iHilike  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,  Reaumur  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  larvse,  and  closed  the  natural  opening 
of  the  pouch  with  sealing-wax,  so  that  it  was  impos- 
sible 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  slmt  up  for  ten  days. 

Another  large  grey  fly  with  brick-red  eyes  (species 

A  B 


A,  large  grey  blow-fly,  with  the  abdomen  opened,  showing  the 
young  maggots.  B,  breathing  apparatus  of  the  maggot  of  a 
large  grey  blow-fly. 

*  Reaumur,  Mem.  iv.  417. 

H  2 


112  INSECT   TRANSFORMATIONS. 

not  ascertained)  was  discovered  by  Reanmur  to  be 
ovo-viviparons ;  but  the  embryo  flies  were  not  ar- 
ranged 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  apparatus,  which,  when  shut,  as  it  could 
be  at  pleasure,  appeared  in  the  form  of  a  crown. 

Amongst  several  other  ovo-viviparous  flies  dis- 
covered by  Reaumur,  there  was  a  very  minute  tipu- 
lidan-gnat  (species  not  ascertained)  with  a  jet-black 
body,  white  wings,  and  beaded  antennae,  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  circumstance,  that  "  the  minute 
and  the  grand  are  nothing,  or  rather  are  the  same, 
to  the  Author  of  Nature." 

The  numerous  genus  Ajjhis  presents  the  singular 
anomaly  of  producing  eggs  in  the  autumn  and  liv- 
ing young  during  sumn.er,  and,  as  Curtis  tells  us, 
even  during  winter  in  green-houses.  De  Geer,  how- 
ever, 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  ascertained  the  curious  fact,  that  in  three  montiis 
nine  generations  of  these  insects  may  be  produced  in 
succession,  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  produced  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  Tnsectes,  iii.  70. 


EGGS  OF    APHIDES.  113 

Bonnet,  however,  whose  opinion  is  entitled  to  con- 
siderable authority,  seems  to  think  that  the  eg-gs  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  eg-g,  surrounded  by  food,  by  means  of  which  it 
is  developed  and  supported.  It  is  nothing  more,  he 
conjectures,  than  an  asylum  of  which  the  aphides 
appearing  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 
mothers  are  not  then  truly  oviparous,  even  in  autunm, 
when  they  deposit  these  pseudoeggs;  since  their 
young  are  almost  as  perfect  as  they  ever  will  be,  in 
the  asylum  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- 
quence, 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  Febru- 
ary, and  in  1830  we  had  a  brood  of  several  hundreds 
produced  of  the  oak  aphis  {Aphis  Quercu.s)  *. 

The  failure  on  the  jjart  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 
Ruber's  own  words. 

"  One  day  in  November,"  says  he,  "  anxious  to 

know  if  the   yellow  ants   {Formica  Jiarci)   began  to 

bury  themselves   in    their  subterranean   chambers,  I 

destroyed,  with  care,  one  of  iheir  habitations,  story  by 

*  J.  R. 


114  INSECT    TRANSFORMATIONS. 

story.  I  had  not  advanced  far  in  this  attempt,  when 
I  discovered  an  apartment  containing  an  assemblage 
of  httle  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  dwelling 
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  ditferent  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,  greyisli, 
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  them  highly;  after  having  visited  them, 
they  placed  one  part  in  the  earth,  but  I  witnessed  the 
attention  they  bestowed  upon  the  rest;  they  ap- 
proached them,  slightly  separating  their  mandibles  ; 
passed  their  tongue  between  each,  extended  them,then 
walked  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  affiictionate  regard,  conveyed  them  with  extreme 
tenderness  to  the  Uttle  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  with  the  origin  of  those  of 
which  I  have  just  spoken,  and  by  chance  discovered 
they  contained  little  aphides;  but  it  was  not  these 
individual  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- 
liill,  I  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.  1  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  thempelves  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  E. 
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  eggs  they  lie  in  multi- 
tudes, "  I  suppose,''  says  Derham,  "  by  way  of  in- 
cubation-j-.'*  '^  I  have  observed,"  adds  Sir  E.  King, 
"  in  summer,  that  in  the  morning  they  bring  up  those 
of  their  young  called  ant-eggs  {cocoo7is)  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- 
poboscidcB,  Leach)  resemble  the  aphides  in  some 
points  of  their  economy,  though  in  others  they  are 
singularly  peculiar.  Reaumur  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. Reaumur  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.   lllh  ed. 
J  Pliil,  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 
afterwards  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  parents.  He  calls  them  spider-flies,  from  their 
resemblance  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  (^Hippohoscidce,  I.eaoh). 

We  have  the  more  willingly  introduced  this  sub- 
ject here,  that  another  fly  {Craterina  Hirundinis, 
Olfers),  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  Reaumur,  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  existence,  lives  by  sucking  the  blood  of  the  swal- 
lows, as  the  one  first  mentioned  sucks  the  blood  of 
horses,  horned  cattle,  and,  it  is  also  said,  of  man. 

h5 


118  INSECT   TRANSFORMATIONS. 

The  effect  of  heat  upon  the  eggs  of  insects  has  been 
carried  much  farther  than  in  the  experiments  just 
alhided  to  of  Reaumur  and  Bonnet*.  Spallanzaiii  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  j)olychloros  ?)  perfectly 
corresponded  with  those  of  the  silk-worm.  In  the  case 
of  the  eggs  of  the  blow-fly  (^Musca  vomitoria)  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  pupee  were  produc- 
tive at  104°  and  106°,  but  not  at  llPf- 

If  these  experiments  may,  as  we  believe  they  may, 
be  relied  on,  we  have  some  reason  to  doubt  that  "  the 
eggs  of  the  inusca  vomitoria^  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  steaks,  in 
a  heat  not  merely  of  212°,  but  of  three  or  four  times 
212°;  and  yet,  instead  of  being  hereby  destroyed,  we 

*  See  Insect  Architecture,  p.  24. 
t  Spallanzani,  Tracts  by  DalyelJ,  vol.  i.  p.  35. 


EFFECTS  OF  HEAT  UPON  EGGS.       119 

sometimes  find  them  quickened  by  this  very  exposure 
into  their  larva  or  grub  state*."  It  woiild  have  been 
well  if  some  more  accurate  authority  liad  been  given  for 
so  miraculous  a  fact  than  this  general  statement ;  the 
appearance  of  mag-g-ots  on  broiled  meat,  from  which  the 
inference  is  apparently  made,  seems  rather  to  indicate 
that  eggs,  or  more  probably  ovo-viviparous  larvse,  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  G^<y 
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  inju- 
ries with  more  impunity  than  when  very  vivacious. 
We  once  saw  a  very  delicate  young  girl,  emaciated 
with  scrofula,  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  (o 
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,  and  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 i". 

*  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  manag'ementoftheeg^p^s  of  the  silk- 
worm Count  Dandolo  directs  the  temperature  of  the 
stove-room  to  be  64°  when  they  are  first  put  in. 
"  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  tempe- 
rature of  the  stove-room  is  raised  to  75°,  it  is  advan- 
tageous 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  dry- 
ness which  might  occur  in  the  stove- house,  particu- 
larly during  a  northerly  wind  :  very  dry  air  is  not 
favourable  to  the  development  of  the  silk-worm*." 
Damp  ov  stagnant  aic,  or  sudden  changes  of  tempera- 
ture, either  high  or  low,  are  exceedingly  injurious  to 
the  hatching  of  eggs. 

From  some  very  curious  experiments  of  Miche- 
lotti,  it  appears  that  exposure  to  light  is  by  no  means 
favourable  to  the  hatching  of  eggs.  This  ingenious 
naturalist  inclosed  a  number  of  eggs  in  glass  vessels, 
admitting  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  experiments  upon  vegetable  seeds  t-  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  |. 

Among  the  singular  circumstances  in  which  insects 
dilfer  from  the  larger  animals,  we  may  reckon  that 

*  Count  Dandolo  on  Silk-Worms,  Eng.  trans.,  p.  55. 
I  Philosophical  Mag.  vol.  ix.  p.  244.         J  Introduc.  iii.  p.  77, 


[NCREASE   IN    SIZE    OP   EGGS, 


121 


of  the  eg'gs  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  (TenthredinidcB,  Leach)*.  Other 
instances  were  subsequently  discovered  by  Reau- 
mur, De  Geer,  Derham,  Rosel,  and  the  younger 
Huber.  "It  ought  not,"  says  Rdaumur,  speaking  of 
gall-flies  (Cy?iipid{B,  Westwood),  "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 
species  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  from  the  mother  flies  which  I  killed  were 


Generation  of  a  water-mite  {^HydracTina  abstcrgens). 
a  a,  the  water-scorpion,  in  whose  body  the  mite  fixes  her  eggs. 
hb,a  magnified  view  of  one  of  its  claws,  c,  a  tooth-lilse  process 
for  restraining:  the  motion  of  the  joint,  d,  the  water-mite,  c,  a 
greatly  magnified  view  of  one  of  its  eggs.  /,  the  hook  by  which 
It  is  inserted  into  the  body  of  the  scorpion. 


*See  Insect  Architecture,  pp.  157-8. 


122  INSECT   TRANSFORMATIONS. 

remarkably  small;  and  I  thence  inferred  that  the  en-ir 
would  have,  and  indeed  had,  increased  in  the  gall''." 

Rosel  made  a  similar  observation  on  the  red  eg-gs 
of  a  water-mite  (Hydrachiia  abstergens) ;  and  he  was 
induced  to  suppose  (justly,  as  we  think)  that,  as  they 
are  deposited  upon  the  bodies  of  water-scorpions 
{Nepid(e,  Leach),  they  derive  their  means  of  in- 
crease from  themf.  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 
l>om  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  in- 
crease and  transparency  to  the  humidity  imparted  to 
them  by  the  vvorking  ants  who  so  assiduously  pass 
them  through  their  mouths.  "For,"  he  adds,  "if  they 
be  not  surrounded  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  development  of  the  included  grub  §.'' 

The  most  minute  observations,  however,  of  this 
khid,  which  have  hitherto  been  pubhshed,  were  made 

*  Reaumur,  Mem.  vol.  iil.  p.  479. 

tRtisel,  Insecten.  vol.  iii.  p.  152, 

%  Dc  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 
diadema),  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  experimenting 
on  the  eggs  of  birds.  The  germ,  or  cicatricula,  which 
is  composed  of  minute  granules,  when  placed  in  a 
due  temperature,  begins  to  expand  towards  the  extre- 
mity 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  molecules, 
producing  a  sort  of  translucent  cloud,  through  which 
the  globules  of  the  yolk  may  be  distinguished.  The 
place  which  the  germ  previously  occupied  appears 
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, 
tiie  outline  of  whose  head  and  body  becomes  appa- 
rent, occupying  a  little  more  than  a  fourth  of  the  egg. 
At  first  this  embryo  appears  homogenous,  but  by  and 
bye  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  closely 
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 
*   Hcroldtj  Kxercit.  de  Gener.  Aranearuin  in  Ovo. 


124 


INSECT   TRANSFORMATIONS. 


n-reat  deal  of  trouble,  by  alternately  stretching'  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 
enveloped  in  an  extremely  delicate  membrane,  which 
it  does  not  moult  unless  the  weather  is  favourable 
and  fine  f . 


Hatching  of  the  egg  of  (he  garden-spider  {Epeira  dtadema').  a, 
natural  size,  b,  egg  magnitied,  the  cicatricula  (a  white  spot)  in  the 
front.  C,  the  germ  enlarged ;  a,  the  head,  and  b,  the  body  of  the 
embryo,     d,  the  embryo  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|.  In 
the  experiments  made  by  us  upon  the  eggs  of  the  wolf- 
spider  (JLycosa  saccata),  we  more  than  once  kept  the 
young  in  boxes,  where  they  were  forgotten  and 
without  food  ;  and  we  uniformly  found  that  they  re- 
mained 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 
elusion,  may  be  seen  through  the  shell,  snugly  coi  ed 

*  De  Geer,  Mem.  vii.  p.  196.  i 

f  Diet.  Classique  d'Hist.  Nat.  xii.  141.  I 

X   Redi,  Esperienze,  99.  ^  J.  R.  j 


CONSTRUCTION    OF    EGGS. 


25 


up  in  a  ring,  as  is  distinctly  shown  in  many  of  the 
beautiful  and  accurate  figures  of  Sepp  *. 


a,  egg  of  the  privet  hawk-moth  (^Sphin.v  lAgustri)  magnified, 
showing  Jhe  inclosed  embryo,     b,  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  humanus),  and  with  the  bird-louse 
{Nirmus),  found  on  the  neck  feathers  of  the  golden 
pheasant.  A  still  more  ingenious  contrivance  was 
discovered  by  the  Rev.  R.  Sheppard,  in  the  egg  of  a 
field-bug  {Pentatoma,  Latr.),  which  is  not  onlyfur- 
*  Der  Woiidercn  Gods,  passim. 


126 


INSECT   TRANSFORMATIONS. 


Doors  in  egofs  for  the  escape  of  the  larvae, 
a,  egg  of  the  louse  {Pediculus  hurnanus).     b,  egg  of  the  penta- 
toma.     c,  shell  of  a  moth's  egg  found  upon  the  dew-berry — all  mag- 
nified. 

nished  with  a  convex  lid,  but  with  a  lever  of  a  horny 
texture,  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  (^Rubus  ccesius)  we  found  a 
beautifully  ribbed  egg  of  some  moth,  which,  having 
been  brought  into  our  study,  in  January,  1830,  was 
hatched  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  hatched 
after  deposition  depends  mainly  upon  temperature; 
for  by  keeping  them  in  an  ice-house  in  summer,  the 
hatching  maybe  retarded  t,  as  it  may  be  hastened 
(witness  the  instance  in  the  preceding  paragraph)  by 
heat  in  winter;  but  there  are  many  other  circum- 
stances unknown  to  us  which  often  hasten  or  retard 
the  process.  The  eggs  of  the  blow-fly  {Muscavomi- 
torid)  are  said  to  hatch  within  two  hours  |,  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  re- 

*  Kirby  and  Spencc,  iii.  104.  f   Reaumur,  Mem. 

t  Nouv.  Diet.  d'Hist.  Nat.  xii.  564. 


PERIODS    OF    HATCHING.  127 

mark,  however,  that,  the  periods  of  hatching  corre- 
sjDond  ill  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  example  of  this 
in  the  spring  of  1829.  A  lackey-moth  had  deposited 
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,  se- 
veral 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  cir- 
cumstance 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  airf. 

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  rinula),  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  differ- 
ence of  hatching  could  not  have  arisen  from  difference 
of  weather,  exposure,  &c.  I"  In  the  case  of  the 
lackeys  on  the  sweet-briar  above  mentioned,  some 
were  hatched  several  days  before  others,  but  whether 
these  were  of  ditferent  sexes  we  did  not  ascertain. 
*  J.  R.  f   Kirby  and  Spence,  bitr.  ii.  434. 

X  J.  Rcnnie,in  Mag.  of  Nat,  Hist.  vol.  i.  p.  373. 


128 


SECTION  IL— LARViE* 
Chapter  VI. 

Structure  of  Caterpillars,  Grubs,  and  Maggots, 

It  is  reported  by  Boerhaave,  in  his  life  of  Swamrp^r- 
dam,  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 
Swammerdani,  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  tliis  and  other  wonders  of  the  insect  world,  dis- 
closed to  him  by  the  great  naturalist,  that  he  made 
him  a  princely  otTer  to  induce  him  to  reside  at  his 
court;  but  Swammerdam,  from  feelings  of  indepen- 
dence, modestly  declined  to  accept  it,  preferring  to 
continue  his  delightful  studies  at  home,  'i'he  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  larva ;  and  in  popular  lan- 
guage, ^.cattrpiUar,  or  grub,  if  furnished  with  feet,  and  Amaggotf 
wonn,  or  (pintle,   ii  without  feet. 


ANIMAL    AND    VEGETABLE    TRANSMUTATIONS.  129 

been  recently  started  by  continental  naturalists,  who 
maintain  that  vegetables  are  actually  converted  into 
animals,  and  these  ag-ain  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  transmutation 
of  lead  and  other  inferior  metals  into  gold  and  silver  ; 
which  doctrine  was,  indeed,  supported  upon  the  sup- 
posed fact  of  insects  being  thus  transmuted  *.  But  vi- 
sionary as  either  of  these  may  appear,  they  have  both 
been  supported  by  men  of  talent  and  distinguished 
reputation.  It  does  not,  perhaps,  at  first  sight  seem 
more  impossible,  that  water  should  be  transmuted  into 
diamonds,  or  brass  into  gold,  than  thutan  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  rigidly  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  contrary 
to  all  experience,  and  to  the  best  experiments.  We 
say  the  6e.s^ ;  because  observations,  if  not  experiments, 
have  been  made  for  the  express  purpose  of  proving 
such  improbable  transmutations. 

'*  I  have  shown  to  a  great  number  of  persons," 
says  Professor  Agardh,  "the  changeable  crow  silk 
{Conferva  mutahilis.  Roth  ;  Draparjialdia  in. 
BoRY  St.  V.)  in  its  state  of  a  plant,  the  3d  of  August, 
change  by  the  5th  into  molecules  endowed  with  loco- 
mobility,  reunite  by  the  6th  into  simple  articulations, 
and  reconstituted  by  the  10th  into  the  primitive  form 
of  the  plant  t-"  Previous  to  this  (in  1814)  Professor 
Nees  von  Esenbeck,  of  Bonn,  published  similar  obiser- 

*  Sir  Theodore  Mayerne,  Epist.  Dedicat  ad  Theatrum  Insect. 
MouffetU. 

f  Agardh,  Diss,  de  Melamorph.  Al^arum.  1820 


130  INSECT   TRANSFORMATIONS. 

vations,  in  which  he  remarks,  that  '*  as  the  phenomena 
in  question  appear  to  contradict  certain  principles 
admitted  into  the  reigning  systems,  we  often  prefer 
rather  to  deny  the  conclusions  of  candid  and  ex- 
perienced observers  than  to  receive  what  has  hitherto 
been  regarded  as  untenable  by  generally  admitted  au- 
thority. In  this  situation  are  placet!  all  observations 
upon  the  transition  or  metamorphosis  of  vegetable  life 
(characterized  by  immobility)  into  animal  life  (cha- 
racterized 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  em- 
bryo developes  itself  into  a  motionless  vegetable*." 
Agardh,  in  his  account  of  another  allied  family 
{Ocillatorice),  has  even  given  figures,  first  of  the 
plant,  and  then  of  the  animalcules  into  which  its 
filaments  are  converted  f,  which  induced  Bory  St. 
Vincent  to  remark  sarcastically,  that  '*  all  nature 
appears,  to  the  Professor  of  Lund,  to  be  nothing  but 
confervse  travestied.  |'' 

Passing  over  what  has  been  published  on  this 
strange  doctrine  by  Vaucher,  Girod-Chantrans, 
Treviranus,  Cams,  and  others,  we  shall  only  stop  to 
mention  the  more  recent  observations  of  Francis 
Unger.  The  plant  he  selected  was  the  Conferva 
dilatata  /3  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  my  own  eyes  §." 
Like  Agardh,  he  has  given  figures  of  these  miracu- 

*  Quoted  in  '  Annales  des  Sciences  Naturelles'  for  1828. 
f  Agardh,  Icones  A)g.  ined.  i.  10. 
I  Diet.  Classique  d'Hist.  Nat.,  x.  469. 
^  Annales  des  Sciences  Nat ,  1828. 


ANIMAL  AND  VEGETABLE  TRANSMUTATIONS.    13! 

lous  changes,  which  our  readers  may  be  curious  to 
see. 


Supposed  animal  and  vegetable  metamorphoses. 

Since  the  only  proof  of  these  plants  being  trans- 
muted (as  is  alleg-ed)  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, 
*'  astonish  the  world  with  the  discovery  of  a  fig- 
tree  transmuted  into  a  mulherry-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 
observers*." 

It  is  apparently  a  branch  of  the  same  untenable 
theory  which  maintains  that  the  fluid  termed  by 
Heroldt  the  hlood  of  caterpillars  is  the  only  original 
portion  of  them,  which,  being  endowed  with  a  forma- 
tive power  t,  pro(hices  an  envelope  for  itself  of  mucous 
net-work  (rete  mucosu7ii),  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  remark, 
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.  "  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 

*  Dict.Class.d'Hist.  Nat.  X.  468. 

t  The  German  term  is  "  Bildende  Kraft,"  i.  e.   Fis  format rix, 
or  Nisus  formal ivus. 

I  Heroldt,  quoted  by  Kirby  and  Spence,  iii.  83. 
§  Quoted  by  Kirby  and  Spence. 


EMBRYO    BUTTERFLIES. 


133 


recorded  many  instances,  besides  the  one  under  con- 
sideration, of  their  strange  mistakes  in  o-uessing  at 
what  they  cannot  fathom.  We  prefer  followino- 
Swammerdam,  Rtjaumnr,  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  "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-bntterfty  (Pontia  hrarM:<s)y  magn'rfied, 

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  grey, 
spotted  with  black  ;  and  the  whole  surface  sprinkled 
with  thin,  short,  whitish  hairs*. 

"  In  order,"  continues  Swammerdam,  "  to  dissever 
plainly  that  a  butterfly  is  inclosed  and  hidden  in  the 
skin  of  this  caterpillar,  the  following  operation  must 

*  Ray,  Cat.  Cantab.,  quoted  by  Swammerdam.  See  fig.  a, 
page  62. 


134  INSECT   TRANSFORMATIONS. 

be  used.  One  must  kill  a  full-grown  caterpillar,  tien 
thread  toits  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 
wherewitli  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  contained 
and  folded  up  in  it.  This  done,  it  is  clearly  and  dis- 
tinctly 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. 

"  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.  20. 


EMKRYO   BUTTRRFLIES. 


135 


Kmbryo  butterflies  QPontice  Brassiccb),  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  Reaumur  made  a  similar  disco- 
very in  the  caterpillar  of  the  gypsey-moth  {Hyjjo- 
^yimia  dispar)  f. 


Female  of  the  perfect  cabbage-butterfly  {Pontia  brassicce'). 

In  order  to  harden  the  parts  of  the  incipient  butterfly 
that  are  soft,  Svvammerdam  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  Bomhyce,  29.  f  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 
analogy  to  the  embryo  of  a  plant  in  the  seed,  or  the 


a,  greatly  niagnified  view  of  a  section  of  the  bud  of  the  labur- 
luiiii.  It  exhibits  the  nascent  flowers,  arranged  in  regular  order, 
previou>ly  to  their  bursting  into  perfect  existence,  b,  section  of 
a  bean-seed,  c,  beed-leaves,  root,  and  the  tirst  true  leaf  of  the 
beech. 


CONSTRUCTION   OF    THE    CATERPILLAR.        137 

rudiments  of  a  leaf  or  of  a  flower  in  the  bud,  that 
Swammerdam  has  given  figures  of  the  parallel  deve- 
lopments 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  unexpanded  buds  of  the  rose,  the  lilac, 
the  horse-chesnut,  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  bestudded  with 
hairs  f. 

The  butterfly  and  the  flower-bud,  however,  differ 
remarkably  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  cater- 
pillar to  occupy  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,  collected  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, 

*  Gicw.  Phys.  Veg.,  ii.  60. 

t  Du  Hamel,  Physique  ties  Arbres,  iii.  1. 

t  See  *  Insect  Architecture,'  p.  309,  D.D.;  and  this  vol.  p.  198, 

i3 


138  INSECT   TRANSFORMATIONS. 

do  not  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  acton 
the  digested  food  in  a  different  manner.  In  caterpil- 
lars, and  in  most  perf»ct  insects,  the  air  is  respired  by 
breathing-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 
ar.d  dies,  as  was  observed  two  thousand  years  ago  by 
Aristotle  t-  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  air  to  the  ves- 
sels containing  the  digested  food,  supplying  it  with 
oxygen  for  the  purposes  of  nourishment.  A  fluid  is  thus 
prepared  analogous  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  analo- 
gous to  blood  may  perhaps  pass  through  this  singu- 
lar'reservoir,  as  water  does  through  blotting-paper  ; 
but  as  yet  this  process  has  not  been  accurately  inves- 
tigated. 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  (Ephemera). 

It  is  further  conjectured  that  the  portion  of  the 
blood  not  immediately  wanted  for  nourishing  the  or- 
gans already  formed,  goes  to  form  a  mass  of  thickish 
mucilage,  contained  in  floating  membranes  of  a  white, 

*  Insect  Archi.  p.  308.       t  Aristotle,  Hist.  Animal.,  viii.  27. 


WATER-GRUB   OF    A   MAY-FLY 


Dissection  of  the  water-ffrub  of  a  May-liy  {Epficmera).  'I'he 
back  is  laid  open,  and  the  nerves,  intestines,  and  respiratory 
apparatus  exhibited,  a  a  a  a  a  a,  six  clnster.s  of  short  tub-s. 
opening  on  both  sides,  througli  which  the  creature  breathes:  the 
air  contained  in  the  water,  jjissiiig  through  these,  enttrs  twcr 
wind-pipes,  h  b  b  b,  rnniuug  from  head  to  tail,  and  circulates 
through  every  part  of  the  boily.  The  eiffht  tins,  ami  a  portinu  of 
the  tail-bristles  have  been  omitted,  to  give  the  rest  of  the  figure 
on  a  larger  scale.    The  central  white  .ines  arc  the  nerveb. 


140  INSECT   TRANSFORMATIONS. 

yellow,  or  green  colour,  and  apparently  analogous  to 
tilt  in  the  larger  animals*.  This  furnishes,  as  is  fur- 
ther supposed,  a  store  of  nutriment  for  promoting  the 
growth  of  the  butterfly  t- 

This  brief  sketch  will  serve  to  give  the  reader  a  tole- 
rable notion  of  the  internal  structJire  of  caterpillars, 
and  the  manner  in  which  their  food  is  elaborated  into 
nutriment ;  but  when  we  know  that  Lyonnet  wrote  a 
large  quarto  volume  on  the  structure  of  a  single  cater- 
pillar, and  that  Maipighi,  Heroldt,  Ramdohr,  Spren- 
gel,  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  structure  and  appearance. 

