﻿MONGRELISATION 
  IN 
  LEPIDOPTERA. 
  65 
  

  

  together, 
  several 
  Jiavofasciata 
  appeared 
  in 
  the 
  progeny. 
  Some 
  of 
  these 
  

   were 
  then 
  paired 
  with 
  normal 
  $ 
  grossulariata, 
  presumably 
  of 
  different 
  

   stock, 
  and 
  again 
  no 
  Jiavofasciata 
  appeared. 
  In 
  1904, 
  Eaynor 
  and 
  

   Doncaster 
  had 
  gone 
  further 
  with 
  regard 
  to 
  the 
  question 
  of 
  heredity 
  

   and 
  sex 
  determination 
  in 
  these 
  crosses, 
  and 
  gave 
  the 
  following 
  

   summary 
  to 
  date 
  : 
  — 
  The 
  ab. 
  Jiavofasciata 
  is 
  recessive 
  in 
  the 
  Mendelian 
  

   sense, 
  not 
  appearing 
  at 
  all 
  in 
  the 
  first 
  cross. 
  In 
  the 
  offspring 
  of 
  

   heterozygotes 
  paired 
  together, 
  half 
  the 
  females 
  are 
  Jiavofasciata, 
  the 
  

   remainder 
  of 
  the 
  females, 
  and 
  all 
  the 
  males, 
  being 
  normal 
  grossu- 
  

   lariata, 
  e.g., 
  the 
  numbers 
  bred 
  in 
  one 
  family 
  of 
  this 
  class 
  were 
  25 
  

   normal 
  $ 
  s, 
  14 
  normal 
  $ 
  s, 
  9 
  fiavofasciata 
  2 
  s 
  ; 
  in 
  another, 
  22 
  normal 
  

   $ 
  s, 
  9 
  normal 
  5 
  s, 
  11 
  Jiavofasciata 
  ? 
  s 
  (1). 
  When, 
  however, 
  & 
  fiavofasciata 
  

   2 
  is 
  paired 
  with 
  a 
  first 
  cross 
  $ 
  (namely, 
  F? 
  x 
  G(F) 
  $ 
  ), 
  among 
  the 
  

   offspring 
  not 
  only 
  some 
  of 
  the 
  females, 
  but 
  also 
  some 
  of 
  the 
  males, 
  

   are 
  Jiavofasciata 
  (2). 
  The 
  numbers 
  available 
  are 
  not 
  yet 
  enough 
  to 
  

   determine 
  with 
  certainty 
  what 
  are 
  the 
  proportions 
  ; 
  in 
  one 
  family 
  

   there 
  were 
  10 
  normal 
  and 
  6 
  fiavofasciata 
  $ 
  s, 
  4 
  normal 
  and 
  2 
  Jiavofasciata 
  

   2 
  s. 
  The 
  facts 
  may 
  be 
  summarised 
  in 
  genealogical 
  tables 
  thus 
  : 
  — 
  

   1. 
  F 
  ? 
  xGcT 
  

  

  I 
  

  

  I 
  - 
  I 
  

  

  G(F) 
  ? 
  x 
  G(F) 
  <? 
  

  

  I 
  l 
  I 
  

  

  IF? 
  1G(F) 
  ? 
  2G 
  <?( 
  = 
  probably 
  1G(F) 
  c? 
  +1GG 
  <s 
  ) 
  

  

  2. 
  F? 
  xGc? 
  

  

  G(F)<? 
  xF? 
  

  

  i 
  i 
  i 
  i 
  

  

  F? 
  G(F)? 
  F<? 
  G(F)<? 
  

  

  The 
  experiments 
  are 
  of 
  importance 
  in 
  relation 
  to 
  Castle's 
  hypo- 
  

   thesis 
  that 
  gametes 
  bear 
  one 
  or 
  the 
  other 
  sex, 
  and 
  that 
  certain 
  somatic 
  

   characters 
  may 
  be 
  coupled 
  with 
  a 
  given 
  sex 
  in 
  the 
  gametes. 
  The 
  

   hypothesis, 
  if 
  somewhat 
  modified, 
  is 
  in 
  excellent 
  accord 
  with 
  the 
  facts; 
  

   but, 
  until 
  we 
  know 
  the 
  result 
  of 
  the 
  pairing 
  Jiavofasciata 
  $ 
  x 
  cross- 
  

   bred 
  2 
  , 
  it 
  would 
  be 
  premature 
  to 
  draw 
  far-reaching 
  conclusions. 
  

   [Explanation 
  of 
  exhibit 
  at 
  the 
  meetings 
  of 
  the 
  British 
  Association, 
  

   Cambridge, 
  1904.] 
  

  

  12. 
  Abraxas 
  grossulariata 
  ab. 
  flavofasciata 
  $ 
  x 
  flavofasciata 
  

   $ 
  . 
  — 
  In 
  July, 
  1904, 
  $ 
  s 
  of 
  ab. 
  flavofasciata 
  were 
  bred 
  for 
  the 
  first 
  time. 
  

   One 
  was 
  paired 
  with 
  a 
  $ 
  of 
  same 
  aberration. 
  Of 
  the 
  progeny, 
  18 
  

   imagines 
  were 
  reared 
  in 
  1905, 
  all 
  of 
  the 
  ab. 
  jiavofasciata 
  (Raynor, 
  

   Ent. 
  llec, 
  October, 
  1905). 
  

   VI. 
  Crossing 
  of 
  typical 
  forms 
  with 
  possible 
  constitutional 
  

  

  ABERRATIONS. 
  

  

  These 
  crossings, 
  as 
  may 
  be 
  supposed, 
  appear 
  to 
  fail 
  almost 
  entirely 
  

   in 
  carrying 
  on 
  the 
  special 
  aberrational 
  forms 
  apparently 
  duo 
  to 
  

   constitutional 
  weakness, 
  i.e., 
  the 
  latter, 
  -per 
  se, 
  is 
  not 
  handed 
  on 
  to 
  

   the 
  progeny, 
  but 
  must 
  be 
  engendered 
  anew 
  by 
  fresh 
  abnormal 
  and 
  

   unsatisfactory 
  conditions. 
  Standfuss 
  notes 
  that 
  the 
  crossing 
  of 
  typical 
  

   Issoria 
  lathonia, 
  Gastropacha 
  t 
  rem 
  nli 
  folia, 
  and 
  Agrotis 
  linogrisea 
  t 
  with 
  

   aberrational 
  forms 
  of 
  the 
  respective 
  species, 
  resulted 
  in 
  no 
  aberrative 
  

   individuals 
  in 
  the 
  progeny 
  (Insekten 
  Bbrse, 
  \i\., 
  p. 
  lt>;>). 
  Other 
  

  

  