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  ANIMAL 
  BEHAVIOUR 
  

  

  and 
  religion 
  this 
  compromise 
  between 
  determinist 
  and 
  free- 
  

   will 
  interpretations 
  which 
  biology 
  suggests. 
  

  

  SUMMARY. 
  

  

  Only 
  in 
  the 
  realm 
  of 
  organisms 
  is 
  there 
  true 
  behaviour 
  in 
  which 
  

   the 
  creature 
  is 
  an 
  agent 
  and 
  exhibits 
  a 
  correlated 
  or 
  concatenated 
  

   series 
  of 
  acts, 
  effective 
  towards 
  some 
  definite 
  result 
  favourable 
  to 
  

   the 
  harmony 
  of 
  vital 
  processes 
  and 
  the 
  continuance 
  of 
  the 
  race. 
  

  

  Among 
  unicellular 
  or 
  non-cellular 
  organisms 
  there 
  is 
  often 
  a 
  

   restless 
  locomotor 
  activity, 
  hardly 
  on 
  the 
  level 
  of 
  behaviour, 
  which 
  

   is 
  sustained 
  by 
  the 
  everyday 
  internal 
  functions 
  and 
  is 
  not 
  very 
  

   clearly 
  separable 
  from 
  them. 
  There 
  are 
  also 
  definite 
  organic 
  re- 
  

   actions 
  to 
  all 
  sorts 
  of 
  stimuli 
  except 
  sound 
  waves, 
  corresponding 
  

   in 
  a 
  far-off 
  way 
  to 
  reflex 
  actions 
  in 
  higher 
  animals. 
  In 
  difficult 
  

   situations 
  there 
  may 
  be 
  a 
  trial-and-error 
  procedure, 
  a 
  selection 
  of 
  

   the 
  fittest 
  answer 
  and 
  a 
  short-lived 
  modification 
  of 
  behaviour 
  in 
  

   relation 
  to 
  experience. 
  As 
  Professor 
  Jennings 
  especially 
  has 
  

   shown, 
  there 
  is 
  among 
  the 
  simplest 
  animals 
  the 
  counterpart 
  of 
  

   intelligent 
  behaviour. 
  

  

  Of 
  great 
  interest 
  is 
  the 
  shell-building 
  of 
  some 
  of 
  the 
  arenaceous 
  

   Foraminifera, 
  where 
  particular 
  materials, 
  such 
  as 
  sponge-spicules, 
  

   are 
  selected 
  from 
  amid 
  an 
  embarrassment 
  of 
  alternatives, 
  and 
  

   where 
  the 
  selected 
  material 
  is 
  utilised 
  in 
  a 
  particularly 
  effective 
  way. 
  

  

  Reflex 
  actions 
  are 
  usually 
  movements 
  of 
  parts, 
  uniform 
  reactions 
  

   to 
  a 
  particular 
  kind 
  of 
  external 
  or 
  internal 
  stimulus, 
  exhibited 
  ap- 
  

   proximately 
  to 
  the 
  same 
  extent 
  by 
  all 
  animals 
  of 
  the 
  same 
  kind, 
  

   and 
  depending 
  on 
  inborn 
  structural 
  linkages 
  of 
  nerve-cells 
  and 
  

   muscle-cells. 
  But 
  reflexes, 
  though 
  not 
  alterable 
  by 
  experience, 
  are 
  

   sometimes 
  controlled 
  by 
  what 
  looks 
  like 
  some 
  appreciation 
  of 
  cir- 
  

   cumstances. 
  ' 
  Chain-reflexes 
  ' 
  are 
  often 
  broken. 
  

  

  Another 
  simple 
  form 
  of 
  animal 
  activity 
  is 
  seen 
  in 
  tropisms 
  

   more 
  or 
  less 
  obligatory 
  movements, 
  like 
  the 
  moth's 
  to 
  the 
  candle, 
  

   which 
  automatically 
  tend 
  to 
  secure 
  physiological 
  equilibrium 
  in 
  

   reference 
  to 
  particular 
  stimuli. 
  But 
  the 
  tropistic 
  coercion 
  is 
  some- 
  

   times 
  successfully 
  thwarted 
  by 
  individual 
  experiment 
  on 
  the 
  part 
  

   of 
  the 
  organism. 
  

  

  One 
  of 
  the 
  most 
  important 
  results 
  of 
  recent 
  studies 
  is 
  the 
  proof 
  

   that 
  many 
  brainless 
  and 
  even 
  ganglionless 
  animals, 
  such 
  as 
  star- 
  

   fishes 
  and 
  sea-urchins, 
  exhibit 
  a 
  counterpart 
  of 
  the 
  intelligent 
  be- 
  

  

  