﻿56 
  BEITISH 
  LEPIDOPTEKA. 
  

  

  parent. 
  [Standfuss 
  explains 
  this 
  by 
  supposing 
  that 
  the 
  two 
  specimens 
  

   of 
  ab. 
  eremita, 
  though 
  externally 
  so 
  much 
  alike, 
  possessed 
  entirely 
  

   different 
  properties 
  in 
  regard 
  to 
  their 
  power 
  of 
  transmission 
  to 
  

   descendants. 
  He 
  looks 
  upon 
  the 
  first 
  eremita 
  as 
  a 
  true 
  sport 
  or 
  aberra- 
  

   tion, 
  and 
  in 
  its 
  case, 
  he 
  says, 
  the 
  rule, 
  already 
  formulated, 
  held 
  good 
  

   as 
  usual. 
  The 
  second 
  eremita 
  (which 
  did 
  not 
  show 
  the 
  particular 
  

   varietal 
  characters 
  so 
  well 
  as 
  some 
  of 
  its 
  own 
  offspring), 
  he 
  considers, 
  

   was 
  a 
  link 
  in 
  the 
  chain 
  leading, 
  by 
  slight 
  variations, 
  to 
  a 
  darker, 
  and, 
  

   presumably, 
  better 
  protected 
  form 
  of 
  monacha, 
  which, 
  under 
  the 
  influence 
  

   of 
  natural 
  selection, 
  is 
  gradually 
  developing 
  itself 
  in 
  certain 
  parts 
  of 
  

   the 
  range 
  of 
  the 
  species; 
  it 
  took 
  rank, 
  therefore, 
  he 
  says, 
  not 
  as 
  an 
  

   aberration, 
  but 
  rather 
  as 
  a 
  member 
  of 
  a 
  local 
  race, 
  and 
  with 
  this 
  its 
  

   behaviour 
  accorded. 
  We 
  consider 
  this 
  a 
  very 
  wide 
  conclusion 
  to 
  draw 
  

   on 
  only 
  two 
  experiments. 
  The 
  immediate 
  ancestry 
  of 
  the 
  two 
  specimens 
  

   of 
  eremita 
  here 
  dealt 
  with 
  may 
  have 
  been 
  entirely 
  different. 
  We 
  are 
  

   inclined 
  to 
  dissent 
  strongly 
  from 
  the 
  sport 
  theory 
  of 
  the 
  dark 
  form 
  

   and 
  the 
  extensive 
  inbreeding 
  experiments 
  of 
  Fletcher 
  and 
  others 
  (the 
  

   results 
  unfortunately 
  not 
  published) 
  suggest 
  a 
  development 
  very 
  

   parallel 
  with 
  doubledayaria, 
  etc.] 
  

  

  Aglia 
  tau. 
  — 
  From 
  1885 
  to 
  1893, 
  Standfuss 
  reared 
  numbers 
  of 
  

   Aglia 
  tau, 
  and 
  named 
  the 
  melanistic 
  specimens 
  lugens. 
  So 
  great 
  was 
  the 
  

   difference 
  in 
  these 
  latter 
  that 
  Bang- 
  Haas 
  called 
  the 
  extreme 
  melanic 
  

   form 
  nigerrima, 
  and 
  Thierry-Mieg, 
  the 
  least 
  melanistic 
  ferenigra 
  ; 
  as 
  a 
  

   matter 
  of 
  fact 
  this 
  latter 
  only 
  exhibits 
  black 
  on 
  the 
  outer 
  margin 
  of 
  

   the 
  wings. 
  Standfuss, 
  in 
  crossing 
  these, 
  notes 
  that 
  he 
  obtained 
  tau 
  

   and 
  all 
  the 
  different 
  transitional 
  forms 
  of 
  lugens 
  (from 
  ferenigra 
  to 
  

   nigerrima), 
  but 
  nothing 
  between 
  tau 
  and 
  ferenigra* 
  has 
  been 
  so 
  

   produced. 
  His 
  experiments 
  work 
  out 
  as 
  follows 
  :— 
  In 
  1888, 
  Standfuss 
  

   crossed 
  lugens 
  $ 
  s 
  (inbred 
  for 
  two 
  generations) 
  with 
  tau 
  5 
  s. 
  From 
  

   these 
  more 
  lugens 
  were 
  obtained 
  in 
  1889, 
  and 
  were 
  used 
  in 
  the 
  follow- 
  

   ing 
  pairings: 
  lugens 
  $ 
  xtau 
  2 
  ; 
  tau 
  J* 
  x 
  lugens 
  2 
  ', 
  lugens 
  $ 
  x 
  lugens 
  2 
  . 
  

