﻿Dr. 
  H. 
  Eltringham 
  on 
  Butterfly 
  Vision. 
  33 
  

  

  second 
  example 
  given 
  by 
  the 
  same 
  author. 
  That 
  the 
  two 
  

   faculties 
  mentioned 
  are 
  in 
  fact 
  quite 
  distinct 
  is 
  shown 
  by 
  

   a 
  third 
  case 
  in 
  which 
  the 
  subject 
  appeared 
  to 
  have 
  the 
  

   sensation 
  of 
  green, 
  but 
  httle 
  or 
  no 
  fundamental 
  sensation 
  

   of 
  hght. 
  

  

  Having 
  thus 
  explained 
  something 
  of 
  the 
  meaning 
  of 
  

   colour 
  vision 
  as 
  applied 
  to 
  our 
  own 
  eyes, 
  to 
  what 
  extent 
  

   can 
  we 
  apply 
  the 
  terms 
  we 
  ordinarily 
  use 
  to 
  the 
  question 
  

   of 
  colour 
  vision 
  in 
  an 
  insect 
  ? 
  Naturally 
  we 
  cannot 
  know 
  

   whether 
  what 
  we 
  call 
  red 
  or 
  blue 
  appears 
  red 
  or 
  blue 
  to 
  a 
  

   butterfly, 
  in 
  the 
  same 
  sense 
  as 
  it 
  does 
  to 
  us. 
  We 
  may, 
  

   I 
  think, 
  leave 
  out 
  of 
  account 
  all 
  philosophical 
  verbiage 
  

   on 
  the 
  subject 
  of 
  whether 
  an 
  insect 
  is 
  or 
  is 
  not 
  a 
  conscious 
  

   organism. 
  Consciousness 
  is 
  probably 
  a 
  matter 
  of 
  degree, 
  

   and 
  though 
  in 
  creatures 
  of 
  lowly 
  cerebral 
  organisation 
  it 
  

   may 
  be 
  reduced 
  to 
  a 
  condition 
  hardly 
  definable 
  by 
  our 
  

   limited 
  imagination, 
  some 
  form 
  of 
  consciousness 
  seems 
  

   postulated 
  in 
  any 
  creature 
  which 
  leads 
  an 
  independent 
  

   and 
  more 
  or 
  less 
  comphcated 
  existence. 
  When 
  therefore 
  

   we 
  ask, 
  can 
  a 
  butterfly 
  distinguish 
  colours 
  ? 
  we 
  mean, 
  does 
  

   it, 
  as 
  a 
  nervous 
  organism, 
  possess 
  the 
  faculty 
  of 
  distin- 
  

   guishing 
  those 
  differences 
  in 
  the 
  quality 
  of 
  hght 
  waves 
  

   which 
  we 
  speak 
  of 
  as 
  colour, 
  in 
  a 
  sense 
  distinct 
  from 
  their 
  

   mere 
  luminosity 
  value 
  ? 
  With 
  butterflies 
  comparatively 
  

   few 
  experiments 
  have 
  been 
  made. 
  With 
  other 
  insects 
  

   such 
  investigations 
  as 
  have 
  so 
  far 
  been 
  recorded 
  have 
  

   naturally 
  been 
  carried 
  out 
  with 
  species 
  in 
  which 
  a 
  colour 
  

   sense 
  might 
  be 
  supposed 
  to 
  be 
  of 
  some 
  use 
  in 
  the 
  creature's 
  

   economy. 
  In 
  nature 
  animals 
  are 
  rarely 
  endowed 
  with 
  

   faculties 
  which 
  are 
  superfluous 
  to 
  their 
  mode 
  of 
  hfe, 
  though 
  

   at 
  the 
  same 
  time 
  we 
  must 
  not 
  too 
  readily 
  assume 
  that 
  any 
  

   given 
  insect 
  can 
  have 
  no 
  use 
  for 
  a 
  sense 
  of 
  colour, 
  since 
  

   there 
  are 
  probably 
  few 
  species 
  of 
  the 
  ultimate 
  details 
  of 
  

   whose 
  life 
  history 
  we 
  have 
  absolute 
  knowledge. 
  

  

  Bees, 
  with 
  their 
  intimate 
  relationships 
  to 
  flowers 
  have 
  

   naturally 
  prompted 
  a 
  considerable 
  measure 
  of 
  research, 
  

   more 
  especially 
  as 
  the 
  theory 
  has 
  been 
  advanced, 
  first 
  by 
  

   Sprengel 
  in 
  1793, 
  that 
  flowers 
  attract 
  insects, 
  and 
  especially 
  

   bees, 
  by 
  their 
  bright 
  and 
  conspicuous 
  colours. 
  H. 
  Muller's 
  

   experiments 
  resulted 
  in 
  the 
  statement 
  that, 
  caeteris 
  paribus, 
  

   a 
  flower 
  will 
  be 
  sought 
  by 
  insects 
  in 
  proportion 
  as 
  it 
  is 
  

   conspicuous. 
  Wery 
  arrived 
  at 
  similar 
  conclusions. 
  Miiller 
  

   also 
  pointed 
  out 
  that 
  the 
  perfume 
  is 
  a 
  powerful 
  attraction. 
  

   Many 
  early 
  researches 
  might 
  be 
  quoted, 
  but 
  the 
  methods 
  

  

  TRANS. 
  ENT. 
  SOC. 
  LOND. 
  1919. 
  — 
  PARTS 
  I, 
  II. 
  (JULy) 
  D 
  

  

  