It  will  be  obvious  from  what  we  have  said  re- 
specting the  colours  of  eggs,  that  we  are  not  in- 
clined to  adopt  in  all  its  extent  the  theory  of  many 
naturalists,  which  maintains  the  peculiar  colours  and 
forms  of  animals  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,  w^e  shall  mention  a  few  facts  which  ap- 
pear 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  grtat  numbers.  Nature  has  provided  an 
immense  abundance  of  them  beyond  what  is  requisite 
for  continuing  the  race.  Were  it  maintained,  there- 
fore, that  they  were  all  by  design  so  formed  and 
coloured  as  to  deceive  the  eyes  of  birds  and  ichneu- 

*  Lyonnet,  Anat.  de  hi  Chemlle,  106. 
f  Reaumur,  Mem.  i.  145. 


COLOURS    AND    FORMS    OF    INSECTS.  14I 

mons,  the  purpose  of  their  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  naturalist,  who  can 
with  ease  perceive  what  escapes  the  observation  of  the 
inexperienced.  When  a  woodpecker  is  taught  by 
Nature  to  detect  a  wood-boring  caterpillar,  by  the 
bark  sounding  hollow  when  tapped  with  his  bill,  and 
wnen  an  ichneumon -fly  can  detect  a  chrysalis  closely 
rolled  up  in  a  leaf*,  we  should  be  strongly  inclined 
to  doubt  that  colour  or  form  could  afford  very  effec- 
tual 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  iew  examples. 

The  caterpillar  of  a  nocturnal  moth  {Nuctua  aliice, 
Fabr.)  is  said  to  assume  the  colour  of  the  lichens 
upon  which  it  feeds,  being  grey  when  it  feeds  on  a 
grey  one  {Parmdia  sajcatUts,  Ach.),  and  always 
yellow  when  it  feeds  on  a  yellow  one  {Cetrariaju/ii- 
perina^  Ach.  t)  ;  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 
{Acronycta  Ligustri^  Ochseniieim.)  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:);  ;  a  circumstance 
explained  upon  the  same  principle.  This,  indeed,  is 
no  uncommon  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,' p.  174-5. 

f  FabrV    orUsung.  in  Kiiby  and  Spence,  ii.  220. 

X  Brahm,  Inseeten,  in  ibid.  p.  221. 


142 


INSECT    TRANSFORMATIONS. 


many  others  should  not  be  similarly  coloured,  when 
we  consider  that  their  stomachs  occupy  the  greater 
portion  of  their  bodies,  and  are  g-enerally  gorged  with 
*bod.  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  grey  or  brown  bark  of  the 
branches  where  they  usually  rest  when  not  feeding. 


Caterpillars  of  the  Clifden  nonpareil  feeding  on  the  grey  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 


Oaterpillars  of  the  Clifden  nonpareil  in  a  more  advanced  stage  of  growth. 

Of  the  extraordinary  tropical  insects  popularly 
tern\ed  Walking--leaves,  belonging  to  several  orders 
and  families  {Locusta,  Mantis^  Phasma,  &c.),  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  re- 
sembling 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  {PhasmatcB,  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.  In  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  {Rnmia  Crat^gata?  Duponchet) 
may  often  be  found,  appearing,  as  it  stalks  along  the 


144 


NSECT   TRANSFORMATIONS. 


Walking-leaf  insect  {Phylliaf  liata,  Dumeril),  magnified. 

whalebones  ofthe  umbrella,  like  a  self-moving- withered 
branch,  the  skin  being  wrinkled  and  furrowed  like 
\he  bark,  while  the  bulgings  ofthe  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  (^Rumia  Cratcpgata). 
a,  the  caterpillar  in  its  resting  position,  b,  the  moth,  c,  the  eggs. 
d,  the  youug  caterpillar. 

We  found  during  last  summer,  on  an  eldf  r,  nt  Tee, 
several  specimens  of  a  similar  walking-branch  ca  er- 
pillar,  that  of  the  swallow-tail  moth  iOurapteryx 
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  or 
*  J.  R. 

K 


146 


NSECT   TRANSFORMATIONS. 


silk,  from  which  the  head  hangs,  in  order  that  they 
may  always  be  ready  to  drop  down  in  safety,  by  extend- 
ing this  thread,  on  the  sudden  approach  of  enemies. 
As  they  feed  chiefly  in  the  night,  they  may  be  seen 
continuing  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.  Rosel's  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 ;  Rrisel,  Insecten,  i.  v.  27, 


COLOURS   AND   FORMS   OF   INSECTS.  147 

persuaded,  however,  that  neither  a  bird,  an  ichneumon, 
nor  a  naturalist,  would  have  been  apt  to  fall  into  such 
a  mistake. 

This  family  of  caterpillars  {Geomdridee,  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  12. 
In  this  position,  laying  hold  with  their  hinder  pro-legs, 
they  stretch  out  their  heads  to  the  full  extent  of  their 
body,  layi-ng  hold  with  their  fore  legs  while  they  bring 
forward  their  body  into  the  Q>  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  shall 
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  blackthorn,  and  called 
by  collectors  the  magpie  {Abraxas  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,  Ocii- 
senheim,),  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  Kirhy  and  Spenre,  Ttitr.  ii.  21')-237. 

K  :? 


148  INSECT   TRANSFORMATIONS. 

butterfly  {Vanesm  Urtic(e),  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.  lo),  also  nettle-leeders,  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  (F.  Afitiopa),  as 
well  as  to  the  conspicuous  caterpillar  of  the  butf-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  p;iven  by  Nature  for  the  purpose  of  con- 
cealment, 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  *'  affords  a 
beautiful  instance  of  the  wisdom  of  Providence  in 
adapting  means  to  their  end."  One  of  those  two- 
winged  flies  {VolucellcB^  Geoffroi),  which  bear  a 
considerable  resemblance  to  humble-bees,  lives  dur- 
ing 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 

*  All  these  caterpillars  are  figured  in  this  volume  :  see  contentu 
of  the  engravings. 


COLOURS   AND    FORMS    OF  INSECTS.  149 

nests  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  forfeit  of  their  presumption  *." 


A  two-winged  fly  (^Fulucclla  plumata,  Meioes'). 

We  do  not  conceive  that  any  dissent  from  this 
doctrine  has  a  tendency  to  weaken  or  destroy  the 
smallest  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,  iu  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  con- 
sidered that  in  the  designs  of  Providence,  as  evi- 
denced by  the  economy  of  nature,  the  nourishment  of 
the  stronger  species  of  carnivorous  animals  is  as 
much  regarded  as  the  means  which  the  weaker  have 
of  escaping  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 

granted  to  do  so  without  leading  us  to  adopt  the 

*  Inlr.  ii.  223. 


150  INSECT  TRANSFORMATIONS. 

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  effectiially  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  enumerating 
examples  of  this,  and  it  will  be  sufficient  to  name  the 
white-ghost  moth  (Hepialiis  Humuli),  which  may 
often  be  seen,  where  hops  or  burdocks  grow,  hovering 
on  the  wing  for  hours  together;  the  satin-moth 
(Leucoma  Salicis,  Stephens),  which  floats  about  the 
air  like  an  animated  flake  of  snow-white  down,  or 
flits  conspicuously  from  tree  to  tree  among  the  higher 
branchea  of  a  row  of  poplars ;  and  the  magpie-moth 
{Abraxas  grossiilariata),  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  com- 
mon 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  flying,  he 
fails  not  to  dart  upon  the  supposed  moth,  and  the 
bur  adhering  to  his  wings,  brings  him  down  to  pay 
the  penalty  of  his  mistake*. 

If  we  leave  colouring  out  of  consideration,  and 
*  J.  R. 


COLOURS   AND   FORMS  OF   INSECTS.  151 

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  appear 
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  caterpil- 
lars occurs  in  that  of  the  pebble-moth  (Notodonta 
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  Vi- 
nula)  is  another  whose  form  and  attitudes  cannot  fail 
to  attract  the  notice  of  the  most  indifferent  observer. 
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  exag- 
geration 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  seem,  therefore,  not  to 
be  afraid  to  deposit  their  eggs  in  its  body  t;  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;^. 

Our  readers  may  like  to  see,  by  way  of  contrast 
to  the  exaggerated  account  quoted  by  Shaw,  the 
excellent  d(^scription  of  the  puss-caterpillar  given 
by  old  Isaac  Walton.     "The  very  colours  of  caterpil- 

''■  Figured  in  Insect  Architecture,  p.  172. 
t  See  ibid.,  pp.  195  and  325-6.  +  J.  R. 


152 


INSECT   TRANSFORMATIONS. 


lars,"  says  he,  "  as  one  has  observed,  are  elegant  and 
beautiful.  I  shall,  for  a  taste  of  the  rest,  describe 
one  of  thetn ;  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 


'l'raii;>foriii,itioDS  of  ih(  puss-irioth  (Cer«ra  Vinului.  n,  the 
rgg.  6  6  6,  young  larvae,  c,  full-grown  Idrva.  'i,  the  pupa,  e,  the 
mo*J». 


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  fttained  with  a  kind  of  red  spots,  which 
run  along-  the  neck  and  shoulder-blade,  not  unlike  the 
form  of  S^  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 
several  kinds  turn  to  be  several  kinds  of  flies  and 
vermin  the  spring  following ;  so  this  caterpillar  then 
turns  to  be  a  painted  butterfly  t-" 

Another  caterpillar,  called  by  collectors  the  lob- 
ster (Stmiropus  Fagi,  Germar.),  which  is  rarely 
met  with,  has  not  only  very  long  legs,  a  circum- 
stance uncommon  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  inditferently  figured  by  him,  as  well  as  by 


Lobster-caterpillar  (^Stauropus  FiKji,  Germab.) 

*  See  Insect  Architecture,  p.  194. 
f  Walton's  Angler,  chap,  v. 

k5 


154  INSECT   TRANSFORMATIONS. 

Albin  and  Donovan  ;  but  Rosel's  figure,  which  we 
here  copy,  is  more  accurate. 

Looking-  at  these  very  sing-ular  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  excep- 
tions, such  as  the  magpie- moth  {Abraxas  grossula- 
rlata),  are  very  different  indeed  from  the  insects  into 
which  they  are  transformed.  Plain  and  inconspi- 
cuous caterpillars  will  sometimes  give  splendidly  co- 
loured insects,  as  in  the  case  of  the  Vanessa  butter- 
flies ;  while  finely  marked  caterpillars  will  give 
plain  insects,  as  the  one  whose  gaudy  stripes  of  sky- 
blue,  scarlet,  and  black,  has  obtained  it  the  appro- 
priate name  of  the  lackey  {Clisiocampa  iieustria^ 
Curtis),  though  the  moth  is  of  a  dull  brownish 
yellow.  Two  of  our  finest  native  insects,  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  larvae  are  aquatic.  One 
of  our  commonest  families  of  insects,  the  gnats  {Cu- 
licidfB,  Latr.),  whose  ingenious  mode  of  constructing 
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  them- 
selves 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  contrary,  they 
*  Spectacle  de  la  Nature,  i.  123. 


ORGANS  FOR  BREATHING  IN  WATER-GRUBS.      155 

usually  swim  near  the  surface  of  the  water,  with  their 
heads  downwards  and  their  tails  in  the  air,  for  a  pur- 
pose which  will  presently  be  obvious.  These  grubs, 
called  sciirrs  in  the  north,  may  be  met  with  in  abun- 
dance during  the  summer,  in  ditches  or  in  water- 
butts  *,  appearing  like  minute,  whitish,  semi-trans- 
parent 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  terminal 
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.  Swammer- 
dam  remarks  that  when,  by  handling  it  too  roughly, 
this  oil  is  removed,  the  grub  "can  no  longer  suspend 
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. 


\ng 


water  *."  The  air,  which  enters  through  several 
openings  in  the  breathing  tube,  passes  onwards  to 
two  lateral  wind  pipes,  very  similar  to  those  of  cater- 
pillars, 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 
g'lobule  of  air ;  and  when  it  wishes  to  re-ascend,  it 
has  only  to  open  its  hair  funnel  again. 


Lhvva  of  tie  coinrnon  pnat  (^Culex  pipiensf)  floating  in  water, 
greatly  magnififi.  a  a,  the  body  and  head  of  the  larva,  b,  the 
respiratory  appar-itus:,  situated  in  the  tail,  c,  the  larva,  not  mag- 
niried. 

A  similar  but  more  elegant  apparatus  for  the  same 
purpose  occurs  in  the  water-grub  of  a  two-winged 
fly,  which  Goedart  called  the  chameleon-fly  {Stratio- 
mys  chamtBleon,  IMeigen),  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  betiutiful  star-like  funnel  of 
thirty  feathered  hairs.  Whether  the  creature  oils  these, 
*  Biblia  NatuPcC,  i.  154. 


ORGANS  FOR  BREATHING  IN  WATER-GRUBS.      157 


like  the  grub  of  the  gnat,  we  know  not,  but  they 
perfectly  repel  water  ;  and  at  the  point  where  the 
insect  hangs  suspended,  a  small  dimple  may  be 
observed  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  pur- 
pose of  breathing  under  water,  is  thus  inclosed  and 
carried  down,  appearing,  as  Swammerdam  says,  like 
a  briUiant  pearl  or  polished  silver.  "  As  for  my 
part,"  he  adds,  "  I  dare  boldly  affirm,  that  the  incom- 
prehensible greatness  of  the  Deity  manifests  itself  in 
these  mysterious  operations  in  a  particular  manner, 
g.nd  affords  us  an  opportunity  of  examining,  as  it 
were,  with  our  senses,  the  divine  nature  *." 


Bsoj-like  struct  ire  in  the  tail  of  a  water-grub  of  a  tvvo-wingcd  fly 
(^Stratiumys  Ckamccleon). 

*  Swammerdam,  part  ii.  51. 


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- 
winged  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  oftheovipositorof  the  breezeflies*, 


Telescopic-tailed  water  larvae,  a,  a  glass  vessel  of  water  con- 
taitiiirg  the  larvae,  natural  size,  b,  ma£;nified.  view  of  the  tail, 
with  the  breathing-tube  partially  contracted,  c,  a  still  more  en- 
larged 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  Reaumur 
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  ])ushes  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   (iVats).      ana.   half-conceakd   in  the   sand, 
b  b  b,  their  sand-tubes  exposed. 


160  INSECT  TRANSFORMATIONS. 

It  may  not  be  improper  to  guard  our  younger 
readers  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 
(Nais),  upon  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- 
water worm,  which  medical  men,  unacquainted  with 
natural  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  {LibeUulidcB^  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-stingers, 
since  they  have  no  apparatus  for  stinging  ;  "  and  so 
far,"  says  Reaumur,  "  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  larg^ 


STRUCTURE    OF    LARV^.  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 
time,  the  desire,  or  necessity,  of  respiration  is  increased, 
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  tiie  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,  an  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  reverbe- 
ratory  current  brings  small  water-insects  within  its 
reach  ;    it  is  also,  it  would  appear  partly  appropriated 


162 


INSECT   TRANSFORMATIONS. 


to  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.  Grab  of  a  dragon-fly;  b  h,  the  body  laid  open  and  magnified, 
to  .-.how  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- 
va?, which  is  probably  unmatched  in  the  insect  world. 
In  the  larvaB  of  most  insects  the  under-lip  is  small 
and  inconspicuous,  but  in   those  of  the   dragon  flies 

•  De  Geer,  ii.  666,  antl  ReaumuPj  vi.  393,  &c. 


STRUCTURE    OF    LARVAE.  J  63 

"  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  Reaumur  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  elonga- 
tion 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  numerons  sharp 
teeth,  or  spines,  or  armed  with  one  or  more  long 
sharp  claws; — you  will  then  ha\e  as  accurate  an 
idea  as  my  powers  of  description  can  give  of  the 
strange  conformation  of  the  under-lip  in  the  hirvse  of 
Libellidina,  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 


161 


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  unJoid  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  opera- 
tion of  the  two  pairs  of  jaws  with  which  they  are  pro- 
vided. Reaumur  once  found  one  of  them  thus  hold- 
ing and  devouring  a  large  tadpole  ;  a  sufficient  proof 
that  Swammerdam  was  greatly  deceived  in  imagining 
earth  to  be  the  food  of  animals  so  tremendously  armed 
and  fitted  for  carnivorous  purposes.  In  the  larvsB  of 
LibeUula,  Fabr.,  it  is  so  exactly  resembling  a  mask, 
that  if  entomologists  ever  went  to  masquerades,  they 
could  not  more  effectually  relieve   the   insipidity  of 


The  mask    of  the  dragon-fly  grub,   in   four   diflferent    states  of 
opening  and  shutting. 

such  amusements  and  attract  the  attention  of  the  de- 
moiselles than  by  appearing  at  the  supper-table  with  a 
mask  of  this  construction,  and  serving  themselves  by 
its  assistance.     It  would  be  difficdt,  to  be  sure,  by 


STRUCTURE   OF    LARVAE.  165 

mechanism,  to  supply  the  place  of  the  muscles  with 
which  in  the  insect  it  is  amply  provided  ;  but  Merlin, 
or  his  successor,  has  surmounted  greater  obstacles*.'' 

The  larvae  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  sur- 
prise: so  artful  are  they,  that  insects,  and  even  small 
fishes,  find  it  difficult  to  elude  their  attacks •}-. 

The  larsa  of  a  very  singular  insect  {Reduvius per- 
sonalus,  Fabr.),  which  preys  upon  the  bed-bug 
{Cimix  lectular ins),  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  choose,  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  pnuses  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 
usually  abandons  its  covering. 

*  Introd.  to  Ent.  iii.  126.  f  De  Geer,  ix.  674. 


16G 


Chapter  VII. 

Growth,  Moulting,  Strength,  Defence,  and  Hybernation  of  Larvs;. 

From  the  facts  being-  commonly  known,  we  are  not 
surprised  that  an  ostrich,  nine  feet  high  and  150  lbs. 
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  {Phylolacca  dioica  ?),  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  econom.y  of  trees  springing  from 
seeds  and  birds  being  produced  from  eggs.  When  we 
repeat,  after  Lyonnet,  that  the  caterpillar  of  the  goat- 
moth  (Cos.s^wsZ/jg-nzjwerrfa,  Fab  r.)  becomes  72,000  times 
heavier  than  when  newly  hatched  f,  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. 


67 


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. 


A  hundred  worms  just  hatched  weigh  about 

After  the  first  moulting 

After  the  second  moulting 

After  the  third  moulting 

After  the  fourth  moulting 

On  attaining  their  greatest  size  and  weight 


GRAINS. 

1 

15 

94 

400 
4628 
9500 


They  have,  therefore,  in  thirty  days  increased  9,500 
times  their  primitive  weight. 

Progressive  increase  of  silk-worms  in  length. 


4 

6 
12 

20 
40 


A  silk-worm  just  hatched  measures  about 

After  the  first  moulting 

After  the  second  moulting         . 

After  the  third  moulting 

After  the  fourth  moulting 

After  the  fifth  moulting  it  may  reach 

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 
caterpillars  with  buds,  which  ought  to  be  taken  (if 
we  may  trust  Swammerdam)  literally  rather  than 
poetically,  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,  beinj^  thence  protected,  remain  soft  and 
pulpy.  But  as  soon  as  the  inner  leaves  receive  au 
accession  of  sap,  which  rises  from  the  roots  on 
the  return  of  sprino;,  their  vessels  swell  and  their 
nervures  expand  ;  while  the  outer  leaf,  from  its  ves- 
sels being  shrunk  and  partly  obliterated,  undergoes 
little  change  besides  being  pushed  out  and  some- 
times entirely  thrown  off  by  the  growth  of  the  inner 
leaves,  which  it  had  previously  inclosed.  It  may  he 
remarked,  also,  that  this  outer  envelope  of  a  bud  is 
not  united  with  the  inner  leaves  by  any  interlacing  of 
their  substance  or  of  their  vessels,  though  in  some 
cases  there  is  an  adhesive  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  nou- 
rished 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  body  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  mo- 
tionless. 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  Ijody  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.  185. 

h 


170  INSECT  TRANSFORMATIONS. 

like  a  worn  shirt;  and  the  caterpillar  appears  in  an 
entire  new  dress,  the  tints  of  whicli  are  fresher  and 
brighter,  and  the  colours  and  marking-s  often  con- 
siderably different  from  the  former.  The  insect, 
also,  in  consequence  of  the  quantity  offat  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,  par- 
ticularly 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  dissec- 
tions which  have  been  made  by  Svvammerdam,  Lyon- 
net,  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  shiivelled  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  of  Kent  {Endi'omis  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,  and  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  *.  Re'aumur  mentions  th.e 
very  singular  circumstance  of  a  caterpillar  of  the 
six-spot  burnet-moth  (Anthrocera  Filipendidce,  Ste- 
phens) 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 
man(£uvre,  or  the  usual  process  of  this  species  of 
caterpillar  t ;  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  Dandolo  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  swailowed, — a  process  which  often 
terminates  in  the  production  of  an  ac'd  ;  and  as 
acids  have  a  tendency  to  redden  ve{::etable  colours, 
the  red  blotches  are  plausibly  ascribed  to  that 
cause.  This  conjecture,  which  originated  with 
Count  Dandolo,  has  been  proved  to  be  the  fact  by 
Professor  Brngnatelli ;  who  made  the  very  unexpected 
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  {Lithia  renalis  ft,  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  arrives. 

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  diarrhoea,  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,  sheathed 
in  the  hairs  of  the  old  skin,  but  smoothly  folded 
down   in    separate    tufts;    and   if  the  old  skin  be. 


I 


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  camel's-hair  pencils,    lying 


Moulting  of  caterpillars,  a  a,  caterpillar  magnified;  6  b, 
the  same  when  it  has  just  cast  its  skin,  the  hairs  still  moist; 
c,  the  same,  natural  size;  d  e  f  g.  tufts  of  its  hairs  magnified; 
h,  leg  and  foot  magnified  ;  t,  the  caterpillar  wedging  through  the 
old  bkin  ;  ft  k,  hairy  caterxiillav  of  the   hycamore. 

l3 


174  INSECT  TRANSFORMATIONS. 

close  to  the  inner  skin, — those  on  the  fore  part  of  the 
body  laid  towards  the  head,  and  from  the  fourth  ring 
backwards  in  a  contrary  direction. 

Swammerdam,  Reaumur,  and  other  naturalists, 
repeatedly  tried  the  experiment  of  cutting;  off  the 
hair  from  caterpillars  about  to  moult,  without  in  the 
least  affecting-  the  hairs  on  the  new  skin  ;  but  when  a 
foot  or  any  other  member  is  accidentally  mutilated,  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,  ascer- 
tained by  Swammerdam,  De  Geer,  Lyonnet,  and 
Bonnet,  that  caterpillars  and  grubs  not  only  cast 
their  external  skins,  but  also  that  which  lines  their 
breathing-tubes  and  intestines.  "  Some  days,''  sajs 
Bonnet,  "  before  the  change,  the  caterpillar  voids 
along  with  its  excrements  the  membrane  which  in- 
vests 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  inte- 
rior spiracles  of  a  butterfly  remain  attached  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  sto- 
mach of  a  lobster,  or  of  a  caterpillar.  Lyonnet,  in 
some  measure,  confirms  this  conjecture  *. 

In  his  admirable  description  of  the  rhinoceros- 
beetle  {Oryctes  iiasiconiis),  Swammerdam  says  of 
the  grub:  "Nothing  in  all  nature  is,  in  my  opinion, 
a  more  wonderful  sight,  than  the  change  of  skin  in 
these  and  other  the  like  grubs.  This  matter,  there- 
fore, deserves  the  greatest  consideration,  and  is  wor- 
thy to  be  called  a  specimen  of  Nature's  miracles.  For 
*  Bonnet,  CEuvres,  vol.  viii.  pp.  303-311. 


MOULTTNG    OF    GRUBS. 


75 


it  is  not  the  external  skin  only  that  these  grubs  cast, 
like  serpents ;  but  the  t  hroat  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  wonders ;  for  at  the  same  time  some  hun- 
dreds of  breathing-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  respiration,  cast  a  skin 
likewise.  If  any  one  separates  the  cast  little  ropes  or 
jongeries  of  breathing-pipes  with  a  fine  needle,  he 


Exuvia  and  pulmonary  vessels  of  the  rhinoceros-beetle  [OrycteB 
nasicornis^.  A,  niae:nified  view  of  a  pulmonary  branch  and 
vesicle  ;  na,  pnlmonary  branch,  composed  of  a  membranous  sheath 
and  cartilaginous  ritig:s;  6,  vesi(;le.  B,  larva;  c  c,  nine  reddish 
breathing-holes.  C,  exuvia,  or  cast  skin  of  the  larva;  d  d  d  d, 
skins  of  the  pulinoiidry  tubes. 


17f)  INSECT    TRANSFORMATIONS. 

will   very   distinctly   see  their  several  branches   and 
ramifications,  cind  also  their  ring'ed  structure*." 

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  {Ai'ctia  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 
previously  absorbed,  there  is  no  stimulus  for  it  to  eat. 
But  as  soon  as  this  supply  is  exhausted,  it  com- 
mences 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  slig-ht  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  springt;  and 
quadrupeds  in  a  similar  way  cast  their  hair.  But 
in  both  these  cases  the  process  is  gradual,  and 
resembles  that  of  shedding  the  milk-teeth  when  the 
jaw  enlarges.  All  of  these  changes,  hov/ever,  pro- 
duce considerable  derangements  in  the  animals  ;  and 
they  are  seldom  accomplished  without  disordering 
health,  and  sometimes  endangering  life.  The  great 
difference  between  the  changes  iu  insects  and  the 
other  classes  of  animals  evidently  urises  fi"om  the 
difference  of  their  internal  structure.  It  must  be 
obvious  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 

*  Svvammeidam,  Bib.  Nat.  vol.  i.  p.  135. 
+  Teinminck,  Manuel  d'Ornilhol.  Iiitr 


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 
provided  for  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.  No  similar 
process  of  removing  worn  materials  has,  so  far  as  we 
know,  been  discovered  in  caterpillars ;  and  it  is, 
indeed,  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  spinous 
or  hairy  ones  seem  to  relish  this  strange  sort  of  food. 
In  the  case  of  the  warty-eft  {Triton  palustris, 
Flem.),  which  frequently  casts  its  outer  skin,  we 
have  observed  that  it  is  frequently  eaten  by  the  animal 
itselff. 

