﻿( 
  XXXV 
  ) 
  

  

  and 
  to 
  absolute 
  darkness, 
  but 
  had 
  not 
  been 
  able 
  to 
  obtain 
  any 
  

   results 
  from 
  the 
  experiment. 
  Many 
  more 
  experiments, 
  and 
  

   on 
  many 
  more 
  species 
  belonging 
  to 
  widely-separated 
  families 
  

   among 
  the 
  Lepidoptera, 
  should 
  be 
  tried 
  before 
  sufficient 
  

   materials 
  could 
  be 
  accumulated 
  for 
  a 
  satisfactory 
  explanation 
  

   of 
  these 
  temperature 
  effects 
  ; 
  but 
  in 
  the 
  meantime 
  he 
  ventured 
  

   to 
  suggest 
  that 
  some 
  of 
  them 
  were 
  due 
  to 
  the 
  circumstance 
  

   that 
  a 
  particular 
  temperature 
  was 
  more 
  suitable 
  to 
  health 
  

   and 
  vigour 
  than 
  any 
  other 
  was, 
  and 
  tended 
  consequently 
  to 
  

   produce 
  larger 
  size 
  and 
  greater 
  intensity 
  of 
  colouring 
  and 
  

   markings 
  ; 
  but 
  that 
  this 
  would 
  only 
  account 
  for 
  a 
  small 
  part 
  

   of 
  the 
  effects 
  produced, 
  especially 
  in 
  the 
  seasonally 
  dimorphic 
  

   species 
  ; 
  and 
  in 
  those 
  he 
  had 
  operated 
  on 
  there 
  seemed 
  to 
  be 
  

   what 
  in 
  the 
  absence 
  of 
  further 
  knowledge 
  might 
  be 
  called 
  a 
  

   direct 
  tendency 
  in 
  a 
  low 
  temperature 
  to 
  cause 
  darkness 
  of 
  

   markings. 
  Mr. 
  Merrifield 
  exhibited 
  a 
  large 
  number 
  of 
  

   examples 
  of 
  the 
  temperature 
  effects 
  produced, 
  many 
  of 
  which 
  

   were 
  very 
  striking, 
  and 
  said 
  they 
  would 
  be 
  left 
  for 
  in- 
  

   spection 
  for 
  some 
  time 
  at 
  the 
  Natural 
  History 
  Museum, 
  South 
  

   Kensington. 
  

  

  Mr. 
  E. 
  B. 
  Poulton 
  desired 
  to 
  congratulate 
  Mr. 
  Merrifield 
  

   on 
  the 
  results 
  of 
  his 
  work. 
  He 
  had 
  quite 
  thought 
  that 
  Mr. 
  

   Merrifield 
  was 
  right 
  in 
  his 
  earlier 
  conclusion 
  that 
  the 
  results 
  

   obtained 
  were 
  due 
  to 
  temperature 
  and 
  not 
  colour, 
  as 
  had 
  been 
  

   suggested. 
  In 
  addition 
  to 
  Mr. 
  Merrifield' 
  s 
  convincing 
  de- 
  

   monstration 
  that 
  colour 
  is 
  not 
  concerned, 
  Mr. 
  Poulton 
  wished 
  

   to 
  add 
  that 
  he 
  had, 
  during 
  the 
  past 
  season, 
  tested 
  the 
  moth 
  

   which 
  is 
  more 
  likely 
  to 
  yield 
  positive 
  evidence 
  on 
  this 
  point 
  

   than 
  any 
  other, 
  viz., 
  Gnophos 
  ohscxirata, 
  the 
  imago 
  of 
  which 
  is 
  

   well 
  known 
  to 
  be 
  light 
  upon 
  chalk 
  and 
  dark 
  upon 
  peat. 
  In 
  spite 
  

   of 
  this 
  Mr. 
  Poulton 
  had 
  found 
  that 
  when 
  the 
  mature 
  larvfe 
  

   and 
  the 
  pup^e 
  are 
  subjected 
  to 
  light 
  or 
  to 
  dark 
  surroundings, 
  

   no 
  change 
  is 
  produced 
  in 
  the 
  imagines. 
  So 
  far 
  as 
  the 
  evidence 
  

   goes 
  at 
  present, 
  it 
  is 
  probable 
  that 
  the 
  facts 
  are 
  explicable 
  by 
  

   the 
  operation 
  of 
  natural 
  selection, 
  the 
  light 
  varieties 
  occur- 
  

   ring 
  in 
  places 
  where 
  the 
  dark 
  ones 
  are 
  more 
  conspicuous 
  and 
  

   therefore 
  exterminated, 
  and 
  vice 
  versa. 
  

  

  Prof. 
  Meldola 
  said 
  that 
  it 
  appeared 
  to 
  him 
  that 
  on 
  the 
  

   whole 
  Mr, 
  Merrifield's 
  results 
  gave 
  support 
  to 
  Professor 
  

  

  