﻿12 
  

  

  BRITISH 
  LEPIDOPTEEA. 
  

  

  Tephrosiids 
  bred 
  by 
  Bacot 
  and 
  Riding, 
  that 
  they 
  lost 
  all 
  regularity 
  

   as 
  to 
  the 
  time 
  of 
  emergence 
  and 
  became 
  continuously 
  brooded, 
  i.e., 
  all 
  

   the 
  crosses 
  paired, 
  producing 
  progeny, 
  which 
  again 
  paired, 
  and 
  so 
  on. 
  

   Even 
  the 
  influence 
  of 
  T. 
  crepuscularia 
  (biundularia), 
  one 
  of 
  the 
  most 
  

   regularly 
  single-brooded 
  species 
  in 
  England, 
  was 
  unable 
  to 
  prevent 
  

   this, 
  the 
  broods 
  emerging 
  almost 
  entirely, 
  whilst 
  they 
  appeared 
  capable 
  

   of 
  going 
  on 
  indefinitely 
  so 
  long 
  as 
  food 
  could 
  be 
  provided 
  for 
  the 
  larvae 
  

   (Trans. 
  Ent. 
  Soc. 
  Loud., 
  1898, 
  pp. 
  39-40). 
  

  

  It 
  would 
  appear 
  that, 
  in 
  reciprocal 
  crossings, 
  the 
  sex 
  condition 
  of 
  

   the 
  hybrids 
  depends 
  on 
  the 
  predominating 
  influence 
  exerted 
  by 
  one 
  of 
  

   the 
  parents. 
  In 
  the 
  Tephrosiid 
  hybrids 
  (Trans. 
  Ent. 
  Soc. 
  Lond., 
  1898, 
  

   pp. 
  17 
  et 
  seq.) 
  it 
  was 
  found 
  that 
  certain 
  crossings 
  produced 
  almost 
  entirely 
  

   male 
  offspring. 
  This 
  occurred 
  in 
  the 
  only 
  four 
  fertile 
  crossings 
  

   obtained 
  in 
  which 
  Tephrosia 
  crepuscularia 
  (or 
  its 
  ab. 
  delamerensis) 
  w 
  7 
  as 
  

   the 
  male 
  and 
  T. 
  bistortata 
  the 
  female 
  parent 
  ; 
  two 
  broods 
  of 
  this 
  parentage 
  

   bred 
  by 
  Eiding 
  produced 
  60 
  <^ 
  s 
  and 
  one 
  ill-developed 
  ? 
  ; 
  a 
  third 
  brood 
  

   bred 
  by 
  Bacot, 
  58 
  $ 
  s 
  and 
  no 
  female 
  ; 
  a 
  fourth 
  brood, 
  bred 
  by 
  Riding 
  

   38 
  $ 
  s 
  and 
  no 
  $ 
  . 
  On 
  the 
  other 
  hand, 
  in 
  the 
  reciprocal 
  cross, 
  in 
  

   which 
  T. 
  bistortata 
  w 
  7 
  as 
  the 
  $ 
  , 
  and 
  T. 
  crepuscularia 
  the 
  5 
  , 
  parent, 
  a 
  fair 
  

   share 
  of 
  $ 
  s 
  w 
  T 
  as 
  the 
  result. 
  We 
  have 
  no 
  details 
  as 
  to 
  the 
  exact 
  proportion 
  

   of 
  2 
  s 
  to 
  $ 
  s 
  in 
  Smerinthus 
  hybr. 
  hybridus, 
  but 
  the 
  percentage 
  must 
  

   be 
  a 
  very 
  small 
  one, 
  and 
  Newman 
  informs 
  us 
  that, 
  of 
  a 
  very 
  large 
  

   number 
  of 
  this 
  hybrid 
  bred 
  during 
  the 
  last 
  few 
  years, 
  only 
  3 
  or 
  4 
  

   ? 
  s 
  have 
  appeared, 
  i.e., 
  only 
  about 
  one 
  per 
  cent., 
  and 
  of 
  these 
  

   he 
  notes 
  that, 
  though 
  the 
  antenna? 
  are 
  of 
  $ 
  form, 
  the 
  body 
  

   is 
  not 
  so 
  with 
  regard 
  to 
  size, 
  there 
  appearing 
  to 
  be 
  no 
  ova 
  

   present 
  in 
  them. 
  The 
  great 
  rarity 
  of 
  the 
  reciprocal 
  cross, 
  Amorpha 
  

   hybr. 
  inversa, 
  makes 
  it 
  difficult 
  to 
  draw 
  any 
  comparison, 
  although 
  