The  grubs  of  some  two-winged  flies  {Muscidce)^ 
and  of  wasps,  bees,  ants,  and  ichneumon-flies,  do 
not  change  their  skins  like  the  larva?  we  have  just 
been  considering;  but  spiders  and  other  allied  tribes 
{Arach?iid(E),  though  they  exhibit  no  other  appear- 
ance of  larvae,  moult  frequently  during  their  growth. 
Goldsmith,  amongst  other  curious  mistatements  re- 
specting a  house-spider  which  he  himself  observed, 
asserts  that  it  "  lived  three  years,  every  year  it 
changed  its  skin,  and  got  a  new  set  of  legs  :  I 
have  sometimes  plucked  otf  a  limb,  which  grew 
*  Bonnet,  (Euvies,  vol.  ii.  p,  18.  f  .).R, 


178 


INSECT    TRANSFORMATIONS. 


again  in  two  or  three  days,"  The  fact  is,  that  few 
spiders  hve  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  Gold- 
smith never  thought  of  ascertaining  the  identity 
oC  this  spider,  if  the  w^iole  story  be  not  a  mere 
fancy,  like  his  assertion,  that  spiders,  "when  they 
walk  upon  sucli  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*."  Neither  spiders  nor  any  injects  with 
which  we  are  acqnainted  can  thus  produce  gum 
from  their  feet  to  aid  them  in  walking  upon   glass. 


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  Architfc 
lure,  pp.  367-8. 


MUSCULAR    STRENGTH    OF    INSECTS.  179 

though  the  house-fly  can  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  con- 
structing a  ladder  of  ropes,  as  is  represented  by 
Rosel  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  Hallcr  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  {Tetiigonia  spn- 
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. 

f  Haller,  Physiul.,  vol.  ix.  p.  'J. 
%  De  Geer,  Mem.,  vol.  iii.  p.  178. 

^.  .-\iist(.ph;ir!cs,  Nsf  :?.«<,  «,  /3. 


180  INSECT   TRANSFORMATIONS. 

Sir  Joseph  Banks  and  the  emperor-butterfly.  To 
all  such  flippant  wit  we  have  merely  to  retort  the 
question  vf  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  f,  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  sitting  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 
})ersons  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|.  Gold- 
smith remarks  upon  these  displays  of  pulician 
strength,  that  the  feats  of  bamson  would  not,  to  a 
community  of  fleas,  appear  to  be  at  all  miraculous  § 
Latreille  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  off  [j.  Prolessor  Bradley, 
of  Cambridge,  also  mentions  a  remarkable  instance 
of  insect  strength  in  a  stag-beetle  {Lucanus  Cerviis) 

*  Spectacle  de  la  Nature,  i.  3.  f  Page  273. 

X  Animal  Biography,  iii.  468.     §  Animated  Nature,  iv.  178. 

II  Nouv.  Dict.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.  *'  I  have  seen,"  says  Sir 
Gilbert  Blane,  "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 f."  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 
lieshy  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  Sir  Gilbert  Blane,  Select  Diss.  p.  281. 

M 


18-2  INSKCr    TRANSFORMATIONS. 


—       _z^^ 


,^eW. 


MiWImh 


I  ^: 


^0i 


lllll 


'i.H^i 


mm 


?fc 


M;  gnified  view  ol  tht^  jrincipal  dorsal  muscles  of  the  upper  half  of  the 
Cossus,  from  Lyonntt. 


MUSCULAR   STRENGTH   OF   INSECTS.  183 

common  to  the  head  and  gullet,  gives  a   total    of 
4061* 

"  Any  lady,"  say  Kirby  and  Spence,  "  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  caterpil- 
lar undei  the  microscope:  with  wonder  and  delight 
she  would  survey  the  innumerable  muscular  threads 
that  in  various  directions  envelope  the  gullet,  stomach, 

I  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  t." 

We  put  the  caterpillar  of  the  goat-moth,  to  which 
We  have  before  alluded,    under  a  bell-glass,   which 

j  weighed  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 — 
"  Loudon'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|. 
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  feat  was  performed.  Even  this  power 
of  muscle,  however,  would  doubtless  have  been  un- 

»  Lyonnet,  Traite  Anat.  de  la  Chenille,  pp.  188,  584. 
t  Intr.iv.  186.  +  J.  R. 

u  2 


184 


INSECT   TRANSFORMATIONS. 


availing;  in  raising  the  loaded  glass,  except  in  con- 
nexion with  two  favourable  circumstances  under 
which  the  experiment  was  performed,  and  which  are 
necessary  to  be  borne  in  mind  to  render  the  opera- 
tion perfectly  credible: — 1st,  that  the  wedge-like 
form  of  the  caterpillar's  head,  in  connexion  with  the; 
peculiar  shape  of  the  glass,  enabled  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 
grey  shoulders  and  a  brown  abdomen,  {Eristalis 
tmax,  Fabr.).  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 

cliinery,  it  has  survived  in  a  miraculous  manner. 
Such  is  the  account  originally  ^iven  by  Linnaius*. 
A  recent  compiler,  mistaking  Kirby  and  Spence'svery 
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  ol 
the  caterpillar  (figured  at  page  125)  of  the  privet 
hawk-moth  {Sphinx  Ligudri),  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  happened  f. 

The  instances,  however,  which  we  have  just  re- 
corded are  peculiar  rather  than  gtneral,  for  cater- 
pillars are  for  the  most  part  very  easily  bruised  and 
otherwise  injured.  Those  which  are  large  and  heavy, 
therefore,  such  as  the  caterpillars  of  the  hawk-moths 
(^Sjj/iingidfe),  have  the  powerof  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 alwajs  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  acci- 
dentally forced  to  quit  their  situation.  Their  method 
of  climbing  up  this  cable  again  is  worthy  of  observa- 
tion ;  for  it  differs  considerably  from  the  manoeuvre 
of  spiders,  under  the  same  circumstarices,  as  must  Ixj 

*  F'auna  Suec.ica,  1799. 

t  Bonnet,  Giluvr-es,  vol-,  ii.p.  124. 

4  See  Ini^ecl  Architecture,  p.  307,  right-hand  figure. 


186 


INSECT  TRANSFORMATIONS, 


obvious,  when  we  consider  that  the  spinneret  of  the 
spider  is  placed  near  its  tail,  while  that  of  the  cater- 
pillar is  in  its  mouth.  The  spider  accordingly  drops 
head  downwards*,  but  when  it  wishes  to  remount  i 
the  line,  it  turns  round,  and  raising  its  head,  it  i 
stretches  its  long  triple-clawed  legsf  up  the  line, 
which  it  bundles  up  while  it  ascends.  The  cater- 
pillar, on  the  other  hand,  having  very  short  legs,  with 
only  one  smooth  claw  |,  would  make  but  slow  pro- 
g-ress  in  this  manner,  which  it  does  not  attempt ;  but 
trending  its   head   downwards  till  it  can  grasp  the^ 


Methods  used  by  spiders  and  caterpillars  for  ascending  their 
threads.  The  caterpillars  are  those  of  the  emperor-inotk 
(^Saturnia  Pavonia). 

♦  Insect.  Archit.,  page  336.  f  Ibid.,  p,  367. 

I  Ibid.,  p.  307,  left-himd  figure. 


i 


MEANS  OF  DEFENCE  OF  CATERPILLARS,   1&7 


cord  with  its  hinder  pair  of  feet,  and  then  raising  its 
head  to  the  perpend icnhir  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  tliread,  taking  advantage,  for  this  pur))ose, 
of  the  long  hairs  which  cover  their  body.  Those 
who  have  seen  a  hedge-hog  (Erinaceas  E^iropceus), 
when  attacked  by  a  dog,  roll  itself  up  into  a  prickly 
ball,  will  readii}  concei\e  the  manceuvre  of  the  cater- 
pillais  to  which  we  allude,  it  being  preeiselj  similar. 


ms^:^'^'''"'^^ 


\ii' 
#" 


^y%|||///,^y;;;/^ 


a,  Cateip  liar  of  (he  tigei  moth  (^Aictia  <\i>n)  b,  the  s.ame, 
rolled  up  toi  defence  t,  gniL  of  the  museum-beetle,  d,  the 
hame  itiagmtied.  e,  tail  of  the  batne,  raagiiihed  /,  g,  Us  hairb, 
lllagnl^^.d. 


188  INSECT   TRANSFORMATIONS. 

Sliould  one  of  those  hairy  caterpillars,  when  feediiijj 
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 
sinoothness  of  the  hair  causes  it  to  slip  through  the 
fingers  as  readily  almost  as  quicksilver.  The  grub 
of  the  museum-beetle  {Anthreiius  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 
composed  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  {Annadillo  vulgarifi,  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.  ''  One  of  our  maid-ser- 
vants," sajs  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  began  to  put  them  one  after  another 
on  a  thread ;  it  soon  happened  that  the  littl^  crea- 
tures, 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 
tliread  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 
{Vanessee).     We  have   alluded   to   that  of  the   pea- 

♦  *wammerdam,  pt.  i.  p.  174 


MEANS  OF  DEFENCE  OF*  CATERPILLARS.   189 


cock's  eye,  which  must  be  conspicuous  to  birds  from 
its  dark  hhick  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  Leiliis  are  as  hard  as  iron  wiref."  Abbot 
tells  us  that  many  American  caterpillars  sting  like  a 


Thorny  hairs  of  caterpillars,    a  a  a,  spiny  caterpillar,  from 
i\ladrtme  Merian.     bb,  Vanessa  lo.    c,  spines,  magnified. 

Wiihering,  Bot.  Arraiigemetit.     Note  on  Ilex  aquifoUum, 
f  Merian,  Insect.  Surinam,  xxix. 

M  5 


190  INSECT   TRANSFORMATIONS, 

nettle,  and  blister  the  skin  when  touched  ;  which  is 
also  partly  exemplified  in  that  of  our  own  gipsey-inoth 
(Hypogymna  dispar),  the  slender  hairs  of  which 
irritate  and  inflame  the  skin.  The  spines,  in  some  of 
the  caterpillars  alhided  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  Imatidium  Leayanuin) 
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  i\\it\\\y  (^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 
*  Linn.  Trans,  iii.  10. 


MEANS  OF  DEFENCE  OF  CATERPILLARS,   191 

tlie  two  preceding' insects,  thisf!;rub  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.  Cassicla  equestris.     B,   its  grnh,  magnified  to  shew  its  anal 
forks.     C,  the  same  with  its  canopy  of  excrements. 

The  larvae  of  the  golden-«yed  fly  {Chrysopa  perla^ 
Leach),  whose  very  singular  eggs  we  formerly  men- 
tioned, covers  itself  with  the  fragments  of  the  apliides 
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 
{Ttttigonia  spumaria,  Olivier),  so  frequently  seen 
in  summer  on  willows,  rose-trees,  lychnis,  grass,  and 
other  plants.  This  creature  is  of  an  exceedingly  soi>. 
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. 


102  INSECT   TRANSFORMATIONS. 


rt.The  spit-  frog-hopper  (Tettigonia  spumnria)  flying, 
covering  the  grub  of  the  same. 


h,  froth 


amounts  almost  to  demonstration,  from  a  circum- 
stance discovered  respecting  ants  by  the  younger  Ru- 
ber. '*  The  larvae  of  some  ants,"  says  he,  "  pass 
the  winter  heaped  up  in  the  lowermost  floor  of  their 
dwelling'.  I  have  found,  at  this  period,  very  small 
larvae  in  the  nests  inhabited  by  the  yellow  ant  {For- 
mica Jtava),  the  field-ant  (F.  coespitum  ?),  and  some 
other  species.  Those  that  are  to  pass  the  winter  in 
this  state  are  covered  with  hair,  which  is  not  the  case 
insununer;  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  t. 

Upon  the  same  principle,  a  number  of  the  cater- 
pillars which  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 
€ven  with  most  of  those  which   construct  for  theoi- 

*  N.  P.  Hiiberon  Ant?,  p.  82. 
t  See  Menageries,  vol.  i.,  p.  50. 


MEANS  OF  DEFENCE  OF  CATERPILLARS.   193 

selves  a  snug-  nest  of  silk,  such  as  the  caterpillars  of 
the  brown-tail  moth  (Porthesia  aurifliid),  and  those 
of  ihr.  mallow-butterfly  {Heaperia  malv^).  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  {Arctiacaja,  Stephens),  whose  mode  of 
rolling  itself  up  into  a  ball  we  have  already  described; 
but  a  more  remarkable  example  occurs  in  the  cater- 
pillar of  the  drinker-moth  {Odo?iestis  potatoria, 
Germar.),  whose  very  feet  are  covered  with  fine 
shaggy  down.  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  withered  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  Febru- 
ary, when, owing  to  neglect,  it  unfortunately  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 
cot)tinue  to  feed,  but  become  wholly  or  partially  tor- 
pid, such  as  the  caterpillar  of  the  magpie-moth 
{Abraxas  grossulariata).  Of  this  species  we  have 
observed  numbers,  about  as  thick  as  a  crow-quill, 
remaining  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. 


194 


INSECT   TRANSFORMATIONS. 


within  their  choice,  being  usually  found  on  an  exposed 
currant  branch,  or  under  the  upper  cross-bar  of  a 
paHng.  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 
keeping  them  in  a  warm  room  ;  but  though  they 
would  make  a  few  lethargic  and  unwilling  move- 
ments, 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 


a,  Young  caterpillar  of  thedrinlvcr.  6,  the  same,  full  grown. 
c,  smooth  caterpillar  of  the  angle-shades.  d,  the  Diolh  of  the 
same. 

*  J.R. 


HYBERNATION   OF    CATERPILLARS.  195 

from  particular  facts  seldom  accord  with  actual  na- 
ture, and  ought  never  to  be  indulged  in  by  natural- 
ists 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  me- 
ticulcsa,  Ochsenheimer).  This  caterpillar,  which  is 
exceedingly  smooth,  and  is  remarkable  for  changing 
in  its  last  moult  from  a  clear  green  to  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  torpidity. 

Some  caterpillars  seem  to  have  no  less  power  of 
resisting  severe  cold  than  eggs ;  as  authentic  in- 
stances 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  stoneb 
when  thrown  into  a  glassf;  and  Mr.  Stickney  ex- 
posed some  grubs  of  a  common  crane-fly  {Tipula 
oleracea,  Linn.)  to  a  severe  frost,  till  they  were  con- 
gealed into  masses  of  ice,  yet  several  of  them  sur- 
vived |.  Reaumur,  however,  was  unsuccessful  in 
similar  experiments  on  the  gregarious  moth  of  the 
fir  {Cnethocampa  Pityocampa,  Stephens),  so  cele- 
brated among  the  ancients  as  a  poison  §  ;  for  none  of 
them  survived  a  cold  of  2°  below  zero,  Fahr.,  by 
which  they  were  frozen  to  ice||. 

*  John  Hunter,  Obs.  on  Anim.  Econ.  p.  99. 

f  Goedart,  Insect,  p.  79.         J   Kirby  and  Spence,  Inlr.  ii.  p.  453. 

§  Piin.  HUt.  Nat.  38,  9.  IJ  Mem.  ii. 


19f) 
Chapter  VI IF. 

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  ei:^g,  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  larvie  of  insects 
doze  away  a  day  or  more  when  casting  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  (Miisca  cm- 
naria)  becomes  from  140  to  200  times  hea^;ier  within 
twenty-four  hours  t ;  and  the  cultivators  of  silk-worms 
know  the  exact  quantities  of  leaves  which  their  broods 
devour.  *'  The  results,"  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  lbs.  8  oz.,  divided  in  the 
following  manner : — 

*  Account  of  the  Works  of  Nature, 
t  Esperienze  de  Itisetli,  p.  23. 


VORACITY    OF    CATERPILLARS,  197 

Sorted  leaves.     Refuse, 

lbs,  oz.  lbs.  oz. 

First  age 6  0  1     8 

Second  age 18  0  3    0 

Third  age 60  0  9     0 

Foi.rtli  age 180  0  27     0 

Fifth  age 1098  0     102     0 

Per  ounce  of  esfgs  of  sorted  leaves. ...  Ihs. 1362     0      142     8 
Refuse \ 142     8 

Lost  from  the  leaves  by  evaporation,  &c.  . .    105     0 

1609  8 
He  adds  to  this  curious  table,  that  from  the  1362  lbs. 
of  sorted  leaves  given  to  the  caterpillars,  it  is  neces- 
sary to  deduct  155  lbs.  7  oz.  4  drs.  of  litter,  consist- 
ing of  fragments  of  uneaten  leaves,  stalks,  fruit,  &c., 
and  consequently  that  they  actually  devour  only  1206 
lbs.  4  oz.  4  drs.  It  is  necessary  also  to  mention  that 
of  this  quantity  745  lbs.  8  oz.  of  dung  are  carried  from 
the  hurdles  ;  and  consequently  there  is  only  digested 
771  lbs.  7  oz.  4  drs.  of  pure  leaves,  which  produce 
120  lbs.  of  silk  cocoons, — giving  a  loss  by  evaporation 
from  the  worms  in  gas  and  vapour  of  496  lbs.  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 
produced  from  1  oz.  of  eggs,  which  is  upwards  of 
1200  lbs.  A  single  silk- worm,  as  we  before  men- 
tioned, 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, 
Kng.  Trans!. 


198  INSECT   TRANSFORMATIONS. 

v^ry  extraordinary  accuracy,  enumerates  nearly  2000 
species  of  native  moths  and  butterflies;  and  as  the 
females  of  tiiese  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  g'rubs  and  mag-g'ots  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  insects.  What  is  no  less  wonderful, 
a  corresponding;  change  takes  place  in  the  internal 
formation  of  their  organs  of  dig-estion.  A  cater- 
pillar will,  as  we  have  seen,  devour  in  a  month 
60,090  times  its  own  weight  of  leaves,  while  the 
moth  or  the  butterfly  into  which  it  is  afterv/ards  trans- 
formed may  not  sip  a  thousandth  part  of  its  weight 
of  honey  during  its  whole  existence.  Now,  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  dissections, 
conducted  with  great  skill,  Heroldt  traced  these 
changes,  as  they  successively  occur,  from  the  cater- 
pillar 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 


I 


VISCERA   OF   THE    COSSUS.  193 

View  of  the  upper  side.  View  of  the  under  side. 

-A  M 


Bi 


A,  B,  C,  The  oeso- 
phagus and  its  ap- 
pendatres. 

D,  K,  The  sto- 
mach ; — a  pair  of 
muscles  wind  spi- 
rally round  it,  and 
by  their  contraction 
s(|iieeze  the  digested 
fo 'd  into  the  intes- 
tines, 

E,  F,  The  first 
large  intestine.  F, 
G,  the  second.  G, 
H,  the  third. 

1,1,  The  six  small 
intestines, 


P 


H 


h: 


Viscera  of  the  Cossus. 


200  INSECT  TRANSFORMATIONS 


A— A,  Caterpillar  of  Vanessa  urticae,  magnified,  a—k,  the 
intesiines  of  the  same,  a,  the  gullet.  6  6  h  b,  pulmonary  tubes, 
cf,  ligament  of  the  stomach.  d  d  d  d,  transparent  nnijs  of  the 
same,  e  e,  small  intestines.  //,  their  origin.  (7/7  ^ /i,  their  wind- 
ings,    i  k,  the  rectum. 


NTESTINAL  STRUCTURE. 


201 


tLe  gullet,    and  in  the  butterfly  is  enlarged   into   a 
honey  stomach. 


Intesrinal  canals  of  the  caterpillar,  pupa,  and  butterfly. 

1.  Caterpillar,     «,   the   oesophagus,     b,   the    stomach,     c  d,   the 

two  large  inte^itines. 

2.  Pupa  two  days  old,     a,   the  oesophagus,     h,  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    iu)mediafely  before  its   transformation,     a,  the  honey- 

stomach  become  a  lateral    appendage  of  the  oesophagus.    6, 
the  stomach,     c  d,  the  larg:e  intestines. 

5.  Butterfly,     a,  honey-stomach,    b,  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,  Cui  len), 
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  tlie  case  with  the  French  prisoner-at  I^iverpool, 
who,  on  the  testimony  of  Dr.  Cochrane,  consumed, 
in  one  day,  sixteen  pounds  of  raw  meat  and  tallow 
candles,  besides  five  bottles  of  porter  f. 

The  mandibles  of  caterpillars,  which  do  not  act 
perpendicularly  like  the  jaws  of  quadrupeds,  bat  ho- 
rizontally, are  for  the  most  part  very  sharp  and  strong, 
being  of  a  hard,  horny  substance,  and  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  ofthe  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  {inaxillce)  placed  on  each  side 
ofthe  middle  portion  ofthe  under  lip  ;  and,  from  their 
being  of  a  softer  substance,  they  seem  to  be  more  for 
the  purpose  of  retaining  the  food  than  for  mastication. 
This  formidable  apparatus  for  masticating  {Trophi) 
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  destructivencss  ;  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.  l^eroy  in  Rapport  d'Institute  Nalionelle. 
t  Med.aiid  Phys.  Tourn.  iii.  209.      J  Cuvier,  Aitat.  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  extra- 
ordinary 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  exagge- 
rated ;  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  sort  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  cater- 
pillars did  not  abound  f. 

Instances  like  this,  however,  from  solitary  species, 
are,  we  believe,  less  common  than  those  of  the  ravages 
of  gregarious  caterpillars.  In  1S26,  colonies  of  the 
butf-tip  {Pygcera  bucepliala,  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  Us  moth  in  '  Insect  Archi- 
tecture,' pp.  162-3.  t  J.  R. 


204 


INSECT   TRANSFORMATIONS 


scarcely  leavinf^  a  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, 
appeared  with  the  one-half  of  their  branches  leafless 
and  naked,  while  the  other  half  was  untouched. 
Besides  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  hulf 
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  (^Pygrpra  hucephahi).  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  by  d(  zens*. 

Those  caterpillars  v\hi(h  teed  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  tlie  lackey-caterpillars  {Clisio- 
campa  neusiricC),  which  are  what  naturalists  term 
polyphagous  feeders,  that  is,  they  do  not  confine  them- 
selves to  a  particular  sort  of  tree,  but  relis>h  a  great 
number.  The  hawthorn,  the  blackthorn,  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  (Jljoo- 
nomtuta  padella),  which  does  not,  besides,  feed  quite 
so  indiscriminately  ;  but  when  the  bird-cherry  {Pru- 
nuspadus),  rts  peculiar  food,  is  not  to  be  had,  it 
will  put  up  with  blackthorn,  plum-tree,  hawthorn, 
and  almost  any  sort  of  orchard  fruit-tree.  With  re- 
spect to  such  caterpillars  as  feed  on  different  plants, 
Reaumur  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  f. 
We  verified  this,  in  the  case  of  the  caterpillar  in  ques 
lion,  upon  two  different  nests  which  we  took  in  1806, 
from  the  bird-cherry  at  Crawfordland,  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  insects,  and  imagining  they  would  eat  any 
sort  of  leaf,  we  tried  them  with  almost  every  thing 
*  J.  R.  t  De  Geer,  Mem.  i.  319. 

N 


206 


INSECT   TRANSFORMATIONS. 


green  in  the  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  sum- 
mer (18:29)  we  again  tried  a  colony  of  these  cater- 
pillars, found  on  a  seedling  plum-tree  at  Lee,  in 
Kent,  with  blackthorn,  hawthorn,  and  many  other 
leaves,  and  even  with  those  of  the  bi rd- cherry  ;  but 
they  would  touch  nothing  except  the  seedling  plum, 
refusing  the  grafted  varieties*. 


Encampment  of  the  caterpillar  of  the  small  ermine  (^Yponomeula 
padtita)  on  the  Siberian  crab. 

A  circumstance  not  a  little  remarkable  in  so  very 

nice  a  ieeder  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  (Pi/rus  pninifolia,  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  aleaf  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 
terseaand  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 
.xperiment*.  This  present  spring  (1830)  they  have 
again  appeared  in  miilions  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 t,  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  produces 
the  prettiest  moth  of  the  genus  {Yponomeuta Euony- 
mella)  ;  but  our  preceding  remarks  all  apply  to  one 
species. 

In  1829  we  remarked  a  very  extraordinary  num- 
ber of  webs  of  some  similar  caterpillar,  oi  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 
*  '.  R.  t  Reaumur,  Mem.  ii.  198. 


!208  INSECT   TRANSFORMATIONS. 

bis  Aurelian,  says,  that  the  caterpillar  of  the  Camber- 
well  beauty  {Vanessa  Antiopa),  which  feeds  grega- 
riously on  the  willow,  sometimes  defoliates  the  trees 
of  a  w  ole  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  f,  whose 
multitudinous  colonies  spread  great  alarm  over  the 
'country  in  the  summer  of  1782.  This  alarm  was  much 
increased  by  the  exaggeration  and  ignorant  details 
which  found  their  way  into  the  newspapers.  The  ac- 
tual numbers  of  these  caterpillars  must  have  been  im- 
mense, since  Curtis  says,  "  in  many  of  the  parishes 
near  London  subscriptions  have  been  opened,  and 
the  poor  people  employed  to  cut  off  the  webs|  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." 

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  "  were  the  usual  presage 
of  the  plague  ;"  and  others  that  they  not  only  pre- 
saged it,  but  would  actually  cause  it,  for  "  their 
nuuibers  were  great  enough  to  render  the  air  pesti- 
lential,'' 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. 

*  See  Insect  Architecture,  page  330,  for  a  figure  of  the  nest. 


RAVAGES   OF   CATERPILLARS.  209 

'*  ignorant  of  their  history,  was  under  the  greatest 
apprehensions  concerning  them  ;  so  that  even  prayers 
were  offered  up  in  some  churches  to  dehver  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  {PorthesiaChrysorrhcea),wih[ch,  inl731-2, 
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,  hke  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  shelter 
of  their  warm  nests*,  survived  the  winter  in  such 
numbers,  that  they  th/eatened  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  {dechejiiller)  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  %.  The  ignorance  displayed  in  France  at  the 
time  in  question  was  not  inferior  to  that  recorded  by 

*  See  Insect  Architecture,  p.  331,  for  a  figure. 
f  Reaumur,  ii.  p.  137.  J  Insect  Arcliilecture,  p.  329. 

N  3 


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  slin>e  of  snails,  which  they 
were  said  to  have  been  seen  collecting  for  the  pur- 
pose !  *'  Verily,"  exclaims  Reaumur,  "  there  is 
more  ignorance  in  our  asre  than  one  might  believe." 

It  is  justly  remarked  byCurtis,  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  j)roduce  a  famine  among  cattle. 
Curtis  says  it  is  found  on  the  "  hawthorn  most  plen- 
tifully, oak  the  same,  elm  very  plentifully,  most  fruit- 
trees  the  same,  blackthorn  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  alsc 
destroy  the  fruit  in  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  ditference  of  temperature  and  moisture  in  par- 
ticular seasons  may  produce  this  diversity. 

