﻿32 
  BRITISH 
  LEPIDOPTERA. 
  

  

  I. 
  Riding's 
  Experiments 
  : 
  Fertile 
  crossings 
  were 
  obtained 
  of 
  — 
  

  

  1. 
  T. 
  bistortata 
  i 
  x 
  T. 
  ab. 
  delamerensis 
  ? 
  .— 
  a. 
  Paired 
  March 
  11th; 
  ova 
  

   deposited 
  March 
  loth 
  ; 
  hatched 
  April 
  26th 
  to 
  27th. 
  

  

  2. 
  T. 
  ab. 
  delamerensis 
  i 
  x 
  T. 
  bistortata 
  ? 
  . 
  — 
  a. 
  Paired 
  March 
  9th 
  ; 
  ova 
  

   deposited 
  March 
  14th 
  ; 
  hatched 
  April 
  18th 
  to 
  19th.— 
  /3. 
  Paired 
  March 
  9th 
  ; 
  ova 
  

   deposited 
  March 
  13th 
  to 
  14th 
  ; 
  hatched 
  April 
  18th 
  to 
  19th. 
  

  

  3. 
  T. 
  bistortata 
  jxT. 
  crepuscularia 
  ? 
  .—a 
  and 
  ,3. 
  Two 
  pairings 
  on 
  March 
  

   17th; 
  ova 
  deposited 
  March 
  20th 
  to 
  22nd 
  ; 
  hatched 
  April 
  25th 
  to 
  27th. 
  

  

  4. 
  T. 
  crepuscularia 
  $ 
  x 
  T. 
  bistortata 
  ? 
  .—a. 
  Paired 
  March 
  7th; 
  ova 
  deposited 
  

   March 
  16th 
  ; 
  hatched 
  April 
  21st 
  to 
  22nd. 
  /3. 
  Paired 
  March 
  14th 
  ; 
  ova 
  deposited 
  

   March 
  20th 
  ; 
  hatched 
  April 
  22nd 
  to 
  23rd. 
  

  

  Crossings 
  that 
  failed 
  were 
  — 
  (1) 
  T. 
  ab. 
  delamerensis 
  $ 
  x 
  T. 
  bistortata 
  

   $ 
  , 
  two 
  pairings, 
  February 
  28th 
  and 
  March 
  12th. 
  (2) 
  T. 
  crepuscularia 
  $ 
  

   X 
  T. 
  bistortata 
  ? 
  , 
  three 
  pairings, 
  March 
  7th, 
  10th, 
  14th. 
  The 
  results 
  

   of 
  the 
  above 
  crossings 
  were 
  as 
  follows 
  : 
  — 
  

  

  i. 
  Hybrid 
  between 
  j 
  T. 
  bistortata 
  (Clevedon) 
  and 
  ? 
  T. 
  ab. 
  delamerensis 
  

   (York).— 
  No. 
  1 
  in 
  list 
  above. 
  One 
  batch 
  of 
  eggs 
  hatched 
  April 
  26th 
  to 
  27tb, 
  100 
  

   imagines 
  emerged 
  between 
  June 
  12th 
  and 
  October 
  22nd, 
  1897 
  ; 
  48 
  J 
  s 
  and 
  52 
  ? 
  s 
  

   = 
  T. 
  hybr. 
  rides 
  gi-suffusa, 
  n. 
  hybr. 
  

  

  ii. 
  Hybrid 
  beticeen 
  d 
  T. 
  crepuscularia 
  ab. 
  delamerensis 
  (York) 
  and 
  ? 
  T. 
  

   bistortata 
  (Clevedon). 
  — 
  No. 
  2 
  of 
  above 
  list. 
  Two 
  batches 
  of 
  eggs 
  obtained; 
  

   hatched 
  April 
  18th 
  to 
  19th. 
  The 
  two 
  broods 
  were 
  fed 
  up 
  together, 
  the 
  imagines 
  

   exhibited 
  being 
  a 
  mixture 
  of 
  both 
  broods. 
  61 
  imagines 
  were 
  reared 
  (60 
  J 
  s 
  and 
  1 
  

   ? 
  ). 
  These 
  emerged 
  between 
  June 
  12th 
  and 
  September 
  19th, 
  1897 
  = 
  T. 
  hybr. 
  

   bacoti-sttffusa, 
  n. 
  hybr. 
  

  

  These 
  two 
  crosses 
  represent 
  the 
  reciprocal 
  crosses 
  of 
  T. 
  bistortata 
  

   and 
  T. 
  crepuscularia 
  ab. 
  delamerensis. 
  Only 
  1 
  ? 
  occurred 
  in 
  cross 
  ii. 
  The 
  

   percentage 
  of 
  a 
  form 
  approaching 
  ab. 
  delamerensis 
  in 
  the 
  two 
  crossings 
  is 
  

   60 
  and 
  40 
  per 
  cent.respectively 
  ; 
  the 
  crossing 
  in 
  which 
  T.bistortataw&s 
  the 
  

   male 
  parent 
  produced 
  by 
  far 
  the 
  larger 
  and 
  more 
  vigorous 
  offspring. 
  

