﻿8 
  BRITISH 
  LEPIDOPTERA. 
  

  

  organs. 
  Pierce 
  has 
  shown 
  by 
  dissection 
  (antea, 
  vol. 
  iii., 
  p. 
  390 
  ; 
  Ent. 
  

   Rec, 
  x., 
  pi. 
  iii., 
  fig. 
  4) 
  that 
  the 
  male 
  sexual 
  organs 
  of 
  Smerinthus 
  hybr. 
  

   hybridns 
  are 
  quite 
  normal 
  in 
  structure, 
  although 
  differing 
  from 
  those 
  

   of 
  either 
  parent, 
  thus 
  supporting 
  the 
  examination 
  made 
  by 
  Westwood 
  

   (antea, 
  vol. 
  iii., 
  p. 
  452), 
  whilst 
  those 
  of 
  the 
  2 
  exhibited 
  (mixed 
  up 
  

   with 
  the 
  2 
  lobes) 
  the 
  rudimentary 
  and 
  partially 
  developed 
  organs 
  of 
  

   the 
  $ 
  , 
  the 
  whole 
  apparatus 
  being 
  much 
  smaller 
  than 
  that 
  of 
  the 
  

   parents 
  (Ent. 
  Rec, 
  x., 
  p. 
  189). 
  Although 
  ova 
  were 
  discovered 
  in 
  the 
  

   body, 
  the 
  specimen 
  appeared 
  to 
  be 
  quite 
  incapable 
  of 
  reproduction 
  

   (Pierce, 
  antea, 
  vol. 
  iii., 
  p. 
  453; 
  see 
  also 
  general 
  references 
  to 
  this 
  

   matter, 
  vol. 
  iii., 
  pp. 
  449-453). 
  Among 
  the 
  Malacosomas, 
  too, 
  Standfuss 
  

   states 
  (antea, 
  vol. 
  ii., 
  p. 
  525) 
  that 
  the 
  dozen 
  imagines 
  bred 
  of 
  Mala- 
  

   cosoma 
  hybr. 
  schaufussi 
  " 
  are 
  all 
  2 
  s, 
  or, 
  to 
  speak 
  more 
  correctly, 
  a 
  

   form 
  with 
  the 
  external 
  appearance 
  of 
  2 
  s 
  ; 
  some 
  of 
  these 
  hybrids 
  were 
  

   crippled, 
  and 
  the 
  body 
  of 
  one, 
  on 
  being 
  opened, 
  was 
  found 
  to 
  contain 
  

   the 
  rudiments 
  of 
  an 
  ovipositor 
  and 
  an 
  extraordinarily 
  developed 
  mass 
  of 
  

   fat 
  (a 
  quite 
  unusual 
  occurrence 
  in 
  Lachneid 
  2 
  s)." 
  On 
  the 
  other 
  

   hand, 
  Bacot, 
  in 
  1901 
  and 
  1902, 
  bred 
  both 
  sexes 
  of 
  M. 
  hybr. 
  schaufussi, 
  

   though 
  with 
  an 
  overwhelming 
  preponderance 
  of 
  2 
  s, 
  viz., 
  6 
  $ 
  s 
  and 
  44 
  

   2 
  s 
  (in 
  1901), 
  and 
  6 
  $ 
  s 
  and 
  16 
  2 
  s 
  (in 
  1902), 
  the 
  $ 
  s 
  of 
  1901 
  very 
  uniform 
  

   in 
  appearance 
  with 
  pale 
  fore- 
  and 
  dark 
  hindwings, 
  the 
  2 
  s 
  also 
  very 
  

   uniform, 
  dark 
  umber-brown 
  in 
  colour 
  with 
  narrow 
  pale 
  transverse 
  lines 
  

   on 
  the 
  fore 
  wings. 
  The 
  $ 
  s 
  of 
  1902, 
  on 
  the 
  other 
  hand, 
  were 
  not 
  only 
  

   different 
  from 
  those 
  of 
  1901, 
  but 
  also 
  varied 
  inter 
  se, 
  similarly, 
  of 
  the 
  2 
  s, 
  

   only 
  about 
  one-half 
  were 
  of 
  the 
  1901 
  type, 
  the 
  others 
  tending 
  to 
  lose, 
  

   or 
  having 
  entirely 
  lost, 
  the 
  transverse 
  bars. 
  Although 
  the 
  sexes 
  were 
  

   apparently 
  distinct 
  and 
  the 
  $ 
  s 
  of 
  schaufussi 
  paired 
  with 
  2 
  castrensis 
  

   and 
  ? 
  neustria, 
  the 
  eggs 
  proved 
  infertile. 
  Pairings 
  between 
  $ 
  and 
  

