﻿398 
  ANNUAL 
  KEPORT 
  SMITHSONIAN 
  INSTITUTION, 
  1927 
  

  

  reasonable 
  to 
  suppose 
  that 
  it 
  becomes 
  functional 
  in 
  connection 
  with 
  

   the 
  development 
  of 
  the 
  differential 
  mechanism 
  in 
  the 
  nervous 
  system 
  

   that 
  allows 
  the 
  individual 
  to 
  modify 
  its 
  behavior 
  according 
  to 
  the 
  

   exigencies 
  of 
  circumstances. 
  With 
  consciousness 
  once 
  in 
  possession 
  

   of 
  a 
  mechanism 
  of 
  its 
  own, 
  its 
  development 
  has 
  only 
  been 
  a 
  matter 
  

   of 
  elaboration 
  in 
  the 
  mechanism. 
  From 
  the 
  first 
  fruits 
  of 
  awareness 
  

   in 
  the 
  form 
  of 
  differential 
  perception, 
  which 
  is 
  the 
  beginning 
  of 
  

   intelligence, 
  and 
  of 
  memory, 
  which 
  makes 
  intelligence 
  useful, 
  there 
  

   have 
  been 
  evolved, 
  along 
  with 
  the 
  development 
  of 
  the 
  nerve 
  mecha- 
  

   nism 
  of 
  individual 
  response, 
  all 
  those 
  activities 
  of 
  consciousness 
  that 
  

   we 
  call 
  the 
  mental 
  faculties, 
  and 
  which 
  in 
  ourselves 
  we 
  feel 
  can 
  not 
  be 
  

   identified 
  with 
  any 
  other 
  property 
  or 
  activity 
  of 
  matter. 
  

  

  To 
  limit 
  our 
  conception 
  of 
  the 
  "mind" 
  to 
  conscious 
  activities, 
  as 
  

   suggested 
  above, 
  is 
  permissible 
  as 
  a 
  theory; 
  but 
  since 
  it 
  is 
  possible 
  

   that 
  a 
  closer 
  analysis 
  of 
  animal 
  behavior 
  will 
  show 
  that 
  the 
  facts 
  do 
  

   not 
  conform 
  with 
  the 
  conception, 
  our 
  discussion 
  will 
  be 
  more 
  com- 
  

   plete, 
  and 
  will 
  better 
  meet 
  the 
  emergency, 
  if 
  it 
  is 
  widened 
  to 
  include 
  

   a 
  brief 
  review 
  of 
  some 
  of 
  the 
  more 
  important 
  so-called 
  sensory 
  

   reactions 
  of 
  insects, 
  which 
  are 
  almost 
  certainly 
  automatic, 
  and 
  an 
  

   examination 
  of 
  the 
  nature 
  of 
  insect 
  instincts, 
  as 
  well 
  as 
  examples 
  of 
  

   acts 
  that 
  may 
  reasonably 
  be 
  regarded 
  as 
  intelligent. 
  

  

  II. 
  REACTIONS 
  OF 
  INSECTS 
  TO 
  ENVIRONMENTAL 
  STIMULI 
  

  

  Insects 
  in 
  general 
  are 
  affected 
  by 
  all 
  the 
  classes 
  of 
  things 
  in 
  nature 
  

   that 
  act 
  as 
  sensory 
  stimuli 
  on 
  us, 
  though 
  every 
  species 
  is 
  not 
  receptive 
  

   to 
  all 
  stimuli, 
  and 
  the 
  effect 
  of 
  a 
  particular 
  stimulus 
  varies 
  in 
  kind 
  

   and 
  in 
  degree 
  with 
  different 
  species. 
  

  

  In 
  experimental 
  studies 
  on 
  the 
  so-called 
  " 
  senses 
  " 
  of 
  insects 
  we 
  can 
  

   determine 
  only 
  what 
  the 
  insect 
  does 
  in 
  the 
  presence 
  of 
  conditions 
  that 
  

   give 
  us 
  a 
  sensory 
  impression. 
  If 
  an 
  insect 
  goes 
  to 
  a 
  certain 
  odor, 
  

   and 
  avoids 
  another, 
  the 
  mere 
  fact 
  of 
  the 
  reaction 
  is 
  all 
  that 
  we 
  learn 
  

   from 
  the 
  observation 
  ; 
  by 
  varying 
  the 
  conditions 
  of 
  the 
  experiment 
  we 
  

   may 
  discover 
  less 
  obvious 
  facts, 
  or 
  find 
  relations 
  between 
  external 
  

   things 
  and 
  the 
  reaction 
  that 
  were 
  not 
  suspected, 
  but 
  we 
  can 
  not 
  tell 
  

   what 
  goes 
  on 
  within 
  the 
  insect. 
  Hence, 
  though 
  it 
  may 
  be 
  demon- 
  

   strated 
  that 
  an 
  insect 
  reacts 
  decisively 
  to 
  the 
  stimulus 
  of 
  light, 
  color, 
  

   odor, 
  taste, 
  sound, 
  or 
  touch, 
  we 
  are 
  unable 
  to 
  say 
  literally 
  that 
  it 
  sees, 
  

   smells, 
  tastes, 
  hears, 
  or 
  feels, 
  for 
  these 
  words 
  imply 
  states 
  of 
  con- 
  

   sciousness 
  known 
  only 
  in 
  ourselves. 
  We 
  may 
  say 
  simply 
  that 
  the 
  

   insect 
  is 
  sensitive 
  to 
  this 
  or 
  that 
  stimulus; 
  whether 
  its 
  sensitiveness 
  

   is 
  mere 
  physiological 
  sensitivity, 
  or 
  sensitivity 
  accompanied 
  by 
  con- 
  

   sciousness 
  must 
  be 
  left 
  an 
  open 
  question. 
  On 
  the 
  other 
  hand, 
  no 
  one 
  

   can 
  claim 
  that 
  the 
  facts 
  learned 
  from 
  experiment 
  give 
  reasons 
  for 
  

   denying 
  consciousness 
  to 
  insects, 
  and, 
  as 
  stated 
  before, 
  a 
  belief 
  in 
  the 
  

  

  