An  alarm,  similar  to  those  vve  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,  flit- 
ting 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, 
remaining  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  f.  At  least 
two  broods  seem  to  be  jjroduced  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  hot  heard  of  its  having  ever  been  so  destruc- 
tive here  as  in  France,  where,  as  usual,  the  most 
improbable  causes  were  assigned  for  its  increase. 
'*  In  some  places,"  says  Reaumur,  "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  super- 
natural agents,  however,  must  have  been  either  very 
numerous  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.  i  J.  R.  +  Reaumur,  ii.  336. 


212 


INSECT  TRANSFORMATIONS. 


that  they  were  poisonous  ;  and  many  were  in  conse- 
quence afraid  to  touch  soups  or  salads.  Reaumur 
tliought  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  containinp:  cater- 
pillars, and  yet  all  the  world  are  not  poisoned  thereby, 
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 
fertile,  would  produce  800,000,  a  number  much  more 
than  sufficient  to  effect  great  destruction  *.  Did 
not  Providence,  therefore,  put  causes  in  operation  to 


Transformations  of  the  y  moth  (Plusia  Gamma),    a.  the  agg, 
greatly  magnified,  on   a  morsel  of  leaf,      b,  the  egg;  on  a  leaf, 


natural  size. 


c,  the  larva.    <1,  the  pupa,    e,  the  moth. 
*  Reaumur,  ii,  337. 


RAVAGES    OF   CATERPILLARS.  213 

keep  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  vegetation. 

The  caterpillar  just  mentioned,  amongst  other  pot- 
herbs,  attacks  coleworts  and  cabbage ;  and  may 
sometimes  be  found  there  along  with  another,  not 
uncommon,  but  seldom  very  destructive,  called  by  col- 
lectors the  burnished  brass  (Pliisia  chrijsitis),  which 
differs  little  from  the  caterpillar  of  the  y  moth,  except 
in  being  of  a  brighter  green.  Another,  called  the  old 
g-entlewoman  {Mamestra  hrassicfE,  Treitsche),  is  so 
destructive  to  cabbages  in  Germany,  that  the  gar- 
deners g-ather  whole  baskets  full  and  bury  them  ; 
but  as  Rosel  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  cater- 
pillar, as  well  as  that  of  the  brown-eye  {Mamestra 
oleracea),  do  considerable  damage  in  Wiltshire,  but 
nothing  to  what  is  reported  of  it  in  Germany. 

The  leaves  of  cabbages,  cauliflower,  brocoli,  cole- 
I  worts,  and  turnips,  are  frequently  devoured  to  a 
more  considerable  extent  by  the  sub-gregarious  cater- 
pillars of  the  white  butterflies  (Poiitia  brassicce,  P. 
napi,  &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 
cultivated  plants  ;  for  we  have  seen,  near  Islington, 
the  oleraceous  weeds,  such  as  rape  (Braasica  napus)^ 
over-run  with  them  in  the  very  same  fields  with  cul- 
tivated cabbages,  which  were  not  touched  f;  so  that 
the  caterpillars  are  not  always  so  injurious  as  we 
might  at  first  suppose,  since  in  this  case  they  tend  to 
Rose),  Inseckten,  i.  iv.  170,  t  J.  R. 


214  INSECT    TRANSFORMATIONS. 

keep  clown  the  weeds,  while  the  birds  and  the 
ichneumon-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- 
tcBgi,  Stephens),  is  in  some  seasons  and  districts 
no  less  destructive  to  orchards  and  hawthorn  hedges 
than  the  preceding  ones  are  to  the  kitchen-garden. 
Salisbury,  who  wrote  at  Chelsea  in  1815,  says  it 
*'  commits  great  destruction  every  spring,  and  not 
only  to  the  apple-trees,  but  other  kinds  of  fruits*." 
Mr.  Stephens,  writing  in  1827,  says,  "  ia  June  1810, 
I  saw  it  in  plenty  at  Coombe  Wood,  and  in  the  fol- 
lowing year  J  captured  several  at  Muswell-hill,  since 
which  time  I  have  not  seen  any  at  large  f."  Mr. 
Haworth  also  says,  "  it  has  not  of  late  years  been 
seen  at  Chelsea,  where  it  formerly  abounded."  We 
have  never  met  \\'\i\\  it  at  all.  According  to  Salisbury 
the  female  butterfly  lays  her  eggs  near  the  extremity 
of  an  oid  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.  ''  In  this  state,"  he  adds,  "  we 
have  instances  of  their  remaining  without  losing  their 
vitality  for  several  years,  until  a  favourable  opportu- 
nity of  their  being  brought  into  existence  arrives  |.'* 
The  caterpillars,  which  are  at  first  black  and  hairy, 
live  in  common  in  a  silken  tent.  They  become  sub- 
sequently 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 
fiequently  despoiled  of  their  leaves,  both  by  the 
speckled  caterpillar  of  the  magpie-moth  (^Ahraxaa 
grossulariata),   and  by   what    Reaumur    terms    the 

♦  Hints  on  Orchards,  p.  56.         f  Illustrations,  i.  Haustellala,  27. 
X  Hints  on  Orcliards,  p.  57. 


i, 


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  goose- 
berry saw-fly  does  not,  like  some  of  the  family,  cut  a 
groove  in  the  branch  to  deposit  her  eggs ; — "  of 
what  use,  then,"  asks  Re'aumur,  "  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 
perambulated  the  leaves  in  search  of  a  place  suited  to 
her  purpose,  and,  passing  under  a  leaf,  began  to  lay. 


aaa.  Saw-fly  of  the  gooseberry  (iVt'ffJo^ui  Ribesii,  Stephens). 
h,  its  eggs  on  the  nervuresof  a  leaf,  dd,  the  caterpillars  eating, 
c,  one  rolled  up.    /,  one  extended. 


*  See  Insect  Architecture, 
curious  instrument 


ch; 


for  a  description  of  this 


til6  INSECT   TRANSFORMATIONS. 

depositing  six  e^gs  within  a  quarter  of  an  hon;?. 
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  tirmly, 
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 
tlu'ust  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 
pro-legs,  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  {NeTuatits  CapretP, 
Stephens)  frequently  becomes  extensively  destruc- 
tive to  several  sj)ecies  of  willow,  sallow,  and  osier. 
It  is  so  like  that  of  the  gooseberry,  and  that  of  the 
willow  (NeTnalus  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  os,\er  {Salijc  vitellind),  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,  ".  125. 


RAVAGES  OF  CATERPILLARS. 


217 


During  the  three  last  summers,  we  also  remarked 
that  the  alders  {Almis  glutinosa)  along  the  banks  of 
the  Kavensbourne,  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  Reaumurt  {Selandria 
Alni?  Stephens). 


a,  Nematus  caprece,  on  the  osier ;  h,  Selandria  alni  ?  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.  t  Reaumur  vol.  v.,  pi.  11,  fig   1,  2. 

O 


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  writ- 
ten 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  {Nedyiis  contractus, 
Stephens),  a  no  less  formidable  depredator  some- 
times appears  in  a  caterpillar  belonging  to  the  saw- 
ily  family  {Tenthredinidce)^  and  apparently  of  the 
genus  Athalia.  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  beach  and  the  clitfs,  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.f 

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. 
t  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  v;hen,  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  tropical 
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.  Mayshall,  that  whole  districts 
were  ravaged  by  them, — the  descendants,  of  course, 
in  the  second  generation,  of  the  saw-flies  which 
perished  on  the  beach  and  at  sea  the  preceding  au- 
tumn. 

Some  caterpillars,  which  either  conceal  themselves 
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  re- 
specting mysterious  blights.  In  this  manner  will  the 
caterpillars  of  the  ghost-moth  {Hepialus  Hiimuli) 
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  wiiher,  giving  good  cause  to  surmise, 
except  in  the  leaves  not  being  brown   or  parched, 

o2 


220  INSECT  TRANSFORMATIONS. 

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  (Mgeriatipu/ifomiis,  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  projectiug  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. f 
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  de- 
stroy willow,  poplar,  and  oak-trees,  of  considerable 
magnitude;  but  the   mother-moth   seems   to   prefer 
laying  her  eggs  upon  those  which  have  already  be- 
gun 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  cater- 
pillars of  the  clear  underwing  {Algeria  asiliformis, 
Stephens),  without  seeming  to  have  its  growth  at  all 
retarded.]: 

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, 
LiNN^us),  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  caterpillar, 
which  is  smooth  and  white,  ties  together  with  silk 
several  grains  of  wheat,  barley,  rye,  or  oats,  weaving 


*  J.  R.  f  Kirby  and  Spence,  vol.  i.  p.  197. 

X  See  Ins.  Archit.,  p.  192. 


ii 


■RAVAGES  OF  CATERPILLARS. 


221 


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  be- 
ginning of  July  that  the  moths,  which  are  of  a  silvery 
grey,  spotted  with  brown,  appear  and  lay  their  eggs 
in  granaries. 

The  caterpillar  of  another  still  more  singular  grain- 
moth  (Tinea  Hordei^  Kirby)  proves  sometimes  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  sanguinary  wars  must 
sometimes  arise,  in  cases  of  preuccupancy,  a  single 
grain  of  barley  being  a  rich  heritage  for  one  of  these 


Transformations  of  the  grain  moths,  a,  grain  of  barley  includ- 
ing a  caterpillar  •,  h,  c,  the  grain  cut  across,  seen  to  be  hollowed 
out  and  divided  by  a  partition  of  silk  ;  rf,  the  moth  {Tinea  Hor- 
dei)  ;  e,  grains  of  wheat  tied  together  by  the  caterpillar,/,-  g,  the 
moth  {Euplucamus  granelld)- 


222  INSECT  TRANSFORMATIONS. 

tiny  insects ;  but  he  confesses  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  hollow  grain,  and  changes  to  a 
pupa  in  November.t 

Two  other  caterpillars  of  a  different  family,  the 
honeycomb-moth  {Galleria  cereana^  Fabi?.),  and  the 
honey-moth  {G.  alvearia^  Fabr.),  the  first  having 
square,  and  the  second  rounded  wings,J  do  very  con- 
siderable 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  Swammer- 
dam,  never  attack  them,  nor  prevent  their  entrance 
into  the  hives,  unless  they  chance  to  brush  against 
them  in  their  passage.  But  Reaumur  actually  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  Key  says,  at  the  entrance 
of  the  hive  :  this  writer  adds,  "  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  Swammerdam,  "  gnaws  round  holes 
through  the  waxen  cells,  one  caterpillar  sometimes 
breaking   open   and  destroying  fifty  or    sixty  cells. 

*  See  Insect  Architecture,  p.  231. 

f  Reaumur,  Mem.,  vol.  ii.  p.  186,  &c. 

X  Stephens's  Catalogue,  vol.  ii.  p.  213. 

^  Keys,  Treatise  on  Bees.  p.  178,  edit.  1814. 


RAVAGES  OF  CATEKPILLARS. 


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, 
"  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-motlis.  a,  a,  n.  Galleries  of 
the  cell-borinj?  caterpillar  ;  b,  the  female  ;  c,  the  male  moth  {Gal- 
Icria  alvearia)  ;  rf,  d,  d,d,  galleries  of  the  wax-eating  caterpillar  ; 
e,  seen  at  the  entrance  ;  //the  same  exposed  ;  g,  its  cocoon  ;  /i.the 
moth  (Gallcria  cereana). 


224  IXSFX'T  TRANSFORMATIONS. 

there,  cover  up  these  pupje  with  its  excrements,  so 
that  they  could  scarcely  be  known."  He  adds  with 
great  naivete,  "  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  pupae  which  I  had  designed  to  observe  in  their 
changes."* 

M.  Bazin,  a  friend  of  Reaumur,  discovered  the 
caterpillar  of  a  moth  of  this  order  feeding  on  choco- 
late, of  which  it  seemed  very  choice,  always  prefer- 
ring that  which  had  the  finest  flavour.  The  moth  is 
sometimes  produced  in  September,  and  sometimes  in 
the  beginning  of  the  following  summer.  It  is  pro- 
bable that,  like  the  cheese-fly,  it  might,  in  default  of 
chocolate,  select  some  other  aliment. t 

*  Swammerdam,  vol.  i.  p.  225.     f  Reaumur,  vol.  iii.  p.  277. 


(   225   ) 


Chapter  IX. 

Voracity  of  Caterpillars,  Grubs,  and  Maggots — continued. 

Grubs. 

We  frequently  hear  farmers  and  gardeners  complain- 
ing that  their  produce  is  destroyed  by  "  the  grub;" 
they  might  with  equal  propriety  accuse  "  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  indi- 
cate, we  are  far  under  the  mark  in  reckoning  a  thou- 
sand 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  for- 
tunately not  abundant  in  the  north.  We  only  once 
met  with  the  cockchafer  in  Scotland,  at  Sorn,  iii  Ayr- 
shire.f  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  Dulvvich  and  Camberwell 

*  Ririgley,  /^uim.  Siog.  vol.  iii.  p.  230.  f  -T-  R- 

o  3 


226  I.N  SECT  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  increased  remarkably  in  size.  In  the  fol- 
lowing May  they  fed  so  voraciously  that  they  required 
a  fresh  turf  every  second  day  ;  and  even  this  provmg 
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  manner  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 
prevented  from  going  deep  enough,  it  shows  great 
imeasiness  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  {MtJulontha  vulgaris^,  a, 
newly-hatch<>d  larva;  h,  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,     h,  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  sod,  and  devour- 
ing the  roots  of  grass  and  other  plants  ;  so  that  the 


228  INSECT  TKANSFORMATIONS. 

turf  may  easily  be  rolled  off,  as  if  cut  by  a  turfing- 
spade,  while  the  soil  underneath,  for  an  inch  or  more, 
is  turned  into  soft  mould  liUe  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. "t  In  the  year  1785,  a  farmer,  near  Blois 
in  France,  employed  a  number  of  children  and  poor 
persons  to  destroy  the  cockchafers  at  the  rate  of  two 
liards  a  hundred,  and  in  a  few  days  they  collected 
fourteen  thousand. | 

"  I  remember,"  says  Salisbury,  "  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  awraia),  which  feeds  on  the  roots 
of  trees. 

The  grub  of  an  allied  genus,  the  midsummer- 
chafer  (Zantheumia  Solstitialis,  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. 

*  Phllosoph.  Trans,  xliv.  579.         f  Aiiim.  Biog.  iii.  233. 
'^  Anderson's  Recr.  ill  Aj^aicult.  iii.  120.  §  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  w  hen  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. f  The  grubs  of  the  click- 
beetles,  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-j  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  })astures,  unless  in  fields  recently 
laid  down  with  grass.  "  The  wire-worm,"  says 
Spence,  "  is  particularly  destructive  for  a  few  years 

*  See  the  Harleian  Dairy  System,  p  222. 

t  S(^e  Loudon's  Encycl.  of  Agricult.  §  6921. 

J  Act.  Holm.  1770,  p.  284.      5  Kiiby  and  Spence,  i.  182. 


230  INSECT  TIIAXSFORMATIONS. 

Ill  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- 
stroyed.*" 

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  nociilucus,  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. t 

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 

*  Iiitr.  i.  182-3.  t  Gt'og.  des  Plaiites,  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  {Staphylimdo'  ?),  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,  imagined 
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  fur- 
ther 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  re- 
mark, that  along  with  these  grubs  were   found  those 


a,  Zabrus  gibbus ;  b,  Meloloutha  ruticoniis. 
="  Linn.  Trans.  Ix.  156-61. 


232  INSECT  TRANSFORMATIONS. 

of  a  chafer  (Melolontha  rujicornis,  Fabr.),  in  the  pro- 
portion of  about  a  fourth.* 

To  this  accouut  Mr.  Stephens  appends  the  shrewd 
questions — "  May  not  these  herbivorous  larvae  [of 
the  chafer]  have  been  the  principal  cause  of  mischief 
to  the  wheat,  while  those  of  the  Zabrus  rather  con- 
tributed to  lessen  their  numbers,  than  to  destroy  the 
corn  ?  And  is  it  not  probable  that  the  perfect  in- 
sects 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 
highly  important,  for  the  interests  of  the  agricul- 
turist in  those  districts  where  the  insect  abounds, 
that  the  question  should  be  thoroughly  set  at  rest; 
because,  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. "f 

We  have  little  doubt  that  Mr.  Stephens  is  right, 
and  Germar  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 {Adephaga,  Clairville)  are  not  herbivorous, 
but  carnivorous. J  Similar  errors  will  come  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. 

f  Stephens,  Illusfrations,  i.  Mandib.  pp.  4  and  140. 
I  See  an  Illustration  in  Insect  Architect.,  p.  207-8. 


RAVAGES  OF  GRUBS.  233 

beetles  and  weevils.  Among  the  first,  the  gnawing 
beetles  {Bruchidce,  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  Swe- 
den, 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  men- 
tioned 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. f  The  insect 
most  destructive  to  our  peas  is  the  pulse-beetle 
(Bruchus  granarius^  Ltnn.),  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 
{Apion,  Herbst),  known  by  the  yellow  colour  of 
their  thighs  or  their  feet ;  and  when  the  farmer  ex- 
pects 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. 

f  Amoroux,  Insectes  Veuimeux,  288.  Kirbv  and  Spence, 
i.  177. 


234  INSECT  TRANSl'OKMATIONS. 

called  by  the  French  cadelle  {Trogonta  mauritanica, 
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  {Calandria  granaria, 
Clairville),  the  same,  probably,  which  is  mentioned 
by  Virgil, 

.  Populatque  ingentem  farria  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  descend- 
ants; and  they  were  told  by  an  extensive  brewer 
that  he  had  collected  and  destroyed  them  by  bushels,t 
— meaning,  no  doubt,  insects  and  damaged  grain 
together. 


Corn-weevil  {Calandria  grunaria),  magnified. 

Another  beetle  grub,  popularly  called  the  meal- 
worm, the  larva  of  Tenehrio  moiitor,  Linn.,  which 
lives  in  that  state  two  years,  does  no  little  damage  to 
flour,  as  well  as  to  bread,  cakes,  biscuits,  and  similar 
articles.  Accounts  are  also  given  of  the  ravages 
committed  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.  Sparrraan  tells  us,  that  he  has 
witnessed  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  spoon- 
ful of  the  soup.  In  the  case  of  soup,  or  of  other 
food  which  has  been  exposed  to  heat,  the  only  in- 
convenience is  the  disgust  which  must  ensue ;  but, 
unfortunately,  there  may  sometimes  occur  circum- 
stances 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  effect- 
ually than  a  statement  of  facts  well  ascertained. 
"  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  dis- 
orders 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  iVoiu  it. 
*  Spectacle  de  la  Nature,  i.  65. 


236 


IJ^SECT  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  caterpillar 
of  the  tabby-moth  (yl^/o^^a  pinguinalis^  Latreille), 
which  feeds  on  butter,  the  leather  on  book-boards, 
&c.,  is  said,  on  the  authority  of  Linnseus,  to  get 
sometimes  into  the  stomach,  and  to  produce  con- 
siderable disorder  ;*  but  this  insect  is  very  common 
in  houses,t  and,  from  the  rarity  of  such  accidents, 
we  are  led  to  doubt  the  evidence  usually  brought  for- 
ward. In  this  case  we  are  the  more  induced  to 
question  the  authority  of  Linnaeus,  from  his  having 
made  an  evident  mistake  in  a  similar  case  respecting 
intestinal  worms. 


Transformations  of  the  tabby-moth  (Aglossa  pingmnalix').  a,  the 
caterpillar  feeding?  on  butter  ;  b,  c,  d,  feeding  on  leather  under  <,'al- 
lenes ;  e,  the  muth  with  the  down  rubbed  oft" ;  /,  the  same  perlect. 

Linnaeus  afiSrms,  that  in  the  presence  of  seven  of 
his  companions  he  discovered,  near  Reuterholm,  in 
Dalecarlia,  a  tape- worm  in  acidulous  ochre  (jOchram 
acidularem),  at  which  he  marvelled  the  more  since 

"■  Linnaeus,  quoted  by  Kirby  and  Spence,  i.  136. 
t  L;itreille,  Hist.  Gcnerale,  xiv.  229. 


INTESTINAL  WORMS.  237 

acidulous  water  of  this  kind  had  been  drunk  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  intestinal  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 
Linnaeus  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  (Nais),  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  em- 
pire ;  since  there  are  few  individuals  who  are  not 
affected  with  these  worms  at  some  period  of  their 
lives.  According  to  our  experiments,  the  nais  ceases 
to  exist  in  a  temperature  considerably  less  than  that 
of  the  human  body;  besides,  as  it  lives  on  minute 
fresh-water  moUuscse,  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 
"  minute  insects  flying  in  the  air;"]:  for,  if  so,  the 

*  Linnaeus,  quoted  by  Bonnet,  CEuvres,  iii.  137.         f  J.  R. 
t   Frank.  De  Curand.  Homin.  Morb.  lib.  vi. 


238  INSECT  TRANSFORMATIONS. 

worms  would  naturally  produce  similar  insects  to  theii? 
parents ;  whereas  they  are  either  oviparous,  as  Goetze 
affirms,  or,  as  Bremser  thinks,  ovo-viparous  ;*  both 
agreeing  that  they  are  not  transformed  into  flying  in- 
sects. Reaumur  made  the  more  plausible  conjecture, 
that  they  might  be  introduced  by  eating  tench  and 
other  fish,  in  which  they  are  known  to  abound  ;t  but, 
independently  of  their  being  destroyed  by  heat  in 
cooking,  this  has  been  subsequently  disproved  by  ex- 
periment ;  for  M.  Deslonchamps  says,  that  "  when 
animals  are  fed  for  some  time  on  intestinal  worms 
{Entoozaria)  alone,  and  then  killed,  they  are  not 
found  infested  with  these  worms. "|  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  *'  the  march  of  nature  in 
the  production  of  all  living  beings  !  ''§  This  indefinite 
doctrine  is  also  held  by  Geoft'roi  St.  Hilaire,  Cuvier, 
Blumenbach,  and  other  distinguished  living  natural- 
ists ;  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  doubtful  facts. 

It  may  not  be  unmteresting  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. II     Some  of  the  more  singular  species 

*  Bremser,  Uber  Lebende  Wiirmer  in  leb.  Mensch, 

I  Letter  to  Bonnet,  CEuvres,  vol.  iil.  p.  344. 

\  Diet.  Classique,  vol.  viii.  p.  589. 

§  Anim.  sans  Vertebres,  vol.  i.  p.  15. 

|l  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,  introduced 
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  medical  men 
and  competent  naturalists;  and  is  published  in  the 
Dublin  Transactions,  by  Dr.  Pickells,  of  Cork.f 
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  morn- 
ing of  a  winter's  day,  and  having  been  exposed  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  would  drink 

*  See  Good's  Nosologia,  Helminthia  Alvi ;  and  Study  of 
Med.,  vol.  i.  p.  336. 

f  Trans,  of  Assoc.  Phys.  in  Ireland,  iv.  vii.  and  v.,  p.  177, 
8vo.  Dublin,  1824-1828. 


240  INSECT  TRANSFORMATIONS. 

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.     Following  this  absurd 
and  disgusting  prescription,  she  took  from  time  to  time  i 
large  quantities  of  the  draught ;  some  time  afterwards,  ] 
being  affected  with  a  burning  pain  in  the  stomach 
{CarcHalgia),  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  in- 
credible numbers  of  grubs  and  maggots,  chiefly  of 
the  churchyard  beetle  {Blaps  mortisaga,  Fabr.). 
"  Of  the  larvae  of  the  beetle,"  says  Dr.  Pickells,  *'  I 
am  sure  I  considerably  underrate,  when  1  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 
immediately  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  molitor), 
I  saw  myself  thrown  up  at  different  times.  The 
average  size  was  about  an  inch  and  a  half  in  length, 
and  four  lines  and  a  half  in  girth.  The  larvae  of  the 
dipterous  insect,  though  voided  only  about  seven  or 
eight  times,  according  to  her  account,  came  up  almost 
literally  in  myriads.  They  were  alive  and  moving." 
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,"  &c. 


INTESTINAL  GRUBS  AND  BEETLES.         241 

larvge  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 
larvse  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  spirits  of  wine,  so  fatal  to  most  insects,  but 
it  revived,  even  after  being  immersed  a  whole  night, 
and  afterwards  lived  three  years. t 


Churchyard-beetle  (Blaps  mortisaga)  in  the  ^ub  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  not  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. 
t  Philosoph.  Trans.,  No.  457. 

P 


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, 
Germar)  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  depositmg  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  eg^ ;  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 

*  Bmgley,  Animal  Biography,  vol.  iii.  p.  25). 


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  ver^'- 
soft  it  no  doubt  stretches  itself  out  for  the  purpose, 
using  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  pupse  till  the  follow- 
ing 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  Slbert-tree. 
a,  e<,'g  hole  in  the  nut ;  b,  exit  hole  of  the  grub.  B,  the  larvae  of 
the  nut-beetle.  C,  the  same  in  the  pupa  state.  D,  female  beetle- 
E,  male  beetle,  c,  the  bee'le  that  destroys  the  bloom-bud  of  the 
apple-tree ;  a,  the  same  in  the  larva  state ;  b,  the  chrysalis  of  the 
same. 

"  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 
tlie  spring,  these  hutch,  and  the  grubs  feed  on  the 


244  INSECT  TRANSFOIIMATIONS. 

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  re- 
newed, 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."*  Sahsbury's 
weevil  is  probably  the  Anthonomus  Ponwritm  of  Ger- 
mar;  and  Knight's  his  Polydrusus  Mali.  Another 
weevil  {Rhynchiies  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  sycophania^ 
Weber),  which  is  rare  in  Britain.  It  is  sometimes 
found  in  the  nests  of  the  processionary  and  other  gre- 
garious caterpillars,  so  gorged  with  those  it  has  de- 
voured that  it  can  scarcely  move  without  bursting. 
Not  contented  with  this  prey  alone,  however,  the 
younger  grubs  are  said  "  often  to  take  advantage  of 
the  helpless  inactivity  into  which  the  gluttony  of 
their  maturer  comrades  has  thrown  them,  and  from 
mere  wauLonness,  it  should  seem,  when  in  no  need  of 
other  food,  pierce  and  devour  them."t  It  is  a  fami- 
liar occurrence  to  those  who  breed  insects  to  find 
caterpillars,  whose  natural  food  is  leaves,  devouring 
others  in  the  same  nurse-box ;  and  without  any  ap- 

*  Salisbury's  Hints  on  Orchards,  p.  92. 
f  Kirby  and  Spence,  vol.  i.  p.  277. 