   The 
  2 
  tau 
  were 
  in 
  each 
  case 
  of 
  different 
  ancestry 
  to 
  the 
  lugens 
  stock. 
  

   The 
  results 
  were 
  : 
  — 
  

  

  5. 
  Aglia 
  lugens 
  $ 
  xtau 
  $> 
  . 
  — 
  95 
  eggs 
  laid, 
  86 
  imagines 
  reared, 
  

   viz., 
  14 
  $ 
  s 
  and 
  28 
  2 
  s 
  of 
  tau, 
  and 
  31 
  $ 
  s 
  and 
  13 
  2 
  s 
  of 
  lugens. 
  

  

  6. 
  Aglia 
  tau 
  J 
  x 
  lugens 
  2- 
  — 
  82 
  eggs 
  laid, 
  75 
  imagines 
  bred, 
  

   viz., 
  13 
  $ 
  s 
  and 
  25 
  2 
  s 
  of 
  tau, 
  and 
  26 
  $ 
  s 
  and 
  11 
  2 
  s 
  of 
  lugens. 
  

  

  7. 
  Aglia 
  lugens 
  $ 
  x 
  lugens 
  2 
  .— 
  89 
  eggs 
  laid, 
  86 
  imagines 
  bred, 
  

   viz., 
  10 
  $ 
  s 
  and 
  21 
  2 
  s 
  of 
  tau, 
  and 
  34 
  $ 
  s 
  and 
  21 
  2 
  s 
  of 
  lugens. 
  In 
  

   1890, 
  from 
  this 
  brood, 
  two 
  more 
  pairings 
  of 
  <? 
  and 
  2 
  lugens 
  were 
  

   obtained 
  : 
  (a) 
  117 
  eggs 
  were 
  laid, 
  giving 
  102 
  imagines, 
  viz., 
  3 
  $ 
  s 
  and 
  

   8 
  2 
  s 
  of 
  tau, 
  and 
  49 
  $ 
  s 
  and 
  42 
  2 
  s 
  of 
  lugens. 
  (/3) 
  103 
  eggs 
  laid, 
  

   giving 
  87 
  imagines, 
  viz., 
  3 
  $ 
  s 
  and 
  7 
  2 
  s 
  of 
  tau, 
  and 
  46 
  $ 
  s 
  and 
  31 
  2 
  s 
  

  

  * 
  Just 
  as 
  the 
  ? 
  of 
  S. 
  lubricipeda 
  ab. 
  intermedia 
  figured 
  by 
  Standfuss 
  (Hand- 
  

   bitch, 
  etc., 
  pi. 
  viii., 
  fig. 
  12), 
  appears 
  to 
  us 
  a 
  very 
  slight 
  advance 
  on 
  typical 
  lubrici- 
  

   peda, 
  when 
  one 
  considers 
  the 
  character 
  of 
  each 
  parent 
  (e.g., 
  zatima 
  in 
  the 
  cross 
  

   of 
  zatima 
  and 
  lubricipeda), 
  so 
  Aglia 
  tau 
  ab. 
  ferenigra, 
  appears 
  to 
  run 
  somewhat 
  

   close 
  to 
  typical 
  tau 
  when 
  one 
  has 
  to 
  take 
  into 
  account 
  that 
  a 
  strongly-marked 
  

   lugens 
  had 
  been 
  one 
  of 
  the 
  parents. 
  There 
  appears 
  little 
  room 
  for 
  what 
  Standfuss 
  

   calls 
  intermediates 
  between 
  A. 
  tau 
  and 
  ferenigra, 
  or 
  between 
  S. 
  lubricipeda 
  and 
  

   intermedia 
  : 
  certainly 
  nothing 
  in 
  our 
  opinion 
  that 
  betokens 
  discontinuous 
  variation. 
  

   "We 
  should 
  say 
  that 
  pi. 
  viii., 
  figs. 
  12, 
  11, 
  13, 
  14, 
  with 
  a 
  type 
  of 
  lubricipeda 
  in 
  front 
  

   of 
  12 
  ; 
  and 
  5, 
  4, 
  6, 
  7, 
  with 
  a 
  typical 
  c? 
  and 
  ? 
  of 
  tau 
  following 
  7, 
  would 
  make 
  a 
  

   very 
  fair 
  consecutive 
  series. 
  

  

  