﻿ANIMAL 
  BEHAVIOUR 
  203 
  

  

  experience. 
  Such 
  behaviour 
  is, 
  I 
  conceive, 
  a 
  more 
  or 
  less 
  

   complex 
  organic 
  or 
  biological 
  response 
  to 
  a 
  more 
  or 
  less 
  

   complex 
  group 
  of 
  stimuli 
  of 
  external 
  and 
  internal 
  origin, 
  

   and 
  it 
  is, 
  as 
  such, 
  wholly 
  dependent 
  on 
  how 
  the 
  organism, 
  

   and 
  especially 
  the 
  nervous 
  system 
  and 
  brain 
  centres, 
  have 
  

   been 
  built 
  through 
  heredity 
  under 
  that 
  mode 
  of 
  racial 
  prep- 
  

   aration 
  which 
  we 
  call 
  biological 
  evolution 
  ' 
  (Instinct 
  and 
  

   Experience, 
  1912, 
  p. 
  5). 
  

  

  It 
  is 
  confusing 
  to 
  use 
  the 
  term 
  instinctive 
  so 
  loosely 
  that 
  

   it 
  becomes 
  almost 
  equivalent 
  to 
  hereditary 
  or 
  inborn, 
  as 
  in 
  

   phrases 
  like 
  instinctive 
  pugnacity 
  or 
  instinctive 
  gregarious- 
  

   ness, 
  for 
  the 
  usefulness 
  of 
  the 
  term 
  is 
  in 
  reference 
  to 
  specific 
  

   behaviour. 
  Yet 
  it 
  may 
  be 
  legitimate 
  and 
  useful 
  to 
  distin- 
  

   guish 
  between 
  general 
  instinctive 
  tendencies 
  and 
  specialised 
  

   instinctive 
  behaviour. 
  A 
  general 
  instinctive 
  tendency 
  is 
  the 
  

   expression 
  of 
  an 
  inborn 
  impulsion 
  which 
  has 
  not 
  much 
  par- 
  

   ticular 
  content, 
  such 
  as 
  is 
  shown 
  by 
  mammals 
  who 
  are 
  about 
  

   to 
  become 
  mothers 
  for 
  the 
  first 
  time, 
  or 
  by 
  an 
  isolated 
  hen- 
  

   bird 
  who 
  fumbles 
  at 
  nest-making, 
  or 
  in 
  the 
  so-called 
  i 
  sex- 
  

   instinct 
  '. 
  Thus 
  we 
  ourselves 
  have 
  many 
  instinctive 
  ten- 
  

   dencies, 
  but 
  few 
  instincts. 
  These 
  general 
  instinctive 
  ten- 
  

   dencies 
  are 
  to 
  be 
  distinguished 
  from 
  fundamental 
  appetites 
  

   such 
  as 
  hunger, 
  and 
  also 
  from 
  general 
  tropisms, 
  illustrated, 
  

   for 
  instance, 
  when 
  young 
  birds 
  gather 
  under 
  a 
  tea-cosy 
  as 
  

   under 
  a 
  mother 
  where 
  we 
  have 
  evidently 
  to 
  do 
  with 
  sim- 
  

   ilar 
  responses 
  to 
  similar 
  stimuli. 
  

  

  9. 
  Theories 
  of 
  Instinct. 
  

  

  It 
  is 
  too 
  soon 
  to 
  come 
  to 
  any 
  hard-and-fast 
  conclusion 
  

   in 
  regard 
  to 
  the 
  nature 
  of 
  instinctive 
  behaviour. 
  We 
  have 
  

   not 
  yet 
  got 
  the 
  facts 
  fully 
  before 
  us, 
  and 
  there 
  is 
  much 
  

   need 
  of 
  more 
  experimental 
  study. 
  It 
  is 
  almost 
  certain 
  that 
  

  

  