﻿Cocoon 
  Softening 
  in 
  some 
  Agrotids. 
  437 
  

  

  within 
  it, 
  and 
  that 
  all 
  its 
  efforts 
  were 
  now 
  available 
  for 
  

   breaking 
  through 
  the 
  cocoon— 
  a 
  labour 
  that 
  my 
  examples 
  

   had 
  not 
  to 
  undertake. 
  It 
  is 
  to 
  be 
  regretted 
  that 
  I 
  con- 
  

   centrated 
  my 
  attention 
  so 
  much 
  on 
  the 
  mechanical 
  part 
  

   of 
  the 
  process 
  and 
  neglected 
  to 
  make 
  any 
  chemical 
  examina- 
  

   tion 
  of 
  the 
  fluid, 
  which 
  must, 
  however, 
  have 
  been 
  very 
  

   perfunctory. 
  No 
  doubt 
  a 
  considerable 
  amount 
  of 
  the 
  fluid 
  

   might 
  be 
  collected, 
  if 
  preparations 
  were 
  made 
  for 
  doing 
  so, 
  

   the 
  material 
  being 
  a' 
  good 
  supply 
  of 
  pupae 
  of, 
  say, 
  T. 
  fimbria 
  

   and 
  Agrotis 
  pron.uha, 
  which 
  can 
  easily 
  be 
  obtained 
  in 
  

   quantity. 
  

  

  We 
  have 
  long 
  known 
  of 
  the 
  cocoon-softening 
  fluids 
  of 
  

   Saturniids 
  and 
  Cerurids, 
  and 
  I 
  have 
  reported 
  a 
  similar 
  fluid 
  

   as 
  used 
  by 
  sawflies 
  {Trichiosoma 
  tibiale) 
  ; 
  there 
  are 
  prob- 
  

   ably 
  other 
  records, 
  so 
  that 
  no 
  doubt 
  if 
  observations 
  were 
  

   made 
  it 
  would 
  prove 
  to 
  be 
  a 
  very 
  frequent 
  circumstance. 
  

   I 
  have 
  not, 
  however, 
  been 
  able 
  to 
  find 
  any 
  observations 
  

   reported 
  except 
  those 
  on 
  Saturniids 
  and 
  Cerurids, 
  and 
  

   certain 
  Lasiocampids 
  and 
  Limacodids 
  mentioned 
  by 
  Mr. 
  

   Latter. 
  I 
  may 
  say 
  that 
  in 
  many 
  specimens 
  of 
  Eriogaster 
  

   lanestris 
  and 
  Limacodes 
  iestudo 
  I 
  have 
  reared, 
  I 
  have 
  seen 
  no 
  

   indication 
  of 
  a 
  softening 
  fluid, 
  the 
  Ud 
  of 
  the 
  cocoon 
  being 
  

   broken 
  off 
  by 
  pressure 
  from 
  within 
  at 
  a 
  specially 
  provided 
  

   brittle 
  line, 
  and 
  started 
  in 
  Limacodes 
  by 
  a 
  sharp 
  pupal 
  point. 
  

  

  In 
  1868 
  Trouvelot, 
  in 
  the 
  American 
  Naturalist, 
  vol. 
  i, 
  

   p. 
  34, 
  recorded 
  that 
  the 
  softening 
  of 
  the 
  cocoon 
  by 
  the 
  

   secretion 
  of 
  a 
  fluid 
  by 
  the 
  moth 
  about 
  to 
  emerge 
  was, 
  in 
  the 
  

   case 
  of 
  Telea 
  polypheinus, 
  marked 
  by 
  a 
  distinct 
  pause 
  in 
  the 
  

   movements 
  of 
  the 
  moth 
  between 
  the 
  breaking 
  of 
  the 
  

   chrysahs 
  and 
  the 
  rupture 
  of 
  the 
  cocoon 
  for 
  emergence, 
  a 
  

   pause 
  during 
  which 
  the 
  softening 
  fluid 
  has 
  time 
  to 
  act 
  on 
  

   the 
  adhesive 
  material 
  of 
  the 
  cocoon. 
  

  

  In 
  the 
  case 
  of 
  Aciias 
  lima, 
  Packard 
  (American 
  Natural- 
  

   ist, 
  vol. 
  xii, 
  p. 
  379,1879), 
  described 
  the 
  " 
  cocoon-breaker," 
  

   which, 
  it 
  would 
  appear, 
  was 
  in 
  active 
  use 
  by 
  the 
  moth 
  

   from 
  the 
  moment 
  of 
  rupturing 
  the 
  pupa 
  case, 
  till 
  the 
  moth 
  

   broke 
  through 
  the 
  cocoon, 
  no 
  pause 
  occurring. 
  

  

  Kettlewell 
  recorded 
  precisely 
  similar 
  observations 
  in 
  1907 
  

   (Journal 
  Bombay 
  Nat. 
  Hist. 
  Soc, 
  xvii, 
  p. 
  541) 
  on 
  Actios 
  

   selene, 
  and 
  on 
  Antheraea 
  roylei 
  and 
  Caligula 
  simla. 
  

  

  In 
  Mr. 
  Latter 
  's 
  papers 
  in 
  our 
  Transactions 
  for 
  1892 
  and 
  

   1895, 
  on 
  the 
  emergence 
  of 
  D. 
  vinnla 
  from 
  its 
  cocoon, 
  the 
  

   only 
  definite 
  reference 
  to 
  this 
  point 
  is 
  in 
  1895, 
  p. 
  400, 
  

   where 
  it 
  appears 
  that 
  the 
  insect 
  is 
  active 
  during 
  the 
  whole 
  

  

  