﻿28 
  BRITISH 
  LEPIDOPTERA. 
  

  

  2). 
  12 
  $s 
  bred, 
  no 
  J. 
  The 
  markings 
  intermediate 
  between 
  

   those 
  of 
  the 
  two 
  species, 
  following 
  castrensis 
  in 
  that 
  the 
  inner 
  

   transverse 
  line 
  of 
  band 
  makes 
  a 
  small 
  pointed 
  angle 
  into 
  median 
  

   band, 
  just 
  before 
  costa. 
  

  

  3. 
  Malacosoma 
  hybr. 
  penzigi, 
  Tutt 
  (franconica 
  $ 
  x 
  castrensis 
  2 
  ). 
  — 
  

  

  1 
  ? 
  only 
  bred. 
  Traces 
  of 
  the 
  median 
  band 
  of 
  castrensis 
  (always 
  

   absent 
  in 
  franconica) 
  are 
  weakly 
  indicated 
  in 
  the 
  hybrid. 
  The 
  re- 
  

   ciprocal 
  crossing, 
  M. 
  castrensis 
  $ 
  x 
  franconica 
  2 
  > 
  produced 
  two 
  

   batches 
  of 
  eggs 
  from 
  which 
  70 
  and 
  92 
  larvae 
  emerged, 
  but 
  these 
  died 
  

   without 
  eating 
  anything 
  except 
  their 
  own 
  eggshells. 
  

  

  In 
  1901-1902, 
  Bacot 
  successfully 
  reared 
  Malacosoma 
  hybr. 
  schanfussi 
  

   (neustriax 
  castrensis) 
  (Proc. 
  Ent. 
  Soc. 
  Lond., 
  1902, 
  p. 
  vii 
  ; 
  Ent. 
  Rec, 
  

   xiv., 
  p. 
  106), 
  when, 
  from 
  200-300 
  eggs 
  were 
  laid, 
  some 
  of 
  which 
  were 
  

   quite 
  empty, 
  some 
  devoloped 
  embryos, 
  which 
  then 
  died, 
  others 
  

   produced 
  larvae. 
  The 
  young 
  larva? 
  (very 
  like 
  those 
  of 
  M. 
  castrensis), 
  

   after 
  the 
  second 
  moult, 
  divided 
  into 
  two 
  sections: 
  (1) 
  " 
  Forwards," 
  that 
  

   were 
  healthy, 
  fed 
  up 
  at 
  an 
  unprecedentedly 
  rapid 
  rate 
  and 
  produced 
  

   only 
  2 
  imagines. 
  (2) 
  "Laggards," 
  an 
  unhealthy, 
  slow-feeding, 
  

   weakly 
  lot 
  that 
  produced 
  30 
  pupa?, 
  from 
  which 
  7 
  $ 
  s 
  only 
  emerged, 
  

   the 
  other 
  pupa? 
  belonging 
  apparently 
  to 
  the 
  same 
  sex. 
  The 
  last 
  

  

  2 
  emerged 
  three 
  weeks 
  ahead 
  of 
  the 
  first 
  $ 
  and 
  before 
  any 
  $ 
  of 
  

   either 
  of 
  the 
  parent 
  species. 
  In 
  1902, 
  these 
  experiments 
  were 
  continued 
  

   and 
  described 
  more 
  at 
  length 
  (Proc. 
  Ent. 
  Soc. 
  Lond., 
  1903, 
  pp. 
  viii-ix 
  ; 
  

   Ent. 
  Rec, 
  xv., 
  p. 
  134). 
  Again 
  the 
  larva? 
  divided 
  into 
  "forwards" 
  

   and 
  "laggards," 
  the 
  former 
  producing 
  only 
  females, 
  and 
  the 
  latter 
  

   males. 
  By 
  forcing 
  the 
  $ 
  pupa?, 
  however, 
  pairings 
  between 
  $ 
  and 
  2 
  

   schaufussi^yere 
  obtained. 
  The 
  2 
  s 
  went 
  through 
  all 
  the 
  ordinary 
  move- 
  

   ments 
  of 
  egglaying 
  and 
  deposited 
  the 
  ordinary 
  cement 
  without, 
  however, 
  

   laying 
  any 
  eggs. 
  Pairings 
  between 
  $ 
  schanfussi 
  x 
  2 
  castrensis, 
  and 
  