RAVAGES  OF  BEETLES.  245 

parent  discrimination  whether  these  are  tlie  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  {Scolitor 
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 
under  cover.  They  dig,  therefore,  long  tubular  gal- 
leries 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  always 
in  a  right  line,  yet,  however  near  they  may  approach 
to  the  contiguous  ones,  none  of  them  ever  break  into 


Bark  mined  in  rays  by  beetle-grubs. 
*  J.  R.     See  also  De  Geer,  i.  533,  &c.,  and  Reaumur,  ii.  413, 

r3 


246  INSECT  TRANSFORMATIONS. 

each  otlier's  premises.  We  cannot  but  admire  the 
remarkable  instinct  implanted  in  those  grubs  by  their 
Creator  ;  which  guides  them  thus  in  lines  diverging 
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 
larvae  of  the  locust  {Locusta  migratoria.  Leach), — 
the  scourge  of  oriental  countries.  *'  A  fire  devoureth 
before  them,"  says  the  prophet  Joel,  "  and  behind 
them  a  flame  burneth  :  the  land  is  as  the  garden  of 
Eden  before  them,  and  behind  them  a  desolate  wil- 
derness ;  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  moun- 
tains 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 ;  nei- 
ther 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  de- 
jiosit  their  eggs.  "  These  were  no  sooner  hatched 
in  June,"  he  continues,  "  than  each  of  the  broods 
collected  itself  into  a  compact  body,  of  a  furlong  or 
more  in  square ;  and  marching  afterwards  directly 

•  Jcel  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  trenches 
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. 

"  A  day  or  tw^o  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  en- 
tirely dispersed."* 

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.  Bar- 
row. In  the  part  of  the  country  where  he  was,  the 
*  Shaw's  Travels,  p.  287. 


248  INSECT  TRANSFORMATIONS. 

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  car- 
cases 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 
attack  a  field  of  corn  just  come  into  ear,  they  first, 
according  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  march  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 
discontinued,  when  the  troop  divides  into  companies 
that  surround  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  farm- 
ers have  any  chance  of  destroying  them ;  this  they 
sometimes  effect  by  driving  among  them  a  flock  of 
two  or  three  thousand  sheep,  by  whose  lestiessness 
great  numbers  of  them  are  trampled  to  death.  The 
year  1797  was  the  third  of  their  continuance  in  Sneuw- 
berg  ;  and  their  increase  had  been  more  than  a  mil- 
lion-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  hun- 
dred 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 
uniformly  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  observ- 
ing 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,  "t 

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  ditFerent  places  ;  and  they 
afterwards  spread  themselves  over  Poland  and  Lithu- 
ania in  such  astonishing  multitudes  that  the  air 
was  darkened,  and  the  earth  covered  with  their  num- 
bers. Id  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. 
•f  Irby  and  Mangles'  Travels  in  Eg^ypt  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  consider- 
able part  of  Italy,  and  being  at  last  cast  into  the  sea 
(as  seems  for  the  most  part  to  be  their  fate),  a  pesti- 
lence, it  is  alleged,  arose  from  the  stench,  which  car- 
ried 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.f 

*  Bingley,  Anim.  Biog.  iii.  280. 
t  MouflCet,  Theatr.  Insect.,  123. 


Locust. 


(   252   ) 


Chapter  X. 

Voracity  of  Caterpillars,  Grubs,  and  Maggots — concluded. 

Maggots. 

Adhering  to  the  distinction  of  terming  those  larvaB 
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  larvaj  of  one  or 
two  common  species  of  crane-flies  {TipulidcB),  well 
known  by  the  provincial  names  of  father-long-legs, 
Jenny-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  employing  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  sometimes 
in  the  tilled  ground  of  gardens  and  farms.  For  this 
purpose  the  female  is  provided  with  an  ovipositor  well 
adapted  to  the  operation,  consisting  of  a  sort  of  pin- 
cers 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  Svqueezed  out  of  a  ripe  cherry,  as 
in  the  following  figure. 

*  See  Stick iiey^s  Observ.  on  the  Grub,  8\'0.  Hull,  1800. 


i: 


MAGGOTS  OF  CRANE-FLIES.  253 


Ovipositor  and  eggs  of  the  crane-fly  (Ttptila). 

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  another  place, 
but  without  bringing  herself  into  a  horizontal  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  nourish- 
ment. 

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 

Q 


254  INSECT  TRANSFORMATIONS. 

grass  and  everything    green,  as  if  the  turf  had  been 
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  sub- 
sist.    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  very  complete,  however,  was  their  destruction  of  . 
the  roots  on  the  spot  in   question,  that  even  now,  at   1 
the  distance  of  two  years,  it  is  still  visibly  thinner  of  J 
herbage  than  the  parts  around  it.* 

Rt^aumur  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.  Reaumer, 
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.f  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  (^Ctenophora  Jiaveolatay 
Meigen),  which  is  very  rare  in  Britain.  It  is  proper 
to  mention,  however,  that  Mr.  Stickney's  experi- 
ments,! contrary  to  the  conclusions  of  Reaumer, 
indicate  that  these  larvae  devour  the  roots  of  grass ; 
and  Stewart  says  they  "  feed  on  the  roots  of  plants. 


J.  R.  f  Reaumer,  v.  12,  &c. 

1   Obs.  oil  Hip  Grub. 


RAVAGES  OF  MAGGOTS.  255 

corn,  and  grasses,  and  are  thence  destructive  to  gar- 
dens, 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- 
stroyed by  them,  being  rendered  as  completely  brown 
as  if  they  had  suffered  a  three  months'  drought,  and 
destitute  of  all  vegetation  except  a  few  thistles.  A 
square  foot  of  the  dead  turf  being  dug  up,  210  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."t 

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  {Cecidomyia 
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  (Culicoides 
punctata^  Latr.),  of  an  orange  colour,  and  wings 

*  Elements,  ii.  267.  f  Intr.  i.  318,  note. 

q2 


256  INSECT  TRANSFORMATIONS. 

rounded  at  the  tip,  and  fringed  with  hairs.*  The 
female  is  furnished  with  a  retractile  ovipositor,  four 
times  as  long  as  her  body,  and  as  fine  as  a  hair,  for 
depositing  her  eggs,  Nvhich  she  does  in  the  glumes  of 
the  florets  of  the  grain.  The  following  account  of  its 
proceedings  is  given  by  Mr.  ShirefF,  an  intelligent 
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. 
The  eggs  were  visible  on  the  23rd,  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. 

"  The  flies  were  observed  to  frequent  the  wheat- 
plant,  including  the  thick-rooted  couch-grass  (Tnti- 
cum  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  shim  that  which  is 
deficient  in  foliage. 

"  The  flies  almost   invariably  preferred   the   ears 
emerging  from  the  vagina  to  those  further  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 
*  Linn.  Trans.,  iii.  213  ;  iv.  234-240  :  v.  96. 


.  RAVAGES  OF  MAGGOTS.  257 

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 
furnished. 

"The  fly  deposits  its  eggs  with  much  intensity, 
and  may  easily  be  taken  when  so  employed.  Upon 
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  deposit  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. 

"  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  chafi'.  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  larvas  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  conveyance  from  the  larvae  to  the  style, 
but  also  food  for  their  support.  The  anthers  are 
prevented  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 


258 


INSECT  TRANSFORMATIONS. 


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  gumming  down  the  anthers,  many  of  the  flies  are 
entangled  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 
and  a  grain,  which  is  generally  shrivelled,  as  if  de- 
prived of  nourishment ;  and  although  the  pollen  may 


Germination  of  a  grain  of  wheat,  n,  the  heart  of  tlie  grain,  the 
part  devoured  by  the  insect,  h,  bag  of  the  seed,  c,  the  root,  d, 
vessels  to  convey  the  uutvimeut  for  the  root,  e,  feathers  conveying 
tlie  pollen  to  fructify  the  seed. 


RAVAGES  OF  MAGGOTS.  259 

furnish  the  larvse  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,"* 

Another  intelhgent  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.f 


Transforniations  of  the  wheat-fly.  a,  the  female  fly  magnified  ; 
h,  larvas,  natural  size,feeding  ;  c,  one  magnified. 

'  It  is  interesting  to  learn  that  this  destructive  in- 
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  (Plafy- 
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  tivo  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  vipon  her  vic- 
tim, and  intensely  vibrating  her  antennae,  and  bending 
herself  obliquely,  plunged  her  ovipositor  into  the  body 

*  Loudon's  Mag.  of  Nat.  Hist.,  Nov.  1829,  p.  450. 
t  Ibid.  September,  1829,  p.  324. 


260  INSECT  TRANSFORMATIOiXS. 

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  eg^  in  each.  Nay,  when 
she  examined  one  which  she  fomid  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  successively  presented  to  an  earwig, 
which  devoured  them  immediately.''^  Mr.  Gorrie 
describes  these  ichneumons  as  appearing  in  myriads 
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.  Markwick,  an  intelligent  naturalist,  by 
a  series  of  observations  on  a  British  fly  {Chlorops 
pumilionisy  Meigen)  which  attacks  the  stems  of 
wheat,  created  no  little  alarm  among  agriculturists. 
Markwick's  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  larvae  in  a  small  tlower-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  aff"ected 
by  It: 

*  Linn,  Trans,  ut  supra.         f  Loudon's  Ma<^.  nt  supra. 
\  Mag.  Nat.  Hist.,  July  1829,  p.  292. 


WHEAT-FLIES.  261 


a.  The  Hessian-fly  (Cecidomyia  destructor) ;  b,  Markwick  -fly 
(jChlorops  pumilionis)  magnilied. 

It  now  appears  that  Markwick  was  altogether  mis- 
taken in  identifying  his  insect  with  the  Hessian-fly 
{Cecidomyia  destructor,  Say),  which  has  been  accu- 
rately described  by  Mr.  Say  in  the  ''  Journal  of  the 
Academy  of  Natural  Sciences  of  Philadelphia  "  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  not  travel  more  than  seven  miles  annually,  and 
did  little  serious  damage  before  1788.  Their  num- 
bers seem  almost  incredible.  The  houses  in  the 
*  Mag.  Nat.  Hist.,  vol.  i.  p.  228. 

q3 


262  INSECT  TRANSFORMATIONS. 

infested  districts  swarmed  with  them  to  so  great  a 
degree,  that  every  vessel  was  filled  with  them ;  five 
hmidred  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- 
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.t 

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.  J 

Those  who  have,  from  popular  associations,  been 
accustomed  to  look  with  disgust  at  the  little  white 

*  Kirby  and  Spence,  vol.  i.  p.  172. 
f  Young,  Annals  of  Aa;ric.,  vol  xi, 
I  Journ.  of  Acad.  Philadelpli.  tit  supra. 


CHEESE-FLY.  263 

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  contrived  with  so 
much  art  and  design,  that  it  is  impossible  not  to  ac- 
knowledge them  to  be  the  work  of  infinite  power  and 
wisdom,  from  which  nothing  is  hid,  and  to  which 
nothing  is  impossible."*  But  whoever  will  examine 
it  with  care,  will  find  that  Swammerdam  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, 
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. 
"  I  have  seen  them  myself,"  says  Swammerdam, 
*' 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  afterwards  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  crumble  the  substance 
of  it  into  small  particles,  and  also  moisten  it  with 
some  sort  of  liquid,  so  that  the  decayed  part  rapidly 

*  Bibl.  Naturae,  vol.  ii.  p.  63. 


264 


INSECT  TRANSFORMATIONS. 


spreads.  I  once  observed  a  cheese  which  I  had 
purposely  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  and  entire."* 

The  cheese-hopper  is  furnished  with  two  homy 
claw-shaped  mandibles,  which  it  uses  both  for  digging 
into  the  cheese  and  for  movnig  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  furnished  with  two  wort- 
like  projections,  to  enable  it  to  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  ob- 
long form,  it  throws  itself  with  a  jerk  into  a  straight 
line,  and  thus  makes  the  leap. 


Cheese-hoppers  (Pinphila  casei.  Fallen),  a,  the  maggot  ex- 
tended ;  6,  iti  a  leaping  position  ;  d,  the  same  magnified  ;  e,  the 
fly  magnihed  ;  /,  ^f,  the  fly,  natural  size. 

One  very  surprising    provision    is  remarkable    in 
the  breathing-tubes  of  the  cheese-maggot,  which  are 
'^'  Swammerdam,  vol.  ii.  p.  69.     f  Bibl.  Nat-,  vol.  ii.  p.  65. 


CHEESE  MAGGOTS.  265 

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  men- 
tioned, 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  riot  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 
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 
display  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  larvae. 
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  domestica)  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 


266  INSECT  TRANSFORMATIONS. 

be  primarily  directed,  rather  than  having  recourse  to 
fly-waters. 

Another  common  insect  (Bibiohortulanus,  Meigen) 
lives  in  the  larvae  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  larvae  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  intro- 
duced this  insect  here,  however,  chiefly  for  the  pur- 
pose 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 
every  blossom. t  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  j  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. t  We  are  satisfied,  by  repeated  observation, 
that  the  fly  only  uses  its  sucker  (haustellunt)  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.$ 

*  Swammerdam,  x.  212.  f  Rail  Hist.  Insect,,  Pref.,  p.  xi, 

X  Reaumur,  v.  56.         ^  J.  R. 


BIBIO  HORTULANUS. 


267 


Transformations  of  Bibio  hortulanm,  Meiqen.  a,  the  egg  mag- 
nified ;  h,  the  same  when  hatched  ;  c,  d,  the  maggot  and  pupa 
magnified;  e,f,  the  same,  natural  size;  g,  the  fly. 

In  the  case  of  the  blow-flies,  Linnaeus  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 
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  "  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  parish  workhouse,  was  in  the  habit  of 
strolling  about  the  neighbouring  villages,  subsisting  on 


268  INSECT  TRANSFORMATIONS. 

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- 
ing 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  surgeon,  he 
presented  a  slight  loathsome  in  the  extreme ;  white 
maggots  of  enormous  size  were  crawling  in  and  upon 
his  body,  which  they  had  most  shockingly  mangled, 
and  the  removal  of  the  external  ones  served  only  to 
render  the  sight  more  horrid."  Kirby  adds,  "  in 
passing  through  this  parish  last  spring,  I  inquired  of 
the  mail-coachman  whether  he  had  heard  this 
story  ;  and  he  said  the  fact  was  well  known."*  The 
year  in  which  this  remarkable  circumstance  occurred 
is  not  mentioned. 

The  importance  of  the  insects  just  mentioned,  in 

*  lutr.,  i.  140,  and  note. 


UTILITY  OF  INSECTS.  269 

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  {Aphides) 
which  do  so  much  damage  to  cltivated  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."* 
The  truth  is,  however,  that  all  the  species  of  lady- 
birds {Coccinellidce,  Latr.),  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  scptempundata) ,  whose  larva  is  of 
considerable  size,  and,  of  course,  when  abundant, 
must  destroy  a  vast  number  of  aphides. 

The  maggots  of  many  species  of  a  beautifiil  family 
(SyrphidfS,  Leach)  of  two-winged  flies  are  also 
voracious  devourers  of  the  aphides.  These  larvss  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, 

*  Mag.  of  Nat.  Hist.,  i.  191. 


270 


INSECT  TRANSFORMATIONS. 


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, 
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  astonish- 
ing. It  was  but  last  week  that  I  observed  the  top 
of  every  young  shoot  of  the  currant-trees  in  my  gar- 
den curled  up  by  myriads  of  these  insects.  On  ex- 
amining them  this  day,  not  an  individual  remained  ; 
but  beneath  each  leaf  are  three  or  four  full-fed  larvae 
of  aphidivorous  flies,  surrounded  with  heaps  of  the 
skins  of  the  slain,  the  trophies  of  their  successful  war- 
fare."* 

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  some- 
what crescent-shaped,  and,  like  those  of  the  ant-lion. 


a,  Lace-wiuged  fly ;  h,  the  gnib  of  the  same,  magnified  ;  c,  syr- 
phus;  d,  larva  of  the  same  <levourinj5  the  aphides  of  the  elder; 
e,  the  head  niaguificd,  to  show  the  mouth. 

*  Intl.,  i.  261. 


VORACITY  OF   INSECTS.  271 

are  hollow,  by  means  of  which  they  suck  the  juices 
of  their  victims.  They  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. 


(  272  ) 


SECTION  III.— PUPiE. 


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  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 ;  made  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. "f 
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.         f   Intr.,  iii.  209. 


SUSPENSION  OF   PUP^.  273 

salis,  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  tortoiseshell  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  hniterRy  {Vanessa  Ata- 
lantd)  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  draw^n  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. 


a.  Caterpillar  of  Vanessa  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    FVFM.  275 

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  chrysahs 
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.  Repeat- 
ing this  process  several  times,  it  at  length  arrives  at 
the  silk  button. 


a,  suspended  caterpillar  of  Vanessa  Antiopa  splitting  its  sliin  for 
the  evolution  of  the  chrysalis,  h,  the  head  of  the  chrysalis  emerg- 
ing,   c,  the  same  process  farther  advanced,     d,  the  perfect  pupa. 

The  tail  of  a  chrysalis,  to  an    ordinary  observer, 
would  appear  smooth,  and  quite  unfitted  for  being 


I 


SUSPENSION   OF  PUP^,  277 


fixed  to  the  silk  in  such  a  manner  as  to  sustain  its 
weight ;  but  careful  examination  discovers  that  it  has 
i  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. 
I  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  To),  the  same  upon  which 
Re^aumur  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. 


278 


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.  Reaumur  says  that  this  gyration 
usually  throws  off  the  slough,  in  consequenee  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 


bv-     Besides,  the 


threads  of  the  silk  are  not  broken  by  the  gyration,  as 
Reaumur,  follow^ed  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  sa- 
tisfied us,  therefore,  that  the  twirling  of  the  chrysalis 
is  both  for  the  purpose  of  disengaging  the  old  skin 
and  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 
observed  that  the  insects  which  change  into  chrysalides. 


a,  h,  front  and  side  view  of  chrysalides  of  Vanessa  UrticcB  sus- 
pended by  their  anal  hooks,  c,  old  skin  fallen  off.  d,  anal 
hooks  macnilied. 

*  J.  R. 


SUSPENSION  OF  PUP^.  279 

after  being  removed  from  their  suspensories,  also  roll 
about  and  manifest  great  uneasiness.* 

But  this  is  only  one  mode  by  which  chrysalides 
are  suspended  ;  for  nature,  rich  in  variety,  has  taught 
others  to  employ  a  different  mechanism,  and  consi- 
derably 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  (TheclcF,  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  Thecia  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,  indeed,  of  this  whole  family  (Lyccenceidce, 
Leach),  which  includes  our  splendid  blue  and  copper 
butterflies,  seem  to  follow  the  same  process,  repeat- 
ing 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  {Pieiis 
CratcBgi,  Stephens).  A  caterpillar  of  this  kind, 
■•'  Bonnet,  CEuvies,  vol.  ii.  p.  109. 

r2 


280 


INSECT  TRANSFORMATIONS. 


however,  though  it  forms  a  silken  suspensory  girth 
similar  to  the  Lyccpnmdre^  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 


a,  ( 'aterpiliar  of  the  black-voined  white  butterfly  spinning  its 
suspensory  band,  b,  chrysalis  horizontally  Ixjund  to  a  branch, 
f,  the  butterfly  {Pieris  Cr'atceai),  smaller  than  in  nature. 


SUSPENSION  OF  PUP^.  281 

the  manner  of  the  leaf-rollers,  another  most  unusual 
and  remarkable  circumstance.* 

Another  caterpillar  of  the  same  family,  that  of 
the  awaliow-tailed  butterfly  (Papilio  Machaon, 
Linn.),  one  of  our  finest  but  local  native  insects, 
having  a  body  less  pliable  than  the  preceding,  has 
recourse  to  a  still  different  method  of  forming  a 
cincture.  The  proceedings  of  this  beautiful  cater- 
pillar, distinguished  by  two  retractile  horns,  like 
those  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 


ffl,  Caterpillar  of  the  swallow-tailed  butterfly,  weaving  its  sus- 
pensory cincture,  b,  the  caterpillar  suspended,  for  its  change,  o, 
the  chrysalis  suspended  in  a  similar  manner. 

*  J.  li. 

r3 


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- 
times happens  that  they  slip,  in  whole  or  in  part,  from 
the  claws  of  the  caterpillar  ;  and  Reaumur  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 
pupae,  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  pupse.  The  mag- 
got of  the  common  blow-fly  {Musca  vomitoria),  for 
example,  when  about  to  undergo  its  transformation, 
quits  the  carcass  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  Insectcs,  vols.  i.  ix. 


CONTRACTION   OF  PUPiE.  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 
Swammerdam  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 
ghiten,  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  inimoveably  glued  dovm  there.  When  thus 
securely  fixed,  it  contracts  and  shortens  its  body 
similarly  to  the  maggot  of  the  blow-fly  ;  but,  instead  of 
becoming,  like  that,  uniformly  oblong,  the  head  swells 
out  and  the  tail  becomes  slender,  till  it  terminates  in 
a  point,  just  reversing  the  previous  form  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,  and  were  not  a 
little  surprised  to  see  large  wasp-looking  flies  issue 
from  them ;  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 


^axiiirs> 


n.  Pupa  of  blow  fly,     b,  Uie  s;iinc  miignifiotl.     c,  head  of  pupa- 
rium  opened  to  show"  the  cast  mandibles,    d,  piija  of  Si/rphus. 


PUP^  OF  LADY-BIRD.  285 

flies  make  reprisals  upon  them  for  their  destruction  of 
the  helpless  aphides.  Swammerdam  observed  eight 
of  these  parasites  issue  from  one  pupa  of  a  Syrphus.*" 

The  lady-birds  (Coccme^/zc?<^)  glue  their  pupse  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  jUu- 
micornis^  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  cristaliina, — 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  details^  that  are 
not  in  the  otherwise  very  accurate  figures  of  Rt^au- 
mur. 

The  larva  is  rather  less  than  a  quarter  of  an  inch 
long,  and  somewhat  resembles  in  form  those  of  the 
game  family,  particularly  in  the  parts  about  the  head, 

*  Part  ii.  p.  99.  f  J.  R. 

+  Goring  and  Pritchard's  Nat.  Hist.,  No.  1 ;  and  Reaumur^ 
vol.  v.,  mem.  1. 


286  INSECT  TRANSFORMATIONS. 

the  mandibles  being  liorny,  jointed,  and  capable  of 
uniting  into  one  pointed  borer.  The  tail  is  furnished 
with  plumed  bristles,  which  appear  to  serve  the  pur- 
pose of  fins.  The  nearer  this  chrystalline  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- 
tennae 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  "  not  efiected,  as  in  other  insects, 
by  casting  the  outer  skin,  but  by  an  actual  conver- 
sion of  one  form  of  matter  into  another,  "f  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.  )n 
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, 


TVTM  OF  GNATS. 


28: 


a,  a,  larva  of  Carethra  plumicornis  magnified,  b,  the  mandibles 
and  palpi,  c,  the  respiratory  tins,  d,  the  pupa  magnified,  e, 
pupa,  natural  size.  /,  larva,  natural  size,  g,  the  female  liy.  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. 


(    288    ) 


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  larvee  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  Metamorphons, 
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  I 
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  1 
which  have  obscured  and  perplexed  this  branch  ofl' 
our  subject. 

We  shall  begin  with  the  illustrious  Harvey, — the 
discoverer  of  the  circulation  of  the  blood, — who,  in 


OPINIONS   RESPECTING   INSE(;TS.  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  })aring  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 
increased  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  in- 
sects is  performed  after  the  first  manner ;  the  G§g,  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  au- 
relia  (pupaj^  a  butterfly,  or  a  common  fly.  "Bees," 
he    subjoins,    "  wasps,   hornets,    or   butterflies,    and 


290  INSECT  TKANSFOilMATIONS. 

whatever  other  animals  are  generated  by  metamor- 
phosis from  a  creeping  insect,  are  said  to  be  the  off- 
spring of  chance,  and  therefore  never  to  keep  up  their 
species.  But  the  hon  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  "  that 
wherever  the  legs  are  situated  in  the  caterpillar, 
there  is  placed  the  back  of  the  insect  which  is  to 
arise  by  transmutation :  and,  on  the  contrary,  where 
the  back  of  the  caterpillar  w^as,  there  are  the  legs  in 
the  insect  to  be  produced  from  it.  This  metamor- 
phosis," he  adds,  "  is  performed  in  a  short  space  of 
time,  so  that  it  may  be  distinctly  seen ;  because, 
immediately  after  shedding  its  skin,  this  change  ap- 
pears 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,  t  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  Generat.  Anim.,  Exercit.  xlv. 
'  t  De  Insectis,  Exp.  77. 
X  See  our  quotation  from  Goring  and  Pritchard,  p.  2^^G. 


STRUCTURE  OF   FUP^.  291 

structure   of  pupae,  rather  than  stop  to    refute    cir- 
cumstantially the  preceding  theory  of  Harvey  and 
Goedart. 
i       In  the  pupa  state,  then,  we  may  remark,  that  the 
I  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  con- 
siderably 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. 
j       As  we  have  shown  all  the  parts  of  the  perfect  in- 
sect 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 
i  — that  it  would  be   next    to   impossible   to    develop 
!  them  artificially.     In  some  pupae  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. 
I        The  first  we  shall  advert  to  is  that  of  the  chame- 
*  Goedart,  de  Insectis,  77. 

S2 


292 


INSECT  TRANSFORMATIONS. 


leon-fly  ( Stratiomys  chameleon )y  whose  sirigular 
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  ex- 
terior skin,  becoming  greatly  contracted ;  and,  ga- 
thering into  three  or  four  curvatures,  the  extremity 
is  thereby  left  empty.  Into  this  space  the  air  pene- 
trates 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  tlie  Ud  of  the  pupariiim  raised. 
B,  the  same  magnified,  and  the  puparium  laid  open  to  slio«-  tlie 
embrvo  lly.  C,  the  embrvo  fly  magnitied  —a  a,  anteniire  ;  t>  h, 
the  eyes;  c,  sncker ;  d  d,  "first  pair  of  legs;  e  e,  second  pair  : 
//.  the  wings  folded  up ;  </  A  i,  rings  of  the  body  ;  k  k.  broathing- 
tubes. 

