﻿M0NGRELISATI0N 
  IN 
  LEPIDOPTERA. 
  57 
  

  

  of 
  lugens. 
  These 
  imagines, 
  emerging 
  in 
  1891, 
  had 
  parents 
  and 
  grand- 
  

   parents 
  of 
  the 
  lugens 
  type. 
  It 
  will 
  be 
  observed 
  that 
  the 
  1889 
  pairings, 
  

   lugens 
  $ 
  x 
  tau 
  ? 
  and 
  tau 
  $ 
  x 
  lugens 
  ? 
  , 
  gave 
  roughly 
  about 
  50 
  per 
  

   cent, 
  of 
  each 
  form, 
  with 
  a 
  slight 
  preponderance 
  of 
  forms 
  resembling 
  the 
  

   $ 
  parent 
  — 
  in 
  the 
  first 
  case 
  lugens, 
  in 
  the 
  second 
  case 
  tau. 
  The 
  1889 
  

   pairing 
  of 
  lugens 
  $ 
  and 
  £ 
  , 
  gave 
  36 
  per 
  cent, 
  of 
  tau 
  and 
  64 
  per 
  cent, 
  of 
  

   lugens, 
  whilst, 
  in 
  1890, 
  the 
  proportion 
  of 
  tau 
  fell 
  to 
  a 
  little 
  over 
  11 
  per 
  

   cent, 
  in 
  one, 
  and 
  a 
  little 
  under 
  11 
  per 
  cent, 
  in 
  the 
  other. 
  In 
  each 
  of 
  

   the 
  five 
  cases 
  about 
  twice 
  as 
  many 
  $ 
  s 
  as 
  $ 
  s 
  were 
  of 
  the 
  tau 
  form 
  ; 
  

   so 
  that 
  it 
  appears 
  to 
  be 
  more 
  difficult 
  to 
  transform 
  the 
  £ 
  of 
  A. 
  tau 
  

   than 
  the 
  $ 
  . 
  

  

  8. 
  Amphidasys 
  betularia 
  $ 
  x 
  doubledayaria 
  ? 
  . 
  — 
  (a) 
  Steinert 
  gives 
  

   (Isis, 
  1892, 
  pp. 
  424-427) 
  details 
  of 
  a 
  brood 
  resulting 
  from 
  a 
  £ 
  moth 
  found 
  

   near 
  Dresden, 
  in 
  June, 
  1891 
  (in 
  which 
  he 
  assumes 
  the 
  $ 
  to 
  have 
  been 
  

   of 
  typical 
  form). 
  The 
  result 
  was 
  30 
  $ 
  and 
  45 
  $ 
  betularia, 
  and 
  

   34 
  $ 
  and 
  5Q 
  $ 
  doubledayaria. 
  Two 
  of 
  those 
  classed 
  as 
  betularia 
  

   were 
  darker 
  than 
  ordinary, 
  and 
  were 
  the 
  only 
  intermediates. 
  Stand- 
  

   fuss 
  thinks 
  that 
  these 
  two 
  need 
  not 
  be 
  regarded 
  as 
  owing 
  their 
  darker 
  

   coloration 
  to 
  the 
  cross, 
  but 
  as 
  mere 
  aberrations 
  due 
  to 
  the 
  species 
  

   becoming 
  gradually 
  darker 
  in 
  the 
  district 
  (Handbuch, 
  etc., 
  pp. 
  

   315-316). 
  Standfuss, 
  in 
  our 
  opinion, 
  is 
  far 
  too 
  much 
  inclined 
  to 
  explain 
  

   away 
  intermediates 
  when 
  they 
  occur 
  in 
  these 
  crossings. 
  (j3) 
  A 
  typical 
  

   $ 
  paired 
  with 
  $ 
  doubledayaria 
  taken 
  in 
  cop. 
  in 
  June, 
  1902, 
  at 
  

   Brentwood. 
  The 
  eggs 
  divided 
  between 
  Eobbins 
  and 
  Bacot, 
  the 
  latter 
  

   from 
  his 
  moiety 
  reared 
  232 
  moths 
  in 
  1903, 
  as 
  follows 
  : 
  — 
  

  

  S 
  s 
  118 
  = 
  typical 
  56 
  and 
  doubledayaria 
  62. 
  

   ?s 
  114= 
  ,, 
  67 
  „ 
  „ 
  „ 
  47. 
  

  

  No 
  intermediates 
  were 
  bred. 
  There 
  appeared 
  to 
  be 
  some 
  cross- 
  

   inheritance, 
  the 
  majority 
  of 
  the 
  $ 
  s 
  following 
  the 
  pale 
  J 
  , 
  and 
  the 
  

   majority 
  of 
  the 
  dark 
  $ 
  s 
  following 
  the 
  ? 
  (Bacot). 
  (y) 
  A 
  similar 
  pair 
  

   taken 
  in 
  copula, 
  at 
  Kugeley, 
  in 
  1904 
  ; 
  most 
  of 
  the 
  larvae 
  escaped, 
  but 
  

   40 
  pupae 
  were 
  secured. 
  From 
  these 
  34 
  imagines 
  were 
  bred, 
  May-June, 
  

   1905, 
  all 
  black 
  doubledayaria 
  (Freer, 
  in 
  litt). 
  (5) 
  A 
  pairing 
  of 
  

   betularia 
  x 
  doubledayaria 
  (at 
  Willington), 
  produced 
  eggs, 
  from 
  which 
  only 
  

   15 
  imagines 
  were 
  finally 
  reared, 
  viz., 
  7 
  $ 
  s 
  (1 
  black 
  and 
  6 
  typical) 
  and 
  

   8 
  ? 
  s 
  (6 
  black 
  and 
  2 
  typical) 
  (Smallwood, 
  Ent., 
  xxix., 
  p. 
  222). 
  

  

  9. 
  Amphidasys 
  doubledayaria 
  $ 
  x 
  betularia 
  $ 
  . 
  — 
  (a) 
  Forty 
  years 
  

   ago, 
  Edleston 
  obtained 
  a 
  crossing, 
  and 
  the 
  progeny 
  resulted 
  in 
  some 
  

   remarkably 
  pretty 
  aberrations, 
  forming 
  a 
  connecting 
  link 
  between 
  

   doubledayaria 
  and 
  the 
  type, 
  but 
  far 
  before 
  either 
  as 
  regards 
  beauty 
  

   (Ent., 
  ii., 
  p. 
  150). 
  (p) 
  A 
  pair 
  taken 
  in 
  cop. 
  in 
  1888, 
  in 
  Delamere 
  

   Forest. 
  The 
  progeny 
  showed 
  85 
  per 
  cent, 
  black, 
  15 
  per 
  cent, 
  typical 
  

   (Arkle, 
  Entom., 
  xxii., 
  236). 
  (y) 
  In 
  1903, 
  a 
  <? 
  doubledayaria 
  was 
  taken 
  

   in 
  cop. 
  with 
  a 
  $ 
  betularia, 
  at 
  Woodford 
  ; 
  the 
  results 
  of 
  the 
  imagines 
  

   that 
  emerged 
  in 
  1904 
  were 
  as 
  follows 
  : 
  — 
  

  

  Type. 
  Var. 
  Type. 
  Var. 
  

  

  c?s 
  22 
  21 
  = 
  21% 
  20% 
  

  

  ?s 
  35 
  26 
  34% 
  25% 
  

  

  57 
  47 
  55 
  45 
  

  

  