﻿MIND 
  OF 
  AN 
  INSECT 
  SNODGEASS 
  401 
  

  

  Positive 
  and 
  negative 
  responses 
  to 
  light 
  by 
  insects 
  have 
  usually 
  

   some 
  relation 
  to 
  the 
  other 
  factors 
  of 
  their 
  general 
  behavior, 
  and 
  

   the 
  nature 
  of 
  the 
  light 
  reflex 
  exhibited 
  by 
  any 
  species 
  may 
  be 
  pre- 
  

   sumed 
  to 
  be 
  an 
  adaptation 
  to 
  the 
  insect's 
  mode 
  of 
  life, 
  to 
  its 
  manner 
  

   of 
  feeding, 
  or 
  to 
  some 
  other 
  specific 
  habit. 
  The 
  daytime 
  seclusion 
  

   by 
  nocturnal 
  species 
  and 
  the 
  activity 
  of 
  diurnal 
  species, 
  however, 
  

   can 
  not 
  in 
  all 
  cases 
  be 
  attributed 
  to 
  differences 
  in 
  their 
  photic 
  re- 
  

   actions. 
  A 
  nocturnal 
  moth 
  that 
  has 
  sat 
  quietly 
  all 
  day 
  in 
  the 
  dark- 
  

   ness 
  of 
  some 
  retreat 
  in 
  a 
  room 
  will 
  come 
  out 
  in 
  the 
  evening, 
  though 
  

   the 
  room 
  is 
  brightly 
  lighted. 
  Some 
  singing 
  Orthoptera 
  confined 
  

   indoors 
  begin 
  their 
  music 
  at 
  a 
  regular 
  time 
  each 
  evening 
  regardless 
  

   of 
  the 
  illumination 
  about 
  them. 
  Such 
  observations 
  have 
  led 
  to 
  the 
  

   idea 
  that 
  the 
  activities 
  of 
  many 
  insects 
  are 
  stinmlated 
  by 
  a 
  periodic 
  

   activity 
  in 
  the 
  nerve 
  centers, 
  dependent 
  on 
  some 
  internal 
  rather 
  

   than 
  on 
  an 
  external 
  excitant. 
  The 
  subject 
  needs 
  further 
  investiga- 
  

   tion, 
  but 
  there 
  is 
  much 
  apparent 
  evidence 
  of 
  periodicity, 
  or 
  rhythm, 
  

   in 
  the 
  activities 
  of 
  insects, 
  correlated 
  with 
  the 
  time 
  of 
  change 
  from 
  

   day 
  to 
  night, 
  which 
  can 
  not 
  be 
  satisfactorily 
  explained 
  as 
  reaction 
  

   to 
  changing 
  light 
  intensity 
  or 
  to 
  temperature. 
  

  

  The 
  experiments 
  of 
  many 
  workers 
  on 
  the 
  " 
  color 
  sense 
  " 
  of 
  insects, 
  

   including 
  those 
  of 
  Plateau, 
  Lubbock, 
  Forel, 
  Turner, 
  Lowell, 
  

   Dobkiewicz, 
  von 
  Frisch, 
  Lutz, 
  and 
  others, 
  leave 
  no 
  doubt 
  that 
  at 
  least 
  

   some 
  of 
  the 
  more 
  highly 
  organized 
  insects 
  distinguish 
  differences 
  of 
  

   color 
  ; 
  that 
  is, 
  they 
  show 
  by 
  their 
  reaction 
  that 
  different 
  wave 
  lengths 
  

   of 
  light 
  have 
  different 
  effects 
  upon 
  them. 
  The 
  honeybee 
  has 
  been 
  

   the 
  principal 
  subject 
  of 
  experiments 
  on 
  insect 
  color 
  vision, 
  and 
  it 
  has 
  

   been 
  demonstrated 
  repeatedly 
  that 
  bees 
  can 
  be 
  trained 
  to 
  associate 
  a 
  

   certain 
  color 
  with 
  food, 
  and 
  that 
  they 
  will 
  return 
  successively 
  to 
  an 
  

   object 
  of 
  the 
  same 
  color 
  in 
  their 
  subsequent 
  search 
  for 
  more 
  food. 
  

   The 
  results 
  of 
  such 
  experiments, 
  as 
  already 
  conceded, 
  can 
  not 
  be 
  

   taken 
  as 
  evidence 
  that 
  bees 
  have 
  color 
  sensations, 
  or 
  if 
  they 
  do, 
  that 
  

   their 
  sensations 
  are 
  the 
  same 
  as 
  ours, 
  and 
  yet, 
  since 
  " 
  red 
  " 
  or 
  " 
  blue 
  " 
  

   or 
  " 
  green 
  " 
  have 
  each 
  a 
  definite 
  physical 
  basis, 
  there 
  is 
  no 
  reason 
  

   why 
  the 
  psychical 
  equivalent 
  of 
  each 
  might 
  not 
  be 
  the 
  same 
  wherever 
  

   produced. 
  

  

  Insects 
  that 
  exhibit 
  the 
  power 
  of 
  color 
  discrimination 
  are 
  not 
  

   generally 
  sensitive 
  to 
  all 
  the 
  colors 
  of 
  the 
  spectrum 
  that 
  we 
  see, 
  most 
  

   species 
  being 
  indifferent 
  at 
  least 
  to 
  certain 
  colors; 
  but 
  on 
  the 
  other 
  

   hand 
  many 
  insects 
  unquestionably 
  react 
  to 
  ultra-violet 
  rays, 
  which 
  

   are 
  entirely 
  invisible 
  to 
  us. 
  It 
  has 
  been 
  shown 
  by 
  Lutz 
  that 
  some 
  

   flowers 
  reflect 
  ultra-violet 
  rays, 
  while 
  others 
  do 
  not, 
  and 
  Lutz 
  has 
  

   pointed 
  out 
  that 
  as 
  a 
  consequence 
  the 
  color 
  scheme 
  of 
  nature 
  must 
  be 
  

   quite 
  different 
  to 
  a 
  creature 
  able 
  to 
  see 
  ultra-violet 
  than 
  it 
  is 
  to 
  us. 
  

  

  