﻿.34 
  Dr. 
  H. 
  Eltringham 
  cm 
  Bvtterfy 
  Vision. 
  

  

  are 
  frequently 
  faulty 
  and 
  the 
  results 
  inconclusive 
  or 
  

   contradictory. 
  

  

  Plateau's 
  conclusion 
  that 
  all 
  flowers 
  might 
  be 
  green 
  

   without 
  their 
  due 
  pollination 
  being 
  interfered 
  with 
  does 
  

   not 
  seem 
  to 
  me 
  to 
  prove 
  that 
  flowers 
  which 
  are 
  not 
  green 
  

   gain 
  no 
  advantage 
  from 
  their 
  different 
  appearance. 
  Such 
  

   observations, 
  however 
  they 
  may 
  affect 
  the 
  question 
  of 
  the 
  

   origin 
  of 
  colours 
  in 
  flowers, 
  seem 
  to 
  prove 
  or 
  disprove 
  

   very 
  little 
  in 
  relation 
  to 
  the 
  insect's 
  power 
  of 
  chromatic 
  

   perception. 
  

  

  Lord 
  Avebury's 
  experiments 
  merit 
  a 
  greater 
  considera- 
  

   tion. 
  He 
  experimented 
  largely 
  with 
  bees. 
  In 
  one 
  case 
  

   he 
  gave 
  a 
  bee 
  a 
  drop 
  of 
  honey 
  on 
  a 
  blue 
  paper, 
  and 
  then 
  

   three 
  feet 
  away 
  placed 
  a 
  similar 
  drop 
  of 
  honey 
  on 
  an 
  

   orange 
  paper. 
  After 
  the 
  bee 
  had 
  had 
  two 
  feeds 
  the 
  papers 
  

   were 
  transposed, 
  but 
  the 
  bee 
  returned 
  to 
  the 
  blue 
  paper. 
  

   After 
  a 
  while 
  the 
  papers 
  were 
  again 
  transposed, 
  and 
  the 
  

   bee 
  returned 
  to 
  where 
  the 
  blue 
  paper 
  had 
  last 
  been, 
  and 
  

   found 
  the 
  orange 
  one. 
  It 
  evidently 
  looked 
  different, 
  as 
  she 
  

   stopped 
  and 
  made 
  for 
  the 
  blue 
  paper 
  again. 
  The 
  author 
  

   thus 
  comments 
  on 
  the 
  experiment 
  : 
  " 
  No 
  one 
  who 
  saw 
  her 
  

   at 
  that 
  moment 
  could 
  have 
  the 
  slightest 
  doubt 
  about 
  her 
  

   perceiving 
  the 
  difference 
  between 
  the 
  two 
  colours." 
  

  

  The 
  experiment 
  does 
  not, 
  however, 
  really 
  prove 
  that 
  the 
  

   bee 
  distinguished 
  the 
  colours. 
  A 
  totally 
  colour-bhnd 
  

   person 
  might 
  be 
  able 
  to 
  separate 
  blue 
  and 
  orange 
  papers, 
  

   not 
  by 
  means 
  of 
  their 
  colours, 
  but 
  through 
  their 
  dift'erent 
  

   luminosity. 
  The 
  same 
  author 
  also 
  carried 
  out 
  a 
  rather 
  

   complicated 
  experiment 
  with 
  honey 
  on 
  slips 
  of 
  glass 
  which 
  

   had 
  coloured 
  paper 
  attached 
  to 
  them. 
  By 
  changing 
  and 
  

   removing 
  these 
  and 
  carrying 
  out 
  the 
  experiment 
  many 
  

   times, 
  he 
  arrived 
  at 
  the 
  conclusion 
  that 
  his 
  bees 
  showed 
  a 
  

   marked 
  preference 
  for 
  blue, 
  then 
  white, 
  and 
  successively 
  

   yellow, 
  red, 
  green, 
  and 
  orange. 
  

  

  The 
  order 
  of 
  the 
  colours 
  is 
  peculiar, 
  especially 
  the 
  position 
  

   of 
  the 
  red. 
  If 
  bees 
  are 
  colour-blind 
  and 
  guided 
  mainly 
  by 
  

   luminosity 
  the 
  yellow 
  and 
  green 
  should 
  have 
  been 
  the 
  most 
  

   conspicuous 
  colours, 
  but 
  we 
  have 
  here 
  the 
  red 
  coming 
  

   between 
  these, 
  a 
  result 
  which 
  would 
  not, 
  I 
  venture 
  to 
  

   suggest, 
  be 
  obtained 
  with 
  a 
  colour-bhnd 
  animal. 
  

  

  That 
  insects 
  are 
  attracteil 
  by 
  the 
  colours 
  of 
  the 
  flowers 
  is 
  

   very 
  improbable, 
  and 
  the 
  theory 
  that 
  flower 
  colour 
  has 
  been 
  

   developed 
  because 
  its 
  attractiveness 
  assists 
  in 
  pollination 
  

   has 
  little 
  foundation. 
  Nevertheless, 
  the 
  colours 
  of 
  flowers 
  

  

  