  

  3 
  schanfussi 
  x 
  2 
  neustria 
  were 
  obtained, 
  but 
  only 
  few 
  eggs 
  were 
  

   laid, 
  and 
  these 
  were 
  infertile. 
  The 
  imagines 
  of 
  schanfussi 
  bred 
  in 
  

   1901 
  were 
  remarkably 
  uniform 
  in 
  colour 
  and 
  markings, 
  those 
  in 
  1902 
  

   were 
  particularly 
  variable. 
  Of 
  the 
  1901 
  brood, 
  there 
  were 
  6 
  $ 
  s 
  and 
  44 
  

  

  2 
  s, 
  the 
  $ 
  s 
  with 
  pale 
  forewings 
  and 
  dark 
  hindwings, 
  and 
  showing 
  

   unmistakable 
  traces 
  of 
  both 
  parent 
  species. 
  In 
  the 
  forewings, 
  the 
  

   straightness 
  of 
  the 
  transverse 
  lines 
  follows 
  the 
  $ 
  parent, 
  but 
  there 
  

   is 
  a 
  tendency 
  in 
  some 
  of 
  the 
  specimens 
  for 
  the 
  inner 
  of 
  the 
  two 
  lines 
  

   to 
  turn 
  inwards 
  towards 
  the 
  base 
  of 
  the 
  wing, 
  as 
  in 
  castrensis, 
  instead 
  

   of 
  continuing 
  straight 
  to 
  the 
  outer 
  margin 
  as 
  happens 
  with 
  neustria 
  ; 
  

   they 
  also 
  follow 
  the 
  2 
  parent 
  in 
  showing 
  more 
  or 
  less 
  strongly 
  

   the 
  outer 
  dark 
  shaded 
  band, 
  between 
  the 
  transverse 
  line 
  and 
  the 
  

   margin 
  of 
  the 
  wing 
  (which 
  is 
  developed 
  throughout 
  a 
  long 
  series 
  

   of 
  castrensis, 
  but 
  is 
  present 
  in 
  none 
  of 
  the 
  neustria) 
  ; 
  the 
  dark 
  hind- 
  

   wings 
  are 
  also 
  almost 
  entirely 
  due 
  to 
  the 
  same 
  source, 
  as 
  I 
  have 
  never 
  

   seen 
  a 
  $ 
  of 
  the 
  pale 
  canary- 
  coloured 
  form 
  of 
  the 
  last-named 
  species 
  

   that 
  had 
  dark 
  hindwings, 
  whereas 
  this 
  is 
  the 
  normal 
  arrangement 
  

   in 
  castrensis. 
  The 
  14 
  2 
  s 
  are 
  practically 
  all 
  of 
  one 
  type 
  like 
  the 
  $ 
  s, 
  the 
  

   ground 
  colour 
  being 
  very 
  dark 
  umber-brown 
  with 
  narrow 
  pale 
  

   transverse 
  lines 
  on 
  the 
  forewings 
  ; 
  these 
  are 
  much 
  sharper 
  as 
  well 
  as 
  

   narrower, 
  than 
  is 
  normally 
  the 
  case 
  with 
  castrensis, 
  in 
  which 
  species 
  

   the 
  lines 
  are 
  not 
  only 
  broader, 
  but 
  are 
  suffused 
  as 
  well 
  as 
  at 
  their 
  

   edges. 
  In 
  contour, 
  they 
  rather 
  follow 
  the 
  neustria 
  pattern, 
  but 
  there 
  

   are 
  not 
  wanting 
  traces 
  of 
  the 
  2 
  influence 
  if 
  carefully 
  looked 
  for. 
  

  

  