*  Pa?c  156,  7. 


FORM  OF  PUP^.  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  envelope, 
be  cut  open,  the  pupa  will  be  brought  into  view,  ex- 
hibiting 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  (Gastrojmcha 
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  on  the  part  of  Provi- 
dence. It  was  by  opening  one  of  these  pupse  that 
Reaumur  first  discovered  the  various  sheaths  appro- 
priated to  the  feet,  the  antennae,  and  the  wings ;  the 
sheath  of  the  sucker  (kaustellum)  being  wanting,  as  it 
*  Bibl.  Nat.,  vol.  ii,  p.  54. 


\ 


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     I 
alkided  might  term  its  leaf  stalk. 


a,  Pupa  of  lappit-moth  ;  b,  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  loj,  whose 
catei  pillars  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, and  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 


STKUCTURE  OF  FUP^.. 


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-grey. 
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  pcacook-butterlly.  /»,  the 
wings  and  antennae  traced  out  from  tlie  same,  c,  tlie  perfecl  in- 
sect (p^anessa  I<})  fully  developed. 


296  INSECT  TRANSFORMATIONS. 

membrane  which  covers  the  more  prominently  ex- 
posed 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 
considered  the  matter  as  proved,  and  admired  the  sup- 
posed metamorphosis,  without  giving  themselves  the 
trouble  of  investigating  whether  it  was  real  or  pos- 
sible.t  Accurate  observation,  founded  on  the  prin- 
ciples 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."  I  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 

*  Swammordatn,  vol.  ii.  p.  17. 
f  Ueanmur,  vol.  i.  ]).  350.     |  Harvey,  De  Gen.  An.,  Kxer.  44. 


STRUCTURE  OF  PUP^..  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  appli- 
cation requisite  to  give  an  imposing  air  to  such 
absurdities." 

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  affected  by  the 
evaporation  of  the  superabundant  fluids.  Thus  he 
tells  us  that  the  nit,  or  egg  of  the  louse  (Pediculus 
humanusj,  is  nothing  more  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 
misinterpreted  them.  "  If  you  open  a  pupa,"  say 
*  Sv/ainmerdam,  passim. 

s  3 


298  INSECT  TRANSFORMATIONS. 

they,  "  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  en- 
closed animal  by  the  absorption  and  assimilation  of 
the  residuum."*  The  evaporation,  however,  is  so 
very  inconsiderable,  that  it  is  evidently  only  of  se- 
condary 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  ex- 
tension or  to  the  repair  of  our  bones  and  muscles. 
To  put  this  to  the  test  of  experiment,  R(5auraur,  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  more  than  J  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  FUP^.  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- 
serves, 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  tiie  eye.t  That  they  do 
find  their  way  thither,  the  experiments  above  re- 
corded unanswerably  demonstrate. 

The  pupae  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- 


■•'  Reaumur,   vol.   i.   p.   373,  "  Une  goutte  beaucoup  plus 
grosse  ;''  and  Kirby  and  Spence,  Intro,  iii.  262. 
t  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 
fluid  stored  up  by  the  caterpillar,  and  forming  or 
perfecting  therefrom  the  organs  and  members  of  the 
mature  insect.* 

Some  pupse  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 
perfect  insects.  We  have  adverted,  in  a  former  page, 
to  the  eighteen  spiracles  which  communicate  with  the 
double  windpipe  of  caterpillars,  and  the  same  appara- 
tus is  always  found  in  chrysalides,  situated  on  the 
sides  of  the  abdominal  rings.  This  we  think  might 
have  convinced  such  distinguished  observers  as  Lyon- 
net  and  Muschenbruk,  that  the  most  quiescent  pupse 
could  not  exist  without  breathing. 


a,  Clifj'salis  of  Gi-nepteryx  Rhamni.    h,  pupa  of  Lariafns  clina. 
c,  pupa  of  Sphin.v  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  injui  ed,  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.  By  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 
experiments  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  pupae  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, 


302 


INSiiUT  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  moist- 
ening it  before  immersion.* 

Upon  examining  the  structure  of  the  spiracles, 
M.  Reaumur  further  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  for- 
cibly 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.f  It  may  be  recollected  that  the 
larvse  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 


Spiracles  of  pupcc.     a,  the  valve  open  ;  b,  the  same  shut. 

In  the  aquatic   pupa,  of  the  ringed  China-mark 
moth  (Hydroeampa  stratiotata,  Stephens)  De  Geer 

*  Bonnet,  CEuvres,  vol.  iii.  p.  39,  &c.     f  Mem.  i,  407,  &c. 
I  See  page  265. 


STRUCTURE  OF  VVFM.  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  re- 
spiratory 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  larvse  of  the  gnat  family 
{CulicidcPy  Latr.)  ;t  but  this  is  rivalled  by  the  or- 
gans destined  for  the  same  purpose  in  their  pupse, 
which  organs  are  situated  in  the  head  instead  of  the 
tail.  The  pupa,  in  the  same  way,  changes  its  po- 
sition in  the  water,  swimming  with  its  head  upwards 
instead  of  downwards,  as  before.  To  enable  it  to 
maintain  this  position,  the  pupa  is  further  provided 
with  a  fin-tail,  like  a  fish,  by  which  it  can  move  itself 
at  pleasure  in  the  water.  It  no  longer,  indeed,  re- 
quires 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  re- 
markable apparatus  for  respiration,  was  observed  by 

*  De  Gecr,  Mem.  i.  531.  f  See  page  156. 


304 


INSECT  TRANSFORMATIONS. 


Reaumur  in  the  pupa  of  a  small  crane-fly  {Tipula, 

).     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. 


o,    Tipvla, ?    b,   telescope-tailed   pupa    of   the    same. 

c,  front  view  of  the  pupa    of  the  common  gnat  {Culex  pipiens). 

d,  side  view  of  the  same. 

In  another  genus  of  this  family  the  external  organs 
of  respiration  are  very  elegant  in  form,  resembling 
more  the  fibrillse  of  minute  aquatic  mosses  (Con- 
fervoidecF)  than  the  appendages  of  an  animal.  The 
larvje  of  this  insect  is  well  known  to  anglers,  under 
the  name  of  the  hlood-worm  ;  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 


STRUCTURE  OF  PUP^. 


305 


the  tail,  which  appear  to  be  breathing-tubes,  of  the 
nature  of  gills  ;  for  the  larva  lies  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  opaque  in  the  pupa  state. 


n,  Chmmomus  plumnsua.  h,  larva  of  the  s;»me,  called  the 
hliiod  worm,  c,  d,  \n\y.3a  of  the  same,  maguified  to  show  theiv 
plumed  spiracles. 


306  INSECT  TRANSFORMATIONS. 

The  appendages  which  are  thrown  otF  by  the  larva 
are  replaced  by  a  brush-like  bunch  of  bristles,  the 
points  of  which,  it  is  probable,  have  the  power  of 
extracting  air  from  the  w^ater ;  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  remark- 
able that  a  double  envelope  for  the  feet  projects  from 
each  side  of  the  breast,  a  circumstance  which  seems 
peculiar  to  this  insect.  In  a  few  days  it  is  trans- 
formed into  a  pretty  gnat,  with  feathered  antennae 
{Chironomus  plumosus,  Meigen). 

Such  are  a  few  examples  of  the  beautiful  contri- 
vances for  carrying  on  the  important  process  of  re- 
spiration in  that  stage  of  life  during  w^hich  few  insects 
take  any  food.  Considering  the  great  difficulties  pre- 
sented 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  re- 
spiration on  the  fluids  of  pupae. 


(   307   ) 


Chapter  XIII. 

Transformation  of  Pupae  into  Perfect  Insects. 

The  period  which  pupae  require  to  come  to  maturity 
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 
immediately  have  to  record  several  curious  facts  quite 
at  variance  with  such  a  conclusion.  "  It  is  plain," 
say  Kirby  and  Spence,  "  that  this  necessary  transpi- 
ration, 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  temperature  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  the  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  IXSECT  TRANSFORM ATIOIN'S. 

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  evapo- 
ration being  the  exclusive  effect,  is,  upon  the  whole, 
inadmissible.  Reaumur,  though  he  does  not  abso- 
lutely state  his  belief  in  such  an  inference,  shows  by 
his  reasoning  that  he  was  strongly  disposed  to  adopt 
notions  closely  Iwrdering  upon  it.  The  theoretical 
doctrnie,  it  may  be  perceived,  takes  for  granted  that 
evaporation  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  decomposed.  But  these  are  only 
some  of  its  inanimate  results,  which  would  occur 
upon  material  objects  independently  of  life;  whereas 
in  living  bodies,  what  maybe  called  chemical  changes 
are  frequently  very  different  from  what  can  be  effected 
out  of  the  living  body,  and  consequently  we  cannot 
trace  all  the  effects  produced  by  heat  in  the  two  great 
internal  processes  of  secretion  and  consolidation. 
In  detailing,  therefore,  the  interesting  experiments 
of  Reaumur  on  pupae,  which  he  subjected  to  different 
degrees  of  heat  and  cold,  we  shall  not  adopt  his  in- 
fer^;nces  respecting  evaporation.  The  accuracy  of 
the  experiments  themselves  is  unquestionable. 

Reasoning  from  some  of  the  facts  above  stated, 
Reaumur  thought  it  might  be  possible  to  hasten  or 
retard  the  exclusion  of  insects  from  their  pupje,  in 
the  same  way  as  some  flowers  are  forced  to  blow 
early,  and  others  kept  back  from  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 
*  Iiitr.  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,  Rt^aunmr  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  Machaoji)  is  one  of 
those  which  are  double  brooded,  the  first  going  into 
chrysalis  in  July,  and  the  butterfly  ai)pearing  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 
efltects  produced  by  birds  sitting  upon  their  eggs  in 
order  to  hatch  them.     He  concluded,  that  if  chrv- 


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  chrysahdes  which  he  first  tried  were  those  of  the 
small  tortoiseshell  butterfly  ( Vanessa  Urlicce),  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  22nd 
of  June.  The  aperture  of  the  glass  egg  was  closed, 
but  in  such  a  manner  as  to  leave  a  communication 
with  the  external  air.  The  effect  of  the  heat  manifested 
itself  the  first  day,  in  the  moisture  exhaled  from  the 
chrysalides,  all  the  interior  of  the  glass  being  covered 
with  minute  drops  of  water,  which  he  allowed  to  eva- 
porate 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  ihe  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-butterfiy  {Vanessa 
lo).     With  the  pupse  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  pupse  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  pupse 
he  could  obtain.  We  have  in  several  instances  suc- 
ceeded in  obtaining  butterflies  in  winter,  by  keeping 
chrysalides  under  glasses  on  a  mantelpiece  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 
eff^ects  which  he  had  anticipated,  Reaumur  next  tried  an 
opposites  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,  1 734.  During  the 
hot  months  of  this  year  he  went  from  time  to  time  to 
see  whether  these  pupse  indicated  an  approaching 
change,  but  they  remained  in  their  original  state 
during  July  and  August,  and  continued  so  till  the  suc- 
*  Reaumur,  Mem.  vol.  ii.  p.  17. 


312  INSECT  TRANSFORMATIONS. 

ceeding  August,  1735,  at  the  time  he  was  writing  this 
account,  when  he  found  them  still  living  and  heahhy, 
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 
pupae  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 
Brassiccs),  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  Urtica;),  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  2nd  and  3rd  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  OF  INSECTS.  313 

the  envelope,  taking  care  to  leave  the  respiratory 
spiracles  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 
Reaumur's  experiments  with  the  varnished  chrysalides 
was,  that  they  were  developed  several  weeks  later 
than  wlien  placed  in  their  natural  circumstances, — 
which  proves,  we  think,  that  the  envelope  has  consi- 
derable influence  on  the  transformatory  process  going 
on  in  the  interior,  even  were  we  to  leave  the  trans- 
piration of  moisture  out  of  the  question.* 

We  may  remark,  that  the  resuUs  of  these  experi- 
^ments  afford  interesting  illustrations  of  the  torpidity 
of  both  the  larger  animals  and  of  plants.  In  ihe 
United  States  of  America,  for  example,  many  species 
of  animals  which  become  torpid  in  Pennsylvania,  and 
other  more  northern  parts  of  the  country,  remain 
lively  in  the  Carolinas,  and  other  southern  parts  of 
the  continent.!  Mr.  Gough  found  that  the  dormouse 
may  be  prevented  from  becoming  torpid  by  supplying 
it  plentifully  with  food  ;  and  Dr.  Reeve,  of  Norwich, 
observed  the  same  circumstance  in  a  hedge-hog, 
which  being  kept  warm  and  well  fed,  showed  no  dis- 
position to  become  torpid  even  during  severe  weather. | 
Pallas  had  a  tame  marmot,  also,  which,  having  be- 
come very  fat  during  the  summer,  showed  no  dispo- 
sition to  torpidity,  though  exposed  to  a  temperature 
which  threw  the  whose  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  frost.     Mr.    Gough 


*  Reaumur,  Mem.  vol.  ii.  p.  56. 

•V  Barton,  in  Amer.  Phil.  Trans,  vol.  iv. 

I  Reeve  on  Torpidity,  p.  73. 

T 


314  INSECT  TRANSFORMATIONS. 

made  some  ingenious  experiments  in  proof  of  this 
upon  several  plants,  such  as  the  small  duck's  meat 
{Lemna  minor),  and  the  viviparous  fescue  grass  (Fes- 
tuca  vivipara),  which  led  to  the  conclusion  that  they 
could  accommodate  themselves  without  perishing  to 
the  vicissitudes  of  variable  situations.* 

We  observed  a  no  less  marked  instance  than  those  i 
recorded  by  Mr.  Gough,  in  a  plant  of  the  geranium,  ,; 
named  Prince    Leopold  {Pelargonium   macranthon,  ' 
Sweet),    the   whole   of  whose  leaves  were  so   hard 
frozen  as  to  break  rather  than  bend.     We  immersed 
the  whole  of  the  plant  in  cold  water,  a  few  degrees   j 
above  freezing,  till  it  was  thawed,   and  it  recovered    I 
so  completely  that  not  a  single  frosted  spot  appeared 
on  any  of  the  leaves. t 

Several  extraordinary  facts  relating  to  insects  prove 
that  temperature  alone  will  not  account  for  the  vari- 
ations for  the  periods  of  their  disclosure.     It  is  stated 
by  Marsham,  that  Mr.  Jones  of  Chelsea,  in  one  of  , 
his  excursions,  caught  a  female  of  the  spotted  muslin-  ' 
moth  {Diaphora  mendica,  Stephens),  which  laid  a  j 
number  of  eggs,  and  he  fed  thirty-six  of  the  cater- 
pillars hatched  from  these,  till  they  spun  their  cocoons 
and  became  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.  4: 

The  same  extraordinary  fact  has  been  observed  in 
the  pupae  of  the  small  egger-moth  {Eriogaster  la- 
nestris),  the  greater  number  of  those  which  spin  up 
in  summer  appearing  in   the  succeeding  February  ; 


Manchester  Trans.  f  J.  R- 

I  Linn.  Trans,  vol.  x.  p.  402. 


EXPERIMENTS  OF   IXSECTS.  315 

but  others  of  them  requiring  two,  three,  and  even 
four  years  *  Meinecken  kept  several  pupae  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.t 

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.]:  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  unneces- 
sary 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  usu- 
ally on  many  successive  days,  as  may  be  seen  by  the 
experiments  of  Reaumur  recorded  at  the  beginning  of 


*  Scriba,  Journ.  i.,  vol.  iii.  p.  222  ;  and  Haworthj  Lepiclopt. 
Brit.,  vol.  i.  p.  125. 

f   Naturf.,  vol.  vili.  p.  143.  +  J.  R, 

§  Kirby  and  Spence,  vol.  iii   ]\  '^Ql . 
T    2 


316  INSECT  TRANSFORMATIONS. 

this  chapter.  In  the  instance  of  the  clear  underwing 
{Mgeria  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  grandijlorus')^ 
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  Cardamincs^^  which  is  usually  seen 
about  the  end  of  April,  varying  but  few  days  in  the 
course  of  many  years.  The  various  species,  also,  of 
May-flies  {Ephemerce)  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  snovv- 
flake.t 

The  pupae  of  these  May -flies,  when  about  to  un- 

*  J.  R.  t  J.  K. 


MODES  OF   EMERGINGFROM  PUP^.  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  v/ater  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  rugosity  of  the  envelope,  which  it 
is  throwmg  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,  "  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   ripple   the 

T  3 


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  mucli 
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-iegs,t  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  (Cidex  jn'jnens)  escaping  from  the  pupa. 
*  Mem.,  vol  iv.  p.  613. 

f  Kirby  and  Spence,  by  mistake,  say  it  "  draws"  these  ^' out 
of  their  case,''  vol.  iii.  p.  288. 


MODES  OF  EMERGING  FROM  PUPiE.         319 

spent  the  first  stages  of  its  existence.  "  It  leaves," 
says  Swammerdam,  "  its  cast  skin  on  the  water,  where 
it  insensibly  decays."*  Reaumur  doubts  whether 
Swammerdam  ever  actually  saw  this  interesting  trans- 
formation.    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  beautiful 
contrivance,  which,"  says  Kirby,*' I  shall  explain,  the 
more  particularly  because  it  has  escaped  Reaumur 
and,  as  far  as  I  know,  all  other  entomological 
observers.  The  middle  of  the  back  of  the  thorax 
has  the  property  of  repelling  water,  apparently  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,t  the  thorax,  which  belongs  to  the 
heaviest  half,  being  the  lowest;  and  if  the  pupa  be 

*  Part  i.  156. 

f  But  if  so,   we  may   ask   \vha(   lias  become  of  the  power  of 
tlje  thorax  to  repi'l  water?   J.  R. 


320  INSECTT  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 
pupariumj  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  {PhryganidcB,  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  VaUisnieri.  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  Geer)  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  the  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 

-  In(r.,  iii.  p.  290.     -j-  "Do  Goer,  Mem.,  vol.  ii.  p.  519-45 


MODES  OF  EMERGING  FROM  PUP^. 


321 


breathing,  by  admitting  a  current  of  fresh  water, 
effected,  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 
j  and  in, 

I  Our  motive,  however,  for  introducing  a  notice  of 
'i  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 
transformation  into  a  %,  as  was  observed  by  Vallis- 
nieri.  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. 


a,  Pupa  of  a  case-fly  (Phryganea).  c,  d,  grate-wofks  of  tlie 
same  at  the  openings  of  the  cases,  greatly  magnified,  b,  the 
perfect  insect. 

In  the  comm.on  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  dif- 
ferent, b\it  no  less  admirable  contrivance.  The  head 
of  the  perfect  fly,  it  may  be  remarked,  is  hard  and 
unyieldmg  ;  but  in  the  pupa  it  is  soft,  and  capable 


322  INSECT  TRANSFORMATIONS. 

of  great  distention.  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  transformation,  when  the  movements  be- 
come obvious.  The  same  mechanism  occurs  in  the 
pupae  of  some  of  the  fibrous  gall-flies  (Tephrites), 
for  the  purpose  of  dissevering  the  woody  fibres 
which  imprison  the  insects.  In  the  instance  of  the 
thistle  gall-fly  (Tephritis  Carclui),  Reaumur  found 
that  those  kept  in  his  study  often  became  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  accident  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. 'I' 

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  com- 
mon-sewer fly  (Eristalis  tenax,  Fabricius),  w^hich 
was  observed  by  Reaumur  to  push  off  the  lid  of  its 
pupa  case  by  means  of  its  tail. 

The  caterpillar  of  the  clear-wing  hawk-moth 
{Mgeria  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 

*  """ r,  iv.,  Mem.  S.  '  f  J.  I{. 


MODES  OF  EMERGING  FROM  PUP.^..         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,  but  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  consi- 
derable force  in  this  process,  by  means  of  the  beauti- 
fully-serrated structure  of  its  rings,  resembling  in  this 
respect  the  caterpillars  of  cossus  and  other  wood- 
borers. 


Pupae  of  Cossus,  a,  and  ^geria,  b,  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 
I  has  given  a  very  interesting  account  of  similar  pro- 
i  ceedings  in  the  case  of  the  locust-moth  {Cossus  Ro- 
binifp.  Peck).      "  In   the  silk-moth,"  he  says,  "  and 
all  others  which   I  have  had   an  opportunity  to   ob- 
serve, 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,t  that  the  moth  is  able  to  extri- 
cate itself,  leaving  the  chrysalis  behind  it ;  but  this  is 
not  the  manner  in  the  locust-moth.    After  remaining 
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 

*  JR. 

f  See  some  observations  on  this  doctrine,  "Insect  Architec- 
ture," pages  31(5,  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 
observed  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, 
resembling  a  grain  of  oats.  The  chamber  w^hich  it 
forms  is  not  only  extensive  in  proportion  to  the  size 
of  the  insect,  but  is  so  very  compact,  that  it  does  not 
appear  in  what  manner  it  is  to  effect  its  escape. 
Within  the  capacious  chamber  of  the  leaf  it  hangs 
itself  up  by  two  lines,  after  the  manner  of  a  sailor's 
hammock.  But,  previous  to  this,  it  gnaws  a  cir- 
cular piece  half  through  the  leaf,  taking  care  not  to 
injure  the  exterior  membrane.  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    granelld),    which    we 
have  before  mentioned  as  destructive  to  grain.     The 

*  Peck,  quoted  by  Kirby  and  Spence. 
f  Bonnet,  CEuvres,  vol.  ii.  p.  207. 


MODES  OF  emergi:ng  Fr.OM  PUP^.        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  silvestris).  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  entire,  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  further  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  rapacious  insects  from  without ;  and  he  gives  a 
very  minute  detail  of  his  discovery  of  this  fortifica- 

i: 


326  INSECT  TRANSFOPaiATIONS. 

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  gnawing  through  the 
wall,  the  insect  has  eaten  about  an  eighth  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  proceed- 
ings of  the  insect  may  be  easily  examined. t 

A  similar  prospective  contrivance  occurs  in  the 
instance  of  a  caterpillar  which  feeds  on  the  cow 
parsnip  (Heracleum  spondylium').  and  makes  a  cir- 
cular 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 
pupse  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  {Tifulce  oleracea;?)  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  Hies  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.         f  J.  R. 


MODES  OF  EMERGING  FROM  PUP^.    327 

and  forwards,  and  shifting  their  hold  till  she  was 
entirely  extricated,  when  they  left  her  to  recover  her 
strength  by  herself.  "  Probably,"  say  our  authors, 
"  the  extreme  length  of  the  two  pair  of  l>ind-legs  of 
these  animals  may  render  such  assistance  necessary 
for  their  extrication."*  We,  however,  imagine 
that  Captain  Percy's  instance  was  accidental  and 
anomalous ;  for  the  insect  having  already  extricated 
her  head,  shoulders,  and  fore-legs,  all  the  difficulties 
were  surmounted.  From  the  insect  being  so  very 
common,  also,  the  circumstance  of  such  assistance, 
if  it  did  happen,  must  be  a  matter  of  frequent  ob- 
servation;  but  we  have  witnessed  a  considerable 
number  of  several  species  of  this  family  undergo  the 
change  without  any  assistance  whatever. f 

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  pupae,"  says  he,  "  are  enclosed  in 
a  tissue  spun  by  themselves  before  their  change ; 
but  they  cannot,  like  other  insects,  liberate  themselves 
fi-om  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.  2^«  f  J.  R. 

u   2 


328  INSECT  TRANSFORMATIONS. 

antennae ;  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  slill  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  PUP^..  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  w^alk,  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  antennas  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.  The 
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  parti- 
cular apartments."* 

A  very  interesting  experiment  upon  this  subject 
was  tried  by  Dr.  J.  R.  Johnson,  of  Bristol.  "  Among 
*  Huber  on  Ants,  p.  88. 


330  INSECT  TRANSFORMATIONS. 

those  ants  I  kept  in  confinement,"  says  he,  "  I  ob- 
served that  considerable  bustle  prevailed  when  any  of 
the  pupse  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  jlava)^  with 
three  or  four  pupas :  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  pupse  were  or  were 
not  capable  of  effecting  their  own  liberation  ;  but  ac- 
cording to  the  statement  of  De  Geer,  the  pupa  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. 
"  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  pupse  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."t  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.  130. 


MODES  OF  EMERGING  FROM  PUP^.  331 

"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  thoroughly  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  pupae  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  uncovered, 
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  ab- 
domen. 

Huber  was  exceedingly  anxious  to  discover  whether 
the  royal  grubs  spun  their  cocoons  imperfect  in  con- 
sequence 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  co-  I 
coons,  and  introduced  them  into  glass  cells  blown 
of  varying  dimensions.  "  They  soon  prepared  to 
work,"  he  says,  *' 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  larvfp,  being 
«^)i)liged  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 
Fpin  complete  cocoons  in  the  same  manner  as  the 
larvoe  of  workers.  In  fine,  I  put  plebeian  larvae  into 
very  wide  cells,  and  they  left  the  cocoon  open,  as  is 
done  by  the  royal  larvie.  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 
inposes  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  sin- 
gular."* 

*  Hubcr  on  Bees,  p.  133. 


333 


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  till  and  distend  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  much 

u  3 


334  INSECT  TRANSFORMATIONS. 

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  transformation  of 
the  ant-lion  (JS'Iyrmcleon  formicarium),  whose  sin- 
gular 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  co- 
coon 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  out- 
side, 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  outside  it 
only  requires  to  expand  its  wings  and  body  to  complete 
its  transformation.  But  this  is  the  process  most  cal- 
culated 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  "  Insect  Architecture,""  page  209,  &c. 


EXPANSION  OF  PERFECT  INSECTS. 


135 


of  its  first  form,  so  is  it  likewise  divested  of  its  bar- 
barity and  ravenous  malignity ;  but  the  formidable 
structure  of  its  mandibles,  as  Rt^aumur  justly  remarks, 
evidently  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  (Libellulijia),  except  in  being  more 
slow  in  flight,  affords  a  strong  analogical  indication  of 
its  carnivorous  propensities. 


a,  Myrmefeon  formicarium,  the  fly  of  the  ant-lion,  b,  the  heaii 
magnified  to  show  the  calliper-formed  mandibles,  c,  the  pupa. 
d,  the  pupa  escaping  from  its  cocoon. 

