﻿MONGRELISATION 
  IN 
  LEPIDOPTERA. 
  51 
  

  

  quite 
  identical." 
  Some 
  of 
  the 
  pupa3 
  went 
  over 
  and 
  produced 
  imagines 
  

   in 
  the 
  spring 
  of 
  1894 
  (Tugwell). 
  (y) 
  Eggs 
  also 
  received 
  from 
  Harri- 
  

   son, 
  and 
  50 
  imagines 
  bred 
  in 
  May, 
  1893, 
  all 
  zatima, 
  approaching 
  

   deschangei, 
  with 
  no 
  paler 
  ones. 
  (5) 
  From 
  a 
  pairing 
  of 
  these 
  also, 
  a 
  partial 
  

   second 
  brood, 
  again 
  all 
  zatima, 
  appeared 
  in 
  September, 
  1893, 
  etc. 
  (Porritt). 
  

   [The'result 
  was 
  the 
  same 
  everywhere, 
  all 
  those 
  who 
  had 
  eggs 
  in 
  1892 
  from 
  

   Harrison's 
  stock 
  reared 
  practically 
  pure 
  zatima. 
  For 
  scientific 
  purposes, 
  

   therefore, 
  the 
  insects 
  resulting 
  from 
  these 
  early 
  zatima 
  must 
  be 
  looked 
  

   upon 
  as 
  the 
  progeny 
  of 
  a 
  long 
  inbred, 
  highly 
  specialised, 
  race 
  of 
  this 
  

   form, 
  and, 
  therefore, 
  very 
  different 
  from 
  those 
  since 
  obtained 
  by 
  

   selection 
  in 
  various 
  parts 
  of 
  the 
  country. 
  Later, 
  when 
  crossed 
  with 
  

   ordinary 
  lubricipeda, 
  by 
  various 
  lepidopterists, 
  numerous 
  pale 
  examples 
  

   ■ 
  — 
  intermedia 
  as 
  well 
  as 
  the 
  type 
  — 
  were 
  produced 
  with 
  the 
  dark 
  forms.] 
  

   ( 
  6 
  ) 
  [Pairing 
  in 
  1899, 
  from 
  selected 
  specimens 
  inbred 
  for 
  some 
  genera- 
  

   tions, 
  parents 
  originally 
  from 
  the 
  Lincolnshire 
  coast. 
  Both 
  parents 
  of 
  

   medium 
  zatima 
  forms; 
  fringes 
  and 
  central 
  area 
  of 
  forewings 
  pale; 
  hind- 
  

   wings 
  with 
  only 
  the 
  basal 
  and 
  inner 
  marginal 
  areas 
  pale 
  ; 
  the 
  undersides 
  

   with 
  only 
  fringes, 
  nervures, 
  basal 
  areas, 
  and 
  a 
  few 
  streaks 
  of 
  buff 
  colour 
  

   (the 
  female 
  with 
  a 
  broad 
  streak 
  of 
  the 
  pale 
  ground 
  colour, 
  extending 
  from 
  

   basal 
  area 
  half 
  across 
  the 
  wings, 
  parallel 
  with, 
  and 
  near, 
  the 
  hind 
  margin 
  

   of 
  both 
  wings; 
  this 
  is 
  absent 
  from 
  forewings 
  of 
  $ 
  , 
  well-marked, 
  though 
  

   modified, 
  in 
  the 
  hindwings).] 
  Reared 
  74 
  $ 
  s 
  and 
  74 
  $ 
  s, 
  of 
  which 
  

   1 
  $ 
  and 
  2 
  5 
  s 
  were 
  complete, 
  and 
  1 
  $ 
  and 
  3 
  2 
  s 
  partial, 
  cripples. 
  

   Using 
  the 
  parents 
  (description 
  above) 
  as 
  standards, 
  the 
  upper 
  wing 
  

   characters 
  were 
  classified 
  as 
  follows 
  : 
  — 
  

  

  1. 
  Reversion 
  to 
  lubricipeda 
  form 
  — 
  

  

  Forewings. 
  Hindwings. 
  