   Standfuss 
  goes 
  so 
  far 
  (Handbuch, 
  etc., 
  p. 
  63) 
  as 
  to 
  say 
  that 
  the 
  offspring 
  

   thereof 
  consists 
  of 
  both 
  sexes 
  in 
  normal 
  proportions 
  (but 
  we 
  doubt 
  the 
  

   records, 
  not 
  Standfuss' 
  own, 
  on 
  which 
  this 
  statement 
  is 
  based) 
  [see 
  Ent. 
  

   Rec, 
  xiv., 
  p. 
  191, 
  also 
  antea, 
  vol. 
  iii., 
  pp. 
  395-6] 
  , 
  but 
  the 
  broods 
  of 
  S. 
  

   hybr. 
  fringsi 
  (analogous 
  with 
  S. 
  hybr. 
  hybridus) 
  gave 
  5 
  $ 
  s 
  against 
  45 
  $ 
  s, 
  

   and 
  those 
  of 
  A. 
  hybr. 
  metis 
  (analogous 
  with 
  .4. 
  hybr. 
  inversa), 
  gave 
  only 
  6 
  

   imagines 
  — 
  all 
  $ 
  s. 
  As 
  in 
  A. 
  hybr. 
  metis, 
  Calasymbolus 
  hybr. 
  interf 
  'annus 
  

   has 
  also 
  S. 
  ocellata 
  for 
  the 
  $ 
  parent, 
  and 
  in 
  this 
  also 
  the 
  12 
  specimens 
  

   bred 
  were 
  all 
  $ 
  s. 
  The 
  facts 
  relating 
  to 
  the 
  Malacosomid 
  hybrids 
  are 
  

   also 
  interesting. 
  Of 
  Malacosoma 
  hybr. 
  caradjae 
  in 
  which 
  neustria 
  is 
  

   the 
  $ 
  and 
  franconica 
  the 
  $ 
  parent, 
  $ 
  s 
  only 
  have 
  been 
  reared, 
  

   whilst 
  of 
  Malacosoma 
  hybr. 
  scJiaufussi, 
  in 
  which 
  also 
  neustria 
  is 
  the 
  

   $ 
  parent, 
  but 
  castrensis 
  the 
  $ 
  , 
  an 
  abundance 
  of 
  2 
  s 
  have 
  been 
  rapidly 
  

   produced, 
  whilst 
  the 
  $ 
  s 
  have 
  been 
  very 
  few 
  in 
  number 
  and 
  reared 
  

   from 
  slow 
  r 
  -feeding 
  and 
  weak 
  larvae. 
  Piingeler's 
  results 
  with 
  Fumea 
  

   casta 
  $ 
  x 
  affinis 
  $ 
  , 
  and 
  its 
  reciprocal 
  cross, 
  F. 
  a 
  (finis 
  $ 
  x 
  casta 
  2 
  , 
  

   throw 
  7 
  no 
  light 
  on 
  the 
  subject, 
  both 
  giving 
  only 
  $ 
  s, 
  ? 
  s 
  being 
  quite 
  

   absent 
  from 
  both 
  crossings. 
  Much 
  experimental 
  w 
  r 
  ork 
  is 
  w 
  7 
  anted 
  in 
  

   this 
  direction. 
  

  

  As 
  to 
  the 
  degree 
  of 
  superficial 
  appearance, 
  and, 
  to 
  a 
  certain 
  extent 
  

   also 
  the 
  habits, 
  of 
  hybrids 
  to 
  the 
  parent 
  forms, 
  two 
  so-called 
  laws 
  have 
  

   been 
  formulated 
  by 
  Standfuss 
  (Handbuch, 
  &c.) 
  as 
  follows 
  : 
  — 
  

  

  (1) 
  In 
  reciprocal 
  pairing 
  the 
  male 
  is 
  able 
  to 
  transmit 
  the 
  characters 
  of 
  the 
  

   species 
  in 
  a 
  higher 
  degree 
  than 
  the 
  female. 
  

  

  (2) 
  The 
  final 
  extent 
  of 
  approximation 
  towards 
  the 
  male 
  parent 
  depends 
  on 
  

  

  