A  Still  more  striking  difference  of  size  may  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. t  The  cocoon  of  this 
*  Mem.,  vol.  vi.  p.  375,  f  See  page  45. 


33G  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 
mcreasmg  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  immoveable.  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, 
while  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  exertiim,  or 
rather  to  allow  the  newly  excluded  parts  to  dry  and 
become  more  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  immoveable. 
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  the 


EXPANSION  OF  PERFECT  INSECTS. 


A,  the  dragon-fly,  beginning  to  escape  from  tlie  pupa  ;  a,  the  fly  ; 
b,  tne  pupa  case.  B,  the  process  further  advanced  ;  c,  the  fly  ;  d, 
the  pupa  case.  C,  the  fly  nearly  free,  and  rormiu;,'.inarc]i ;  J,  the 
fly  ;  /,  the  pupa  case.  1),  the  fly  bending  bavk  its  body,  so  as  not 
to  obstruct  the  expansion  of  the  winys. 


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 
Swammerdam,  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,  however,  that  we  can  surprise  insects  at  the 
precise  moment  of  their  transformation,  as  it  is  for 
the  most  part  very  speedily  accomplished,  for  the 
whole  of  the  preceding  evolutions  are  usually  com- 
pleted in  ten  or  fifteen  minutes.  "  It  happened  by 
mere  chance,"  says  Swammerdam,  "  that  I  observed 
them  for  the  first  time :  one  of  these  vermicles  ad- 
hered to  a  stone  wall  in  the  river  Loire,  and  it  was 
so  softened  by  the  water  dashing  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  {Mshna  ?  )  which  had  crept  to  land  out  of 
a  small  lake,  and  cast  its  skin  sitting  in  the  grass." 


a,  newly-hatched  blow-fly  magnified,  showing  the  pulpy, 
crumpled  state  of  the  whigs.  b,  the  wings  dry  aud  fully  ex- 
pa  ndi-d. 

*  Ribl,  Nat.,  vol.  i.  p.  08. 


EXPANSION  OF  PERFECT  INSECTS.  339 

Some  species  of  flies  have  their  wings  shortened 
very  considerably  in  the  pupa  state  by  zigzag  or 
transverse  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  translucent,  as  they  are  actually  seen  to 
do.  This  will  be  better  understood  from  the  above 
figures  than  by  description.  ^ 

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 
branching  of  the  tubes  (nervures)  through  them  is 
more  obvious  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  better  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 
silkworm    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  con- 
vulsed ;    so   that   the   several   circular   folds   of  the 
segments  emerge,  and  by  the  transverse  contraction 
of  the  sides,  the  external  skin  is  separated  from  the 
inner  ;  hence,  upon  making  an  effort,  and  thrusting 
the    body,   which    now   appears    particularly    thick, 
towards  the  head,  the  skin  is  driven  backward  and 


340  INSECT  TRANSFORMATIONS. 

downward;  and  the  portions  of  the  windpipe  being 
separated  from  their  external  proper  orifices,  are 
thrown  away  with  the  skin  which  is  then  cast  off. 
By  this  motion,  a  cleft  or  opening  is  made  in  the 
back  near  the  head,  and  through  the  aperture  the 
body  makes  its  way,  the  skin  being  by  degrees  drawn 
back  towards  the  tail.  This  process  is  assisted  greatly 
by  a  yellow  kind  of  ichor  which  exudes  from  the  cavities 
of  the' skull;  and  the  pupa  appears  then  free  and 
disengaged. 

"  While  the  insect  is  making  its  passage  out,  the 
antennse  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  formerly  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  antennae  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  or 


EXPANSION  OF  PERFECT  INSECTS.  341 

{ 

i  destroyed  by  external  injuries,  but  might  grow  strong 
I  and  ripen."* 

While  the  little  creature  remains  in  this  condition, 
there  is  produced,  as  Swammerdam  tells  us,  a  vio- 
lent 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  bursting  in  four  distinct  and  regular 
pieces.  When  the  legs  become  disengaged,  they 
iimch  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  circumstance  enables 
the  insect  to  take  more  air  into  its  body,  and  thereby 
renders  it  the  better  able  to  fly,  and  perform  the 
other  functions  dependent  on  a  good  supply  of  air. 
In  consequence  of  this,  the  wings  expand  so  rapidly, 
that  it  is  by  no  means  easy  to  trace  their  unfold- 
ing ;  for  in  the  space  of  a  few  minutes,  they  increase 
in  dimensions  about  five-fold.  Their  spots  and 
colours  at  the  same  time,  previously  so  small  as  to 
be  scarcely  discernible,  become  proportionally  ex- 
tended, so  that  what  but  a  few  minutes  before  ap- 
peared 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 

I  *  Malpighi,  De  Bombyce. 


342  INSECT  TRANSFORMATIONS. 

an  hour,  no  longer  visible,  and  the  insect  becomes 
fitted  for  flight.* 

Kirb)'-,  in  speaking  of  the  swallow-tailed  butterfly 
(Papilio  Machaon ),  says,  "  I  had  the  pleasure  of 
seeing  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  deve- 
loped, and  the  animal  perfect  in  beauty,  I  secured  it, 
though  not  without  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  development  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  interesting  spectacle.  At 
first,  it  was  unable  to  elevate  or  even  move  its  wings ; 
but  in  proportion  as  the  aerial  or  other  fluid  was 
fijrced  by  the  motions  of  its  trunk  into  their  nervures, 
their  numerous  corrugations  and  folds  gradually 
yielded  to  the  action  till  they  had  gained  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  ."t 

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  insect,  folded  up  as  are  the  long 
wings  of  an  earwig  {Forjicula  auricularid)^  but  are 
*  Swammeidain,  ii.  7,  &c.  f  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 
stretched  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  tirst  tried,  we  believe,  by 
Swammerdam,  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  insensibly  and  by  degrees  increase  into  con- 
siderable little  drops." — "  The  wings  of  the  bee  have 
likewise  matiy  pulmonary  tubes,  which,  when  the 
nymph  is  casting  its  last  skin,  have  also,  together 
with  all  the  other  parts,  once  more  to  throw  oft'  their 
exuviae.  After  this,  when  these  tubes  are  again  dis- 
tended by  the  freshly  impelled  air,  and  the  air-vessels, 
which  have  hitherto  been  contracted,  are  inflated  and 
distended  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 
expansion  of  the  wings  depends,  therefore,  both  upon 
the  impulsion  of  the  air  and  of  the  blood;  for  at  the 
same  time  when  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  ])roperly ;  so  that  after 
they  have  burst  from  their  cells  they  may  be  pre- 


344 


INSECT  TRANSFORMATIONS. 


pared  for  swarming  immediately,  if  there  be  a  ne- 
cessity 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  serpen- 
tine form,  w'ithout  filling,  every  branchlet  of  the 
nervures.  Those  who  have  not  paid  attention  to  this 
curious  subject  have  little  conception  of  the  great 
diversity  of  forms  which  are  exhibited  by  the  branch- 
ings of  these  nervures,  not  only  in  diiferent  orders, 
but  even  in  different  species  of  insects.  They  differ, 
indeed,  as  much  in  this  respect  as  the  leaves  of  plants 
do  in  their  mode  of  veining. 


Wings  of  insects :— a,  wing  of  a  beetle  ;  h,  wing  of  an  earwig  ; 
c,  wing  of  a  saw  fly;  d,  wing  of  a  crane-fly  ;  e,  wing  of  a  com- 
mon fly  {Musca)  ;  f,  wing  of  a  midge  {Psychuda). 

*  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  (Alucitidce,  Leach),  of 
which  Stephens  enumerates  twenty-nine  British 
species.  One  of  the  most  common  of  these  is  the 
largewhite  plume  (^Pterophoruspentadadylus,  Leach), 
which  may  be  seen,  during  the  summer,  in  hedges 
and  gardens,  flitting  about  like  a  tuft  of  down,  or  a 
snow-white  feather  dropped  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 
liexadactyla.  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.  Rdaumur,  who  liad 
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  magnifying  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  nou- 
rishment 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.  "  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 

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  exem- 
plified than  in  the  uniformity  of  size  in  the  house-fly 
{Musca  domestica),  among  which  scarcely  one  indi- 
vidual 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   occasi- 
onally found  in  houses,  both  larger  and  smaller  than 
the  Musca  domestica,  but  these  are  of  a  different  spe- 
*   J.  Reniiie  on  the  While  Butterflies  of  Britain,   Mag.  Nat, 
Hist.  vol.  ii.  p.  225. 


348  INSECT  TRANSFORMATIONS. 

cies,  and  not,  as  is  popularly  l)elieved,  the  old  cr 
the  young  of  the  house-fly ;  no  more  than  the  mid- 
summer cockchafer  {Zantheumia  solstitialis.  Leach) 
is  the  young  of  the  common  cockchafer  {MeloLontha 
vulgaris).  It  Avould  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,  "  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  become  dry  and  rigid,  could  not  be  folded  up  in 
the  very  compact  manner  in  which  they  existed  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  and  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  expandmg  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  it  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,  notwithstanding, 
into  a  chrysalis,  which  appeared  healthy  and  well 
formed ;  but  when  the  butterfly  appeared,  though  it 
did  not  dift'er  from  the  usual  appearance,  its  wings 
never  expanded  a  single  hair's  breadth,  and  remained 


350 


INSECT  TRANSFOKMATIONS. 


always  in  the  same  state  as  when  it  issued  from  the  j  i 
chrysalis.* 

c 


a,  Vanessa  wticcB,  with  one  wing  imperfect,  b,  brown-tail  moth. 
Porthesia  aurijlua,  with  shrivelled  wings,  c,  Vanessa  urticce,  willi 
unexpauded  wings. 

It  is  not  a  httle  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  this  period  by  many  butterflies  (  Fa- 
nesscBy  &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.  Mouff'et  tells  us,  from 
Sleidan,  that  in  the  year  1553  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,  t  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 
*  J.  R.  f  Mouftet,  Theatr.  Ins.,  107. 


SHOWERS  OF  BLOOD  EXPLAINED.  35 1 

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  but- 
terflies 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  pro- 
jection. 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. 

x2 


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  Cfadone,  Belluno,  and  Feltri,  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  be- 
tween the  14th  and  15th  of  March,  1823,  in  Calabria, 
in  Abruzzo,  in  Tuscany,  at  Bologna,  and  through  the 
whole  chain  of  the  Apennines. 

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,  WoUaston, 
Bauer,  and  Robert  Brown,  who  all  came  to  the 
conclusion  that  it  was  of  a  vegetable  nature,  but 
differed  as  to  its  botanical  characteristics.  Ur. 
Wollaston  supposed  it  to  be  the  seed  of  some  moss ; 
Mr.  Brown  was  inclined  to  consider  it  an  algse,  re- 
lated to  Trcmella  cruenia,  a  common  native  plant; 


CAUSE  OF  RED   SNOW.  353 

while  Mr.  Bauer  thoijght  it  was  a  fungus  of  the  genus 
Uredo.  Professor  Agardh  refers  it  with  Brown  to 
the  lowest  order  of  aigse,  but  standing  as  a  distinct 
genus  upon  the  very  limits  of  the  animal  and  vege- 
table 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  net  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,  men- 
tions that  it  was  easily  detached  when  placed  under 
water,  and  in  three  days  it  was  converted  into  ani- 
mated 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  globulosa  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  estimated  110,592  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.  Jourri.,  Jan.  1829,  p.  55. 

X  3 


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 
gentlemen,  made  an  excursion  the  24th  July,  1821, 
to  Sowallick  Point,  near  Bushman's  Island,  in  Prince 
Regent's  Bay,  in  quest  of  meteoric  iron.  "  The 
summit  of  the  hill,"  he  says,  "  forming  the  point,  is 
covered  with  huge  masses  of  granite,  whilst  the  side, 
which  forms  a  gentle  declivity  towards  the  bay,  was 
covered  with  crimson  snow.  It  was  evident,  at  first 
view,  that  this  colour  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  colour- 
ing 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  similar  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,  hav- 
ing 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  filletl  with  snow 
*  Loudon's  Encycl.  of  Plants,  Protococtus. 


CAUSE  OF  RED  SNOW.  355 

from  top  to  bottom,  but  which  afforded  no  hiding- 
place  for  these  birds  to  form  their  nests,  presented  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, 
perhaps,  for  the  red  snow  of  the  polar  regions,  it  will 
not  explain  that  of  the  Alps,  the  Apennines,  and  the 
Pyrenees,  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. 


(    356   ) 

Chapter  XV. 

Peculiar  Motiom  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  stagnate, 
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  inter- 
rupting the  nictitation  of  the  eyelids ;  but  if  we  keep 
our  eyes  fixed  for  a  few  minutes  they  become  dry  and 
painful  for  w-ant  of  the  regular  supply  of  moisture 
spread  over  them  by  the  process  of  winking.  Breath- 
ing, again,  being  a  more  important  operation,  cannot 
be  long  interrupted,  without  serious  consequences; 
and  when  the  motion  of  any  of  the  limbs  is  prevented 
by  the  accidental  injury  of  its  joint,  it  usually  shrinks 
and  dwindles  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  mo- 
tions of  insects  are  to  the  due  expanding  of  their 
wdngs  upon  emerging  from  the  pupa  state;  and 
several  remarkable  circumstances  show  that,  inde- 
pendent 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  "motions 
ot  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, — mo- 
tions jneciselv  similar  to  many  of  those  cf  insects 
*  Indod.  vol.  ii.  p.  304. 


MOTIONS  OF  INSECTS.  357 

mentioned  by  them  under  this  head.  The  mode 
j  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  seen  not  only  brushing  its  feet 
upon  one  another  to  rub  ofi"  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  de- 
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  m.i- 
nutes  in  this  preliminary  trimming,  when  it  again 
began  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  exulta- 
tion.*    This  insect  is  figured  at  b,  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 
Phalangia.  The  apparatus  for  this  is  admirably  con- 
trived. In  the  common  garden  geometric  spider 
(Epeii'a  diadema),  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  geo- 
metric spiders,  whose  webs  are  meshed  and  thin; 
while  the  brush  prevails  among  those  which  weave 
thick  webs,  such  as  the  red  spider  {Dysdera  ery- 
ihrina,  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 
m  form  of  a  horse-shoe.t 

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.  +  J.  R. 


MOTIONS  OF  INSECTS. 
9^ 


359 


a,  red  spider  {Dysdera  erythrina).  b,  the  head  of  the  red  spider, 
magnified,  c  c,  the  mandibles,  fringed  on  the  inside  with  hair. 
d,  the  eight  ejes,  in  form  of  a  horse  shoe,  e,  the  head  of  the  gar- 
den spider  {Arane  diadeiTto).  fff,  the  eight  eyes,  g  g,  the  upper 
mandibles,     h,  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-like 
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- 
•^  lutr.  ii.  306. 


360 


INSECT  TRANSFORMATIONS. 


duced,  they  immediately  fly  off*  The  long-legged 
spiders,  popularly  called  shepherds  and  harvest-men 
{Phalangifl{F,  Leach),  have  a  similar  mode  of  ele- 
vating their  legs,  particularly  the  second  pair,  which 
they  move  about  in  all  directions. 


/        ) 


a,  Phalangium  ;  b,  Hydrometra  siagnorum,  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 
wmgs  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  {Hyrphidce)-\  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,  Pluna  gamma^X  &c.)  while  sipping 
*  J.  R.  f  See  p.  4.  %  Seep.  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 
I  several  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  great- 
est power  both  of  filling  their  bodies  with  air  and 
of  expelling  it  again  at  pleasure.  Hence  the  kestril 
{Falco  tinny nculus)  may  be  seen  floating  about  for 
a  considerable  time  without  moving  a  wing,  or  per- 
haps 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  thunderbolt  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  pre- 
viously afloat  in  the  region  of  the  clouds.  Many 
birds  which  prey  on  smaller  game  have  somewhat 
similar  methods  of  poising  and  balancing  their 
bodies,  of  which  the  water-ouzel  (^Cinclus  aquaiicus, 

*  "  Super  est  Haliaetos,"  says  Pliny,  "  clarisslma  oculorum 
acie,  librans  ex  alto  sese,  visoque  in  mari  pisce,  praeceps  in  eum 
ruens,  et  discussis  aquis,  rapiens.'" — Hist.  Nat. 

Y 


362  INSECT  TRANSFORMATIONS. 

Bechstein)  furnishes  a  good  example,  putting  itself 
in  a  constant  state  of  preparation,  jerking  its  pie- 
bald head  up  and  down  as  it  skips  from  stone  to 
stone  of  the  brook,  to  pounce  under  water  upon  the 
first  grub  it  espies  swimming.  In  the  same  way 
the  red-breast  {Sylvia  rubecula)  pops  jerking  about 
when  on  the  look-out  for  caterpillars ;  and  so  habitual 
does  this  become,  that  he  does  not  fail  to  go  through 
the  manceuvre  when  he  pecks  up  a  crumb  at  the  cot- 
tage-door, as  well  as  when  he  pounces  upon  a  cater- 
pillar in  the  woods,  w^here  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  else- 
where with  the  fanning  butterflies  {Vanessce)  just 
alluded  to,  we  can  scarcely  (considering  its  size)  ex- 
pect to  have  attracted  the  notice  of  those  who  pay 
little  attention  to  insects.  We  allude  to  the  vibrating 
fly  (Seioptera  vibrans,  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  trans- 
parent 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  conjecture  which  w'e  had  formed  appeared  to  be 
correct ;  for  though,  when  moving  about  the  glass, 
*  J.  R. 


MOTIONS  OF  INSECTS.  363 

it  vibrated  its  wings  as  much  by  candle-light  as  in 
the  sunshine,  probably  from  the  habit  of  associating 
the  two  movements,  yet,  whenever  it  remained  sta- 
tionary, it  kept  the  wings  motionless.  Had  the 
motion  been  indispensable  to  respiration,  and  analo 
gous  to  the  motion  of  the  gills  of  fish,  or  the  panting 
in  the  anal  scale  of  the  water-louse  {Asellus  aqua- 
ticus,  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  Thomson  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 
(MotacillcB),  when  they  perambulate  the  margm  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  in- 
sects which  seem  to  be  expressive  of  pleasure  when 
they  are  not  stationary,  and  leaving  out  of  consider- 
ation, also,  their  foraging  for  food.  A  familiar  in- 
stance of  what  we  allude  to  occurs  in  the  aerial 
dances  of  the  tipulidan  gnats  and  some  other  insects. 
These  are  performed  not  only  in  summer,  but  fre- 
quently even  in  winter  and  in  the  earlier  months  of 
spring, — in  sheltered  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  winter  dancers  is  called  by 
Harris  the  tell-tale  (Trichocera  hiemalis,  Meigen), 

y2 


364  INSECT  TRANSFORMATIONS. 

a  troop  of  which  may  be  occasionally  seen  gamboling 
in  a  sunny  nook,  though  the  ground  be  covered  with 
snow.  When  the  weather  is  warm  and  mild,  how- 
ever, the  dancing  Tipulidce  prefer  the  decline  of  day ; 
and  we  have  remarked  them  keeping  it  up  as  long 
as  we  could  distinguish  them  between  the  eye  and 
the  waning  light  of  the  Avestern  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  butter- 
fly-net. If  this  be  not  at  hand,  he  may  procure  good 
evidence  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 
induces  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  of  twilight,  hum  their  joy  ?" 

The  Excursion. 

The  evening  gamboling  of  rooks  on  the  wing,  when 


MOTIONS  OF  INSECTS.  365 

they  return  from  their  more  distant  excursions  during 
the  autumn,  may  with  more  certainty  be  referred  to 
this  cause.  White  says,  they  rendezvous  by  thou- 
sands over  Selborne  Down,  wheeUng  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  distinguish  be- 
tween 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  bil- 
lows during  a  gale.* 

The  quickness  of  the  vision  of  tipulidan  gnats,  and 
the  rapidity  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 
shower  of  rain,  whose  drops — bigger  than  their  own 
bodies — if  they  fell  upon  them,  must  dash  them  to  the 
ground  ;f  unless  it  may  be  that  the  drops  glide  olf 
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  aterrimiis,  Meigen)  is  exceedingly  common 
in  the  vicinity  of  London,  appearing  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-grey  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  {Cu!ei  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.  f  Kiiuy  and  Spence,  vol.  ii.  p.  374. 


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  {NotoncctidcB^ 
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   jieculiar   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  (Molobrus  ?),  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  female, 
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;  inso- 
mucli  that,  though  it  was  early  in  March,  we  at  first 
mistook  her  for  the  minute  summer  fly  alluded  to  in 
the  last  paragraph.* 

From  all  we  have  observed,  we  think  it  probable, 
that  notwithstanding  the  apparent  sociality  of  the 
dancing  gnats  (^Vi'puHdcp)^  they  do  not  congregate  in 
consequence  of  any  gregarious  feelings,  or  for  mutual 
assistance ;  but  merely  because  they  are  produced 
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 
difierent  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  par- 
ties of  from  two  to  a  dozen  or  more ;  but  we  have 
very  frequently  seen  an  individual  performing  his  gy- 
rations with  the  same  alacrity  when  alone  as  when 
mingling  with  his  companions.  We  conclude,  there- 
fore, 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  "  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."'!' 

The  following  accomit  of  the  manners  of  tliis 
beetle,  by  Mr.  Knapp,  is  well  worth  extracting; 
though  it  is  much  more  lively  and  interesting  than 
strictly  correct : 

"  Water,  quiet,  still  water,  affords  a  place  of  action 
to  a  very  amusing  little  fellow  {Gyrinus  natator)y 
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.  -j-  Intr.  vol.  ii.  p.  4. 

J  We  have  seen  tliem  throughout  the  severe  winter  of  1829-30. 
S'lioiting  on  the  unfrozen  springs  at  Lee,  in  Kent.     J.  R. 


JIOTIONS  OF  INSECTS.  369 

parties  often  or  a  dozen,  near  the  bank,  where  some 
little  projection  forms  a  ba}^  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- 
llea  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  par- 
ties of  this  nimble  swimmer,  presenting  themselves 
at  these  periods  of  vacancy,  become  insensibly  fa- 
miliar to  his  sight,  and  by  many  of  us  are  not  ob- 
served in  after-life  without  recalling  former  hours, 
scenes  of,  perhaps,  less  anxious  days ;  for  trifles  like 
these,  by  reason  of  some  association,  are  often  remem- 
bered, 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  movmg  in 
oblique,  and  indeed  in  every  other  direction.  Now 
and  then  they  repose  on  the  surface  as  if  fatigued  with 
*  Journal  of  a  Naturalist,  p.  307. 

Y    3 


370  INSECT  TRANSFOllMATIONS. 

their  dances,  and  desirous  of  enjoying  the  full  effect 
of  the  sun-beam  :  if  you  approach,  they  are  instan- 
taneously in  motion  again.  Attempt  to  entrap  them 
with  your  net,  and  they  are  under  the  water  and  dis- 
persed 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.  lis  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- 
acdy  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  larvse  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 

*  Iiitr.  vol.  ii.  p.  372. 


MOTIONS  OF  INSECTS.  371 

jK)ol  chance  to  dry  up  in  summer,  and  force  it  to  emi- 
grate. 

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,  ai-e   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  Alexis,  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  admira- 
ble (  Vanessa  atalanta),  at  these  times,  it  will  assail 
and  drive  away.     There  is  another  small  butterfly, 
the  copper  {LyccEna  Phlceas,  Fabr.),   however,   as 
handsome,  and,  perhaps,  still  more  quarrelsome,  fre- 
quenting too  the  same  station  and  flowers  ;  and  a  con- 
stant 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  the  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  have  never  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 
zigzag  pirouettes  in  the  air,  as  we  see  kittens  or 
puppies  do  on  the  ground,  in  their  more  clumsy  but 
no  less  frolicksome  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  in- 
dividual ;  but  it  is  by  no  means  uncommon  to  see  three, 
and  we  have  observed  as  many  as  five  butterflies,  all 
equally  engaged  in  these  supposed  battles,  and  each 
bouncnig  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. 

*  Jouin,  of  a  Natiualist,  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  sunset 
and  dying  before  sunrise,  are  destined  never  to  be- 
hold the  dawn  of  day, — should  have  so  strong  an  in- 
clination for  any  luminous  object. 

It  is  usually  about  the  middle  of  August  that 
the  ephemerae  of  the  Seine  and  Marne  are  expected 
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  re- 
corded 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  staying  in  the 
boat  till  eight  o'clock  without  seeing  any,  he  resolved, 
as  a  storm  was  foreboding,  to  return.  He  had  pre- 
viously 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  ephemerae  are  here  I  "  He 
immediately  seized  one  of  the  torches  and  ran  to  the 


374  INSECT  TRANSFORMATIONS. 

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  pre- 
paring to  fly,  and  others  already  on  the  wing,  while 
everywhere  under  water  they  were  seen  in  a  greater 
or  less  degree  of  forwardness.  The  threatened  storm 
of  rain  and  lightning  at  length  coming  on,  he  was 
compelled  to  leave  the  interesting  scene ;  but,  to  pre- 
vent the  escape  of  the  insects,  he  had  the  tub  covered 
with  a  cloth.  The  violence  of  the  rain  ceased  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  pro- 
digiously augmented,  and  continued  to  increase  for 
some  time  as  he  stood  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  handsfuls  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. 

"  The  countless  numbers,"  he  says,  "  of  ephemerae 
which  swarmed  over  the  water  can  neither  be  con- 
ceived nor  expressed.  When  snow  falls  thickest  and 
in  the  largest  flakes,  the  air  is  never  so  completely 
full  of  them  as  that  which  we  witnessed  filled  with 
ephemerse.  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  surface 


MOTIONS  OF  INSECTS.  375 

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  com- 
posed of  an  unbroken  string  of  ephemerae,  which  fol- 
lowed 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 
Rt^aumur,  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  Hies 
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  ephemerae  begin 
their  dances  with  the  dawn,  instead  of  waiting  till 
sunset, — rising  and  falling  continually  over  the 
meadows  in  May,  sometimes  beating  the  air  rapidly 
with  their  whigs,  and  sometimes  skimming  about  like 
hawks.t  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.^ 

In  speaking  of  what  appear  to  be  the  sports  of 
insects,  we  cannot  omit  taking  notice  of  the  very  sin- 
gular proceedings  of  some  species  of  ants,  which,  at 
the  intervals  of  busy  industry,  amuse  themselves  with 
something  apparently  analogous  to  our  wrestling  and 
racing  matches.  Bonnet  says  he  observed  a  small 
species  of  ants,  which  employed  themselves  in  car- 
rying each  other  on  their  backs,  the  rider  holding 
with  his  mandibles  the  neck  of  his  bearer,  and  em- 
bracing it  closely  with  his  legs,§  the  position  which 

*  Reaumur,  Mem.  vol.  vi.  p.  485. 

t  Kirby  and  Spence,  vol.  ii.  p.  373.  I   J.  R. 