   2 
  schaufussi 
  also 
  were 
  obtained, 
  but 
  the 
  hybrid 
  2 
  s 
  laid 
  no 
  eggs, 
  so 
  

   that 
  both 
  sexes 
  were 
  apparently 
  functionally 
  impotent. 
  A 
  similar 
  

   case 
  in 
  which 
  the 
  external 
  organs 
  of 
  the 
  hybrids 
  appear 
  to 
  be 
  well- 
  

   formed, 
  but 
  the 
  $ 
  s 
  as 
  well 
  as 
  2 
  s 
  fail 
  functionally, 
  is 
  that 
  recorded 
  by 
  

   Oberthivr 
  (Bull. 
  Soc. 
  Ent. 
  France, 
  1897, 
  p. 
  259), 
  in 
  which 
  pairings 
  of 
  

   <? 
  Biston 
  hybr. 
  pilzii 
  were 
  obtained 
  with 
  2 
  -pilzii 
  and 
  2 
  hirtarius, 
  

   and 
  of 
  $ 
  Biston 
  hybr. 
  hunii 
  with 
  2 
  pomonarius 
  and 
  2 
  pilzii. 
  This 
  

   sort 
  of 
  evidence 
  is, 
  however, 
  very 
  unsatisfactory. 
  Much 
  more 
  to 
  the 
  

   point 
  is 
  Standfuss' 
  information 
  with 
  regard 
  to 
  the 
  Saturniid 
  hybrids. 
  

   Of 
  some 
  4000 
  hybrids 
  bred, 
  he 
  observes 
  (Entom., 
  xxxiv., 
  p. 
  11) 
  that 
  he 
  

   reared 
  only 
  two 
  gynandromorphous 
  primary 
  hybrids, 
  one 
  a 
  Saturn 
  ia 
  

   hybr. 
  emiliae, 
  the 
  other 
  a 
  S. 
  hybr. 
  bornemanni. 
  On 
  the 
  other 
  hand, 
  

   of 
  282 
  secondary 
  hybrids 
  reared, 
  27 
  were 
  gynandromorphic 
  and 
  he 
  

   concludes 
  that 
  " 
  the 
  percentage 
  of 
  gynandromorphic 
  specimens 
  among 
  

   primary 
  hybrids 
  is 
  infinitesimal 
  compared 
  with 
  the 
  occurrence 
  among 
  

   secondary 
  hybrids." 
  He 
  concludes 
  that 
  " 
  the 
  degree 
  of 
  fertility 
  of 
  a 
  

   form 
  stands 
  in 
  direct 
  connection 
  with 
  the 
  percentage 
  ef 
  gynandro- 
  

   morphic 
  individuals 
  in 
  its 
  offspring 
  ; 
  the 
  greater 
  the 
  fertility 
  the 
  

   smaller 
  the 
  percentage 
  of 
  gynandromorphic 
  forms 
  and 
  vice 
  versa, 
  

   whilst 
  the 
  degeneration 
  and 
  malformation 
  of 
  the 
  egg-germs, 
  which 
  

   these 
  gynandromorphous 
  forms 
  have 
  been 
  shown 
  by 
  anatomical 
  

   investigation 
  to 
  possess, 
  are 
  directly 
  connected 
  with 
  the 
  appearance 
  of 
  

   secondary 
  sexual 
  characters 
  in 
  male 
  individuals, 
  and 
  vice 
  versa 
  ; 
  the 
  

   occurrence 
  of 
  secondary 
  male 
  characters 
  in 
  female 
  individuals 
  has 
  long 
  

   been 
  known 
  to 
  be 
  a 
  fact." 
  A 
  full 
  summary 
  has 
  already 
  been 
  given 
  

  

  