   A. 
  — 
  c? 
  s 
  with 
  marked 
  tendency 
  to 
  revert 
  . 
  . 
  . 
  . 
  — 
  . 
  . 
  6 
  

  

  B. 
  — 
  ,, 
  ,, 
  medium 
  ,, 
  ,, 
  .. 
  .. 
  — 
  .. 
  3 
  

  

  C. 
  — 
  ,, 
  ,, 
  slight 
  ,, 
  ,, 
  . 
  . 
  .. 
  5 
  .. 
  5 
  

  

  D. 
  — 
  ,, 
  ,, 
  very 
  slight 
  ,, 
  ,, 
  .. 
  .. 
  5 
  .. 
  13 
  

  

  [Note. 
  — 
  One 
  of 
  the 
  specimens 
  in 
  A, 
  as 
  regards 
  hindwings, 
  shows 
  a 
  reverse 
  

  

  (darkening) 
  tendency 
  on 
  forewing, 
  and 
  another 
  specimen 
  in 
  D 
  exhibits 
  the 
  same 
  

  

  tendency.] 
  

  

  A. 
  — 
  ? 
  s 
  with 
  marked 
  tendency 
  to 
  revert 
  . 
  . 
  . 
  . 
  — 
  . 
  . 
  — 
  

  

  B. 
  — 
  ,, 
  ,, 
  medium 
  ,, 
  ,, 
  .. 
  .. 
  — 
  .. 
  — 
  

  

  C— 
  ,, 
  ,, 
  slight 
  ,, 
  ,, 
  .... 
  — 
  .. 
  4 
  

  

  D.— 
  ,, 
  ,, 
  very 
  slight 
  ,, 
  ,, 
  .... 
  6 
  .. 
  2 
  

  

  [Note. 
  — 
  Two 
  specimens 
  in 
  C, 
  and 
  one 
  in 
  D, 
  have 
  progressive 
  forewings.] 
  

  

  2. 
  Progression 
  from 
  lubricipeda 
  form 
  (i.e., 
  darkening 
  to 
  greater 
  

   extent 
  than 
  parents) 
  — 
  

  

  A. 
  — 
  $ 
  s 
  showing 
  increased 
  darkening. 
  . 
  .. 
  .. 
  12 
  .. 
  7 
  

  

  B.— 
  ?s 
  ,, 
  „ 
  ., 
  20 
  .. 
  29 
  

  

  [Note. 
  — 
  Five 
  of 
  the 
  specimens 
  in 
  A, 
  with 
  progressive 
  forewings, 
  haw 
  rever- 
  

   sionary 
  hindwings; 
  three 
  of 
  B, 
  with 
  progressive 
  forewings, 
  have 
  reversionary 
  

   hindwings.] 
  

  

  The 
  pale 
  hindmarginal 
  streak 
  on 
  the 
  underside 
  of 
  the 
  forewing 
  is 
  

   a 
  distinctive 
  character 
  that 
  may 
  be 
  utilised 
  for 
  the 
  purpose 
  of 
  study, 
  

   the 
  similar 
  mark 
  on 
  the 
  underside 
  of 
  hindwing 
  is 
  too 
  much 
  confused 
  

   with 
  the 
  basal 
  patch. 
  In 
  the 
  brood 
  under 
  discussion 
  the 
  / 
  parent 
  

   had 
  not, 
  and 
  the 
  2 
  parent 
  had, 
  tins 
  mark. 
  The 
  details 
  in 
  tin- 
  respect 
  

   are 
  : 
  — 
  

  

  Weaker 
  than 
  in 
  Stronger 
  than 
  

   Absent. 
  ? 
  parent. 
  in 
  % 
  parent. 
  

  

  1. 
  (? 
  s 
  with 
  pale 
  streak 
  .. 
  19 
  .... 
  85 
  .... 
  IT 
  

  

  2. 
  ?s 
  ,, 
  „ 
  ,, 
  .. 
  28 
  .. 
  .. 
  39 
  .... 
  

  

  