^  Bonnet,  CEuvres,  vol.  ii.  p.  407. 


MOTIONS  OF  INSECTS.  377 

the  renowned  John  Gilpin  may  have  sometimes 
been  disposed  to  assume  in  his  famous  race  through 
Edmonton.  But  though  the  very  palpable  mis- 
takes 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. '*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  ex- 
ercise, "f 

It  was  amongst  the  same  species,  that  Huber  ob- 
served similar  proceedings,  which  he  has  described 
with  his  usual  minuteness  and  accuracy.  "  I  ap- 
proached," he  says,  "  one  day  to  the  formicary  of 
W'ood-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 
difficulty  ;  but  when  I  examined  the  conduct  of  each 
ant,  I  saw  them  approach  one  another,  moving  their 
antennae  with  astonishing  rapidity,  while  they  patted 
with  a  «light  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  ])p.  211  and  233. 
I  Gould  on  Ants.  p.  102,  ike. 


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  re- 
tain their  opponents  with  that  obstinacy  which  we  ob- 
serve in  their  real  quarrels.  They  presently  aban- 
doned those  which  they  had  first  seized,  and  endea- 
voured 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 
moments,  the  skirmish  only  terminating  when  the 
least  animated,  having  overthrown  his  antagonist, 
succeeded  in  escaping  and  hiding  in  one  of  the  gal- 
leries. In  one  place,  two  ants  appeared  to  be  gambol- 
ling about  a  stalk  of  grass, — turning  alternately  to 
avoid  or  seize  each  other,  which  brought  to  my  recol- 
lection the  sport  and  pastime  of  young  dogs  when 
they  rise  on  their  hind-legs,  attempting  to  bite,  over- 
throw, 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. 


379 


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  disproportionate,  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  opi/io),  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 
those  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  accidently  caught  on  some  straggling 
films  of  spiders'^  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  m.ovement 
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  ad- 
jacent garden  to  the  wall.  Another  occurred  in  the 
same  place  somewhat  similar,  but  considerablv  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  ap- 
pears to  be  the  wandering  plant-bug  (Ploiaria  vaga- 
hunda^  Scopoli). 

Many    insects   are   capable   of  performing   a   feat 

which  no  other  animal  could  accomplish  w'ithout  the 

aid  of  the  water-shoes  lately  invented — we  allude  to 

walking  on   the  water,   as  distinct  from  swimming, 

*  J.  U. 


PECULIAR   MOTIONS  OF  INSECTS.  381 

a  h 


a,  Ploiaria  vagabunda,  magnified,     b,  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  waxj^  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  farther  progress  upwards.  The  most 
common  of  these  are  two  aquatic  bugs  of  different 
genera — the  one  (Gerris  locustris,  Latr.),  with  a 
long  blackish  body  and  legs,  and  white  belly,  though 
more  clumsy  in  form  than  the  water-measurer  {Hij- 
drometra  stagnorumj  formerly  mentioned ;  and  the 
other  (^Velia  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- 
grey  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  in- 
stinctively that  we  cannot  so  easily  pursue  it.  Tliis  is 
not,  however,  the  diving  water-spider  {Argyroneta 
aquaticd)^  for  though  it  can  dive  and  remain  under 
water,  it  does  not  seem  to  relish  this,  except  when 
driven  to  the  measure.* 


h,  Hydrometra  stagnorum.    c,  d,  Hydrachna  Geograpkica,  Latb., 
front  and  back  view,  both  magnified,    e,  Velia  rivulorum,  Latr. 


PECULIAR  MOTIONS  OF  INSECTS.  383 

Some  of  these  water  insects  have  such  slender  feet, 
that  we  can  only  explain  their  not  sinking  in  the  water 
on  the  same  principle  as  that  of  a  small  needle  float- 
ing 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.  Linnse.us  saw 
one  of  these  little  tipulsc,  of  a  black  colour,  performing 
gyrations  on  the  water  similar  to  those  of  the  whirl- 
wig  (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,  Mxjl- 
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  (Trombidium 
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 
aquaticusy  Bechstein),  which  we  have  repeatedly 
seen  walk  deliberately  under  water,  and  continue  its 
pace  for  many  yards,  as  if  it  had  been  'on  land.* 
*  J.  R. 


384  INSECT  TRANSFORMTIONS. 

As  this  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  {Hydwphili^  &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  {Psij- 
chodfF,  Latr.),  instead  of  walking  straight  forwards, 
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  dow-n  a  steep  hill.  It  was  tirst 
observed,  we  believe,  by  Kirby,  that  a  millepede 
common  under  stones,  the  bark  of  trees,  and  the 
hollow  stems  of  decaying  plants,  and  provincially 
called  maggy-m  any  feet  {Jidus  terrestris)  performs 
its  serpent-like  motion  by  extending  alternate  por- 
tions of  its  numerous  legs  beyond  the  line  of  the 
body,  v»^hile  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  ofi'  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  world  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  {Nyderibia  Hermanni,  Leach),  the  legs  ap- 
pear to  have  their  usual  place  on  the  back.  "  It 
transports  itself,"  says  Colonel  Montagu,  "  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." — "  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."t 

Many  of  the  beetles  run  with  great  velocity,  and 

*  J.  R.  f  Linn.  Trans,  vol.  xi.  p.  13. 

Z 


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  hahit  is  observable  among  spiders,  par- 
ticularly 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    \ 


a,  Julus  terrestris.    b,  the  same  coiled  up.     c,  oil-beetle  (Pro- 
scarabeeus  vulgaris),     d,  Nycieribia  Hermanni. 

'■'  Intr.  vol.  ii.  p.  311. 


PECULIAR  MOTIONS  OF  INSECTS.     387 

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  {Proscarabmus  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  1829-30,  we  found  several 
in  the  beginning  of  March  feeding  on  the  bulbous- 
rooted  buttercup  {Ranunculus  bulboavs),  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.  f   lusecl  Architecture,  p.  355. 

z  2 


388  INSECT  TRANSFORMATIONS. 

it  is  furnished  with  feet  most  admirably  contrived  for 
taking  hold  of  the  catchweed  {Galium  Aparine), 
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 
oft',  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.  "  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 — "  Its  ability  to  walk  on  glass,"  says 
S.  Shaw,  "  proceeds  partly  from  some  little  rugged- 
ness  thereon,   but   chiefly  from  a  tarnish,  or  dirty 

*  See  Menageries,  Lib.  of  Kntertaiii.  Knowl.  vol.  i.  p.  173. 
t  Spect.  de  la  Nat.  vol.  i.  p.  116. 


PECULIAR  MOTIONS  OF  INSECTS.  389 

smoky  substance,  adhering  to  the  surface  ;  so  that, 
though  the  sharp  points  on  the  sponges  cannot  pene- 
trate tlie  surface  of  the  glass,  it  may  easily  catch  hold 
of  the  tarnish."*  This  is  evidently  borrowed  from 
Hook.t  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  tarnish  on  glass.  Even  th£  shrewd  Reaumur 
could  not  give  a  satisfactory  explanation  of  the  cir- 
cumstance. 

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  atmoophere — 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." | 
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. 

f  Micrographla,  p.  170. 

I  Physico-Theology,  vol.  ii.  p.  194,  note  (b),  llth  ed. 

§  Nat.  Hist,  of  Selboiue,  vol.  ii.  p.  274. 

z  3 


390  INSECT  TRANSFORMATIONS. 

mentions  "a  very  small  handsome  lizard,  about  a 
finger's  length,  which  climbs  along  the  walls,  and 
even  along  glass,  in  pursuit  of  flies  and  other  in- 
sects ;"*  and  Sir  Joseph  Banks  noticed  another  lizard, 
named  the  gecko  {Lacerta  Gecko^  Linn.)  which 
could  walk  against  gravity,  and  which  made  him  de- 
sirous of  havmg  the  subject  thoroughly  investigated. 
On  mentioning  it  to  Sir  Everard  Home,  he  and  Mr. 
Bauer  commenced  a  series  of  researches,  by  which 
they  proved  incontrovertibly,  that  in  climbing  upon 
glass,  and  walking  along  the  ceilings  with  the  back 
downwards,  a  vacuum  is  produced  by  a  particular 
apparatus  in  the  feet,  sufficient  to  cause  atmospheric 
pressure  upon  their  exterior  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  move- 
able 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. t 

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 
{Pulei  irritans)^  whose  wings  are,  according  to 
Kirby,  obsolescent.     The  structure  of  this  annoying 

*  Voyage  to  the  Isle  of  France,  p.  73. 
t  Philosopli.  Trans,  for  ISIH,  p.  325. 


PECULIAR  MOTIONS  OF  INSECTS. 


391 


Feet  of  the  bluebottle  fly,  maguifieil  6400  times.  A,  a  view  of  the  under 
6ide  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  ihe  hJbio  fflmlia  (Latr.),  magnified  6400  timeg.  A,  the  under 
side  of  the  last  joint  of  the  toe,  with  the  tlirec  suckers  expanded.  B, 
side  view  of  ditto. 


392 


INSECT  TRA.NSFOIIMATIONS. 


creature  is  well  fitted  for  its  mode  of  life — it  being 
furnished  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  extraordn:iary 
muscular  power  of  the  thighs,  again,  combined  with 
their  elasticity,  enables  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  not  possibly  perceive  w^hither 
they  were  leaping.*  It  may  not  be  out  of  place  here  to 
mention,  that  fleas  (Pulicidce)  undergo  similar  trans- 
formations to  other  insects,  laying  their  eggs  at  the 
roots  of  the  hair  of  animals,  the  feathers  of  birds,  or 
in  woollen  stuff's.  These,  in  a  few  days,  produce  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  muscuUr  stjucture  of  the  le; 
*  *  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  dif- 
ferent from  the  common  flea,  and  it  is  probable  these 
will  not  readily  pass  from  their  natural  habit  to  infest 
VIS,  as  is  commonly  believed. 

The  extraordinary  power  of  leaping  in  grasshoppers 
and  their  congeners  is  matter  of  common  observa- 
tions. The  motion  is  effected  by  means  of  very 
strong  muscles  with  which  the  hind-thighs  are  fur- 
shed  ;  and  it  is  a  similar  structure  which  enables 
the  frog-hoppers  {Cercopid(B,  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,  v/hile  others  use  it  to  spring  upon  their  prey. 
Among  the  former  we  may  mention  a  family  of 
small  insects  (Poduridce,  Leach),  some  of  them 
inhabiting  water  or  damp  places,  though  most  of  the 
species  are  found  under  decaying  bark  or  vegetable 
refuse.  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,  hke  so  many  minute  fire-works.  Those  which 
are  solitary  are  much  larger,  among  which  we  may 
mention  the  velvet  spring-tail  (Podiira  hotosericca), 
of  which  we  here  give  a  magnified  figure,  to  show 


394  INSECT  TRANSFOKMATIONS. 

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),  svhose 
zebra  stripes  of  white  and  brown  render  it  easily  dis- 
covered 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  (JMygale  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  al- 
most the  velocity  of  light, — the  eye,  notwithstanding 
the  brilliancy  of  their  metallic  colours,  being  fre- 
quently 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  splended  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 


Mygak  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  voli- 
tant  muscles,  compared  with  ours.  It  would  be  no 
very  difficult  matter  to  give  voluminous  illustrations 
on  this  curious  subject.  A  French  naturalist,  M. 
Chabrier,  has  actually  written  an  elaborate  quarto 
volume,  on  the  flight  of  insects.*  Though  Chabrier 
has  unquestionable  talents  of  the  first  order  for  re- 
search, it  is  unfortunate  that  he  permits  his  fancy  to 
travel  somewhat  beyond  the  boundaries  of  fact ;  and 
to  this,  no  doubt,  we  are  to  ascribe  his  retracting  his 
*  Essai  8ur  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-dorsai,  placed 
obliquely  across  these  for  raising  the  wings.  In  the 
dragon-flies  (LibeUulina),  again,  the  disposition  is 
somewhat  different,  the  sterno-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  elasticity  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  con- 
tributes to  reduce  the  specific  gravity  of  the  insect. 
Besides,  by  enveloping  the  interior  organs,  it  ap- 
pears to  me  intended  to  protect  these  against  the  vio- 
lent motions  of  flight,  and  to  contribute  to  the  ex- 
pansion 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.  a,  part  of  the  belly,  b,  the  cosfo-dorsal  mus- 
cles,    c,  d,  the  sferno-dorsal.     e,  part  of  the  head. 

less  difficult  subject  of  investigation  than  flying  with- 
out wings,  as  is  practised  by  the  gossamer-spider 
{Aranea  obtextrix,  Bechstein),  and  its  congeners. 
\Ve  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  a  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. 

2a 


398  INSECT    TRANSFORMATIONS. 

ner,  for  it  will  not  only  drop  perpendicularly  by 
spinning  a  longer  thread  (it  seldom  tries  to  escape 
by  remounting),  but  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  {Argyroneta  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. 


Syrphns. 


399 

Chapter  XVII. 

Rest  of  Insects. 

Mr.  Brightwell  is  reported  to  have  oiice  observed 
an  individual  living  specimen  of  Haltica  concinna^ 
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  insects 
of  all  orders  and  families.  The  continual  stationary 
appearance,  however,  is,  in  most  of  such  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  insects, 
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  (Goncpteryjc 
Rhamni)  in  our  study,  which  we  were  desirous  of 
*  Kirby  and  Spence,  Intr,  vol.  iv.  p.  193. 
2  a2 


400  INSECT  TRANSFORMATIONS. 

having  deposit  her  eggs  on  a  plant  of  the  buckthorn 
{Bhamnvs  Jrangula),  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 
lifeless,  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 
quiescence  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 
Bell.  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  oflf,  as  if  it  had  to  supply  an  insatiable 


REST  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.!  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  (^Ormthomyia 
avicularid)  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; II  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 ;  ^  and  M.  Chabrier  is  of  opinion 
that  insects  possess  the  power  of  propelling  a  fluid 
into  the  nervures  of  their  wings,  and  withdrawing  it 
at  pleasure,  as  they  are  elevated  or  depressed  ;**  but 


*  See  ])age  139. 

f  See  Cuvier,  Anat.  Comp.  vol.  iv.  p.  478,  &c.     And  Marcel 
de  Serres,  Mem.  du  Mus.  pour  1819. 
X  Lesser,  vol.  ii.  p.  84,  note. 
§De  Geer,  vol.  ii.  p.  505  ;  vol.  vi.  p.  287. 
II  On  the  Microscope,  vol.  i.  p.  130.  ^  Ibid. 

**  Sur  le  Vol  des  Insectes. 


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.  Cams,  is  founded 
on  facts  which  were  shown  and  explained  to  him 
by  the  doctor  himself.  "The  first  insect,"  says 
Mr.  Spence,  "to  which  Dr.  Carus  directed  my 
attention,  was  the  larva  of  ephemera  vulgata  (or  an 
allied  species),  in  which,  near  to  the  bronchiae  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 
w'itli  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  semhlis 
viridis  (the  green  lace-whiged  fly),  in  which  pre- 
cisely the  same  phenomena,  but,  if  possible,  more 
clearly,  were  seen  in  the  nervures  of  the  wdngs  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.  Carus  has  observed  the  same  phenomena  m  the 
wings  of  Semhlis  hilineata,  and  in  the  elytra  (wing- 
cases)  of  Lampyris  noctilvca  (the  glow-worm),  and 
L.  Italica^  as  well  as  in  the  fin-like  appendages  at  the 
tail  of  the  larva  of  Agrion  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  msects, 
agreeably  to  the  original  views  of  Chabrier,  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.,  .Tan.  1S;]0,  p.  19. 
t  See  page  3i.'3. 


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  talking  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 
(^Tipulides),  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- 
w^ard ;  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 
{Gonepteryx  Rhamni),  Mr.  Stephens  tells  us  the  se- 
cond brood  appears  in  autumn,  "  and  of  the  latter," 
he  adds,  "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."t 
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  cold  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. 
•}•  Illustrations,  vol.  i.  p.  9. 


REST  OF  INSECTS.  407 

of  flies  let  loose,  ^vhile  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,  mto  a  cloud  o(  mosquitoes  {Cultcidce).* 
It  has  been  remarked  by  most  \\  riters  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 
rvfa),  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. f 

*  QuartPi-ly  Review,  April,  1^21,  p.  200.  f  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-aut ;  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- 
come 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  wdth  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 


REST  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.  I  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 
iJy  thousands,  and  appear  all  hooked  together.  Is 
this  done  in  order  to  provide  themselves  a  httle  heat  ? 
I  presume  this  to  be  the  case,  but  our  thermometers 
are  not  suflSciently  delicate  to  indicate  if  this  be  really 
the  fact."* 

During  the  frosts  of  1829-30,  we  opened  two 
nests  of  the  yellow  ant  (Formica  jiava)  ^  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 
crustaceous  animals  which  abounded  in  the  trees 
{Onisci,  JulidcB,  &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  Au'i?,  p.  239.     See  also  this  volume,  pages  113  116, 


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  history, 
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. 
"  It  has  been  established,"  he  says,  "with  a  wisdom, 
which  we  cannot  but  admire, — with  which  every- 
thing 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  up- 
wards, without  putting  any  bee  into  motion.  We 
see  the  bees  crowded  and  closely  pressed  one  against 
the  other ;  little  space  then  suffices  for  them."'f — 
Again,  when  mentioning  the  custom  of  putting  bee- 
•    J.  R.  t  Mem.  vol.  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  suflBciently  cold  to  keep  the 
bees  in  that  species  of  torpidity  which  does  away  with 
the  necessity  of  their  eating."*  He  also  says,  posi- 
tively, that  the  milder  the  weather,  the  more  risk 
there  is  of  the  hees  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  provided 
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. t 

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  buz- 
zing as  they  always  do  when  ventilating  the  hive, — 
a  process  which  appears  to  have  been  originally  dis- 
covered by  Huber,  and  of  which,  on  account  of  its 
connexion  with  the  disputed  question  before  us,  we 
shall  give  his  own  description  : — 

"  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  ventilathig 
*  Mem.  vol.  v.  p.  682.  •>■  lb.  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 
opposite  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  over- 
thrown 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. 

"  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 
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  |)lay  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  straws  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  perpen- 
dicular 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  fre- 
quent. His  experiments  were  made  at  three  o'clock, 
the  sun  shining,  and  the  thermometer  in  the  shade 
standing  at  44^"* 

Swammerdam  also  seems  to  indicate  that  bees 
remain  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,  ascending  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.  There- 
fore 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  increase  their 
family. "t 

*  Huber  on  Bees,  p.  -'95.  f  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 
November  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 
insects  and  other  animals,  that  a  high  degree  of  cold 
should  render  them  torpid,  while  they  may  contmue 
active  if  there  should  be  a  certain  degree  of  warmth. 
The  following  observations  by  the  ingenious  Mr. 
Gough,  of  Manchester,  form  an  interesting  illustra- 
tion of  this  curious  subject  with  respect  to  another 
insect. 

"Those,"  says  he,  "who  have  attended  to  the 
manners  of  the  hearth-cricket  {Acheta  domestica) 
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  multi- 
plies 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  temporary  torpidity,  which 
it  can  support  for  a  long  time,  when  deprived  by 
accident  of  artificial  warmth. — I  came  to  the  know- 
ledge of  this  fact,"  continues  Mr.  Gough,  "  by  plant- 
ing 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,  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  mis- 
taken ;  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  retreats.  They 
left  the  chimney  corner  on  the  25th  of  May,  1807, 
after  a  fit  of  very  hot  weather,  and  revisited  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 
recalled  to  a  temporary  existence  by  the  comforts  of 
a  fire."* 

*  Reeve,  Essay  on  the  Torpidity  of  Animals,  p.  84. 


416 


[The  subject  of  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  "  Insect 
Transformations;"  with  directions  for  the  collection 
and  preservation  of  Insects  for  purposes  of  study; 
and  a  popular  account  of  the  various  Systems  of 
Classification.] 


417 


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  tlie  act  of  projection ib. 

8.  Ditto,  immediately  after  projection ib. 

9.  Microscopic  views  of  apple  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.  Egg  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  deposition      .       .    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  apendigaster)    ...        66 

21.  Bee  parasite  (iSty^ops  ilfe/tJte)  ....  ...    67 

22.  Leaf-mining  maggots  and  fly,  four  figures         .....        70 

23.  Gnats  forming  their  egg-boats 74 

24.  Magnified  view  of  the  boat  of  gnats'  eggs 75 

25.  Female  gypsey  moths,  and  modes  oif  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,  magnified,    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 110 


418  ILLUSTRATIONS. 

Page 

3'j,  Abdomen  of  chequered  blow  fly,  opened  and  magnified,  showing 

the  coil  of  young  larvae       .  •  ....  .110 

40.  Coil  of  larvse  of  ditto,  partly  unwound ib. 

4 1 .  Large  grey  blow-fly,  with  the  abdomen  opened,  showing  the  young 

maggots Ill 

42.  Breathing  apparatus  of  the  maggot  of  a  large  grey  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      .         .         124 

46.  Egg  of  the  privet  hawk-moth,  magnified,  showing  the  enclosed 

embryo      ........*•         125 

47.  Caterpillar  of  ditto,  when  grown ib. 

48.  Construction  of  eggs  to  facilitate  the  escape  of  the  larvae,  three 

figures 126 

49.  Supposed  animal  and  vegetable  metamorphoses.         .         .         .131 

50.  Egg  of  the  large  cabbage-butterfly 133 

51.  Embryo  butterflies  as  they  appear  in  the  bodies  of  caterpillars,  two 

figures  ...........     135 

52.  Female  of  the  perfect  cabbage  butterfly ib. 

53.  Magnified  view  of  a  section  of  the  bud  of  a  laburnum.         .         .     136 

54.  Section  of  a  bean-seed ib. 

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  grey  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-v,ingeA  &y  (Vvlucella pl'imata) 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.  Larvse  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  ....     15S 

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  of  the  cossus  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  magnified,  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. 


ILLUSTRATIONS.  419 

Page 

89.  Moth  of  the  angle-shades  moth     ......  194 

90.  Viscera  of  the  fossMS,  two  figures I99 

91.  Caterpillar  of  Vanessa  urticce,  magnified         ....  200 

92.  Intestines  of  ditto  •.......,  ib. 

93.  Intestinal  canals  of  the  caterpillar,  pupae,  and  butterfly,  five  figures  201 

94.  Buff-tip  caterpillar  and  moth  of  ditto,  two  figures.         .          .  204 

95.  Encampment  of  the  caterpillar  of  the  small  ermine  on  the  Siberian 

crab 206 

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  (iVematMS  Caprees)  on  the  osier        .  217 

99.  Caterpillar  of  the  saw-fly  (Se/anrfna  a/m)  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  rujicornis         ...          .....  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  5t6?'o /wrtttZanMs,  six  figures           .         .          .  267 

122.  Transformations  of  the  lady-bird,  six  figures  .         .          .          .  270 

123.  Transformations  of  the  lace-winged  fly  and  syTphus,  five  figures  271 

124.  Caterpillar  of  Vanessa  Antiopa,  three  figures      ....  274 

125.  Suspended  caterpillar  of  Vanessa  Antiopa  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  chrysalis,  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  plumicornis^,  six  figures  .  287 

131.  Pupa  of  chameleon-fly,  three  figures      .....  292 

132.  Pupa  of  lap  pit-moth,  "three  figures 294 

133.  Chvysalis  of  Gmepte7-yx  Rhamiii 300 

134.  VupA  of  Lariajascelina    ........  ib. 

135.  Pupa  of  Sphinx  Ligustri        .......  ib. 

136.  Spiracles  of  pupaj,  two  figures.         ......  302 

137.  Pupae  of  the  gnat  and  Tipula ,  four  figures  .         .         ,  304 

138.  Transformations  of  Chirmomus  plumosus,  four  figures          .          .  305 

139.  Case-fly,  with  the  pupa,  and  the  grate-works  of  the  opening  of 

the  latter,  four  figures .  32 1 


420  ILLUSTRATIONS. 

Page 

140.  Pu-pai  of  Cossus  and  ^geria 323 

141.  The  fly  and  pupa  of  the  ant-lion,  four  figures         ....  335 
1    '.  Transformation  of  the  dragon-fly,  five  figures      ....  337 

J'    .  31ow-fly,  magnified,  two  figures 338 

1     .  Wings  of  insects,  sliowing  the  norvures,  six  figures    .       .       .  344 

I.  Twentj'-plume  moth,  two  figures 345 

>.  White-plume  moth ib. 

147.  Specimens  of  deformed  butterflies  and  moth,  three  figures  .       .  35'.* 

148.  Red  spider,  and  the  head,  magnified,  two  figures        .        .       .  359 

149.  Head  of  the  garden-spider  magnified ib. 

150.  Phalangium S'iO 

151.  Hydrometra  stagnorum,  mK^nif^eA ib. 

152.  p'/omna  m^fafcwnda,  magnified 381 

153.  Neides  elegans^  magnified ib. 

154.  Hydrometra  stagnorum,  natural  size 382 

155.  //ydrac^na  (7eo^rap/t!ca,  magnified,  two  figures         .       .       .       .  ib. 

156.  Velia  rwulm-um ib. 

157.  J«/«s  terrestris,  two  figures 386 

158.  Oil-beetle ib. 

159.  Nycterihia  Hermanni ib. 

160.  Feet  of  the  flv,  greatlv  magnified,  four  figures    .       .       ,  391 

161.  Flea,  magnified        .   ' 392 

162.  Velvet  spring-tail,  magnified 394 

163.  American  spider  (A/?/<;a/e  au)C«/ana)  destroying  a  bird         .       .  395 

164.  Muscular  ribbons  for  moving  the  wings  in  Syrphus  inanis,  mag- 

nified, two  figures 397 

165.  Syrphus 398 


FINIS. 


London  -.—Printed  bv  William  Clowes  and  Sons,  Stamford  Street. 


^^     _^ 


- -,       APR  .  65 

'd'^     N.    MANCHESTER. 
INDIANA