  

  iii. 
  Hybrid 
  between 
  j 
  T. 
  bistortata 
  (Clevedon) 
  and 
  ? 
  crepuscularia 
  (York). 
  

   — 
  No. 
  3 
  of 
  above 
  list. 
  Two 
  batches 
  of 
  eggs 
  obtained 
  ; 
  hatched 
  April 
  25th 
  to 
  

   27th 
  ; 
  larvae 
  fed 
  up 
  together. 
  121 
  imagines 
  emerged 
  between 
  June 
  17th 
  and 
  

   November 
  3rd, 
  1897. 
  These 
  consist 
  of 
  65 
  d" 
  s 
  and 
  56 
  $ 
  s 
  = 
  T. 
  hybr. 
  kldingi, 
  n. 
  hybr. 
  

  

  iv. 
  Hybrids 
  between 
  s 
  T. 
  crepuscularia 
  (York) 
  and 
  ? 
  T. 
  bistortata 
  (Clevedon). 
  

   — 
  No. 
  4 
  of 
  above 
  list. 
  Two 
  batches 
  of 
  eggs 
  obtained 
  ; 
  hatched 
  April 
  21st 
  to 
  23rd 
  ; 
  

   larvse 
  fed 
  up 
  together, 
  40 
  imagines 
  emerged 
  between 
  June 
  16th 
  and 
  November 
  1st, 
  

   1897. 
  These 
  consist 
  of 
  40 
  males 
  and 
  no 
  female 
  = 
  T. 
  hybr. 
  bacoti, 
  n. 
  hybr. 
  

  

  These 
  crosses 
  iii 
  and 
  iv, 
  are 
  the 
  reciprocal 
  crosses 
  of 
  typical 
  T. 
  

   bistortata 
  and 
  T. 
  crepuscularia. 
  The 
  most 
  noticeable 
  point 
  is 
  that 
  

   cross 
  iii 
  produced 
  47 
  per 
  cent, 
  of 
  females, 
  and 
  cross 
  iv 
  no 
  female. 
  The 
  

   earliest 
  specimens 
  to 
  emerge 
  (of 
  both 
  sexes) 
  were 
  pale, 
  those 
  longest 
  

   in 
  the 
  pupal 
  stage 
  were 
  the 
  darkest. 
  

  

  II. 
  Bacot's 
  experiments 
  : 
  Fertile 
  crossings 
  were 
  obtained 
  of 
  — 
  

  

  1. 
  T. 
  bistortata 
  j 
  x 
  T. 
  ab. 
  delamerensis 
  ? 
  . 
  — 
  Paired 
  March 
  9th. 
  

  

  2. 
  T. 
  ab. 
  delamerensis 
  <? 
  x 
  T. 
  bistortata 
  ? 
  . 
  — 
  Three 
  pairings. 
  a. 
  Paired 
  

   February 
  26th 
  ; 
  ova 
  hatched 
  April 
  6th. 
  /3. 
  Paired 
  March 
  5th. 
  y. 
  Paired 
  March 
  

   9th 
  ; 
  ova 
  hatched 
  April 
  7th. 
  

  

  3. 
  T. 
  bistortata 
  $ 
  x 
  T. 
  crepuscularia 
  ? 
  . 
  — 
  Two 
  pairings, 
  a. 
  Paired 
  March 
  

   9th; 
  ova 
  hatched 
  April 
  8th 
  to 
  9th. 
  i 
  S. 
  Paired 
  March 
  9th 
  ; 
  ova 
  hatched 
  April 
  8th 
  to 
  9th. 
  

  

  4. 
  T. 
  crepuscularia 
  j 
  x 
  T. 
  bistortata 
  ? 
  . 
  — 
  Paired 
  February 
  27th. 
  

   Crossings 
  that 
  failed 
  were 
  — 
  (1) 
  T. 
  crepuscularia 
  $ 
  x 
  T. 
  bistortata 
  $ 
  . 
  

  

  Paired 
  February 
  27th. 
  (2) 
  T. 
  ab. 
  delamerensis 
  $ 
  x 
  T. 
  bistortata 
  $ 
  . 
  

   Paired 
  March 
  4th. 
  The 
  results 
  of 
  the 
  above 
  crossings 
  were 
  as 
  follows 
  : 
  

  

  i. 
  Hybrid 
  between 
  j 
  T. 
  bistortatax 
  ? 
  T. 
  ab. 
  delamerensis. 
  — 
  (Ova 
  received 
  

   from 
  Dr. 
  Riding. 
  They 
  are 
  part 
  of 
  Dr. 
  Riding's 
  cross 
  marked 
  1.) 
  Eggs 
  laid 
  

   March 
  15th 
  ; 
  hatched 
  April 
  26th 
  to 
  27th. 
  21 
  specimens 
  emerged 
  — 
  11 
  males, 
  10 
  

   females 
  = 
  T. 
  hybr. 
  hidingi-suffusa, 
  n. 
  hybr. 
  

  

  ii. 
  Hybrid 
  between 
  $ 
  T. 
  ab. 
  delamerensis 
  x 
  ? 
  T. 
  bistortata. 
  — 
  No. 
  2a 
  above. 
  

  

  i 
  

  

  