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  ADAPTIVENESS 
  AND 
  PURPOSIVENESS 
  

  

  narrowest 
  hinge 
  in 
  my 
  hand 
  puts 
  to 
  scorn 
  all 
  machinery"; 
  

   the 
  hand 
  as 
  a 
  whole 
  is 
  the 
  subject 
  of 
  a 
  Bridgewater 
  Treatise. 
  

   The 
  Vertebrate 
  eye 
  is 
  extraordinarily 
  well 
  adapted, 
  in 
  spite 
  

   of 
  the 
  instrumental 
  imperfections 
  which 
  Helmholtz 
  discov- 
  

   ered. 
  The 
  functional 
  correlations 
  of 
  internal 
  organs 
  such 
  

   as 
  heart 
  and 
  lungs 
  are 
  as 
  effective 
  as 
  they 
  are 
  delicate. 
  The 
  

   flat-fish 
  is 
  so 
  adaptable 
  in 
  its 
  coloration 
  to 
  the 
  pattern 
  of 
  

   the 
  sea-floor 
  on 
  which 
  it 
  rests 
  that 
  it 
  has 
  practically 
  a 
  Gyges 
  

   ring, 
  making 
  itself 
  invisible, 
  sometimes 
  almost 
  instantane- 
  

   ously. 
  Flowers 
  and 
  their 
  welcome 
  insect-visitors 
  are 
  suited 
  

   to 
  one 
  another 
  as 
  glove 
  to 
  hand. 
  The 
  realm 
  of 
  organisms 
  

   abounds 
  in 
  adaptations, 
  some 
  extraordinarily 
  perfect, 
  some 
  

   in 
  process 
  of 
  becoming 
  perfect. 
  

  

  First 
  there 
  are 
  the 
  structural 
  adaptations 
  of 
  the 
  organism 
  

   some 
  with 
  internal 
  and 
  some 
  with 
  external 
  reference, 
  

   some 
  static, 
  some 
  dynamic. 
  The 
  internal 
  structure 
  of 
  a 
  long 
  

   bone 
  or 
  of 
  the 
  stem 
  of 
  a 
  plant 
  is 
  suited 
  in 
  detail 
  to 
  stand 
  

   the 
  strains 
  and 
  stresses 
  to 
  which 
  it 
  is 
  exposed. 
  The 
  same 
  

   quality 
  of 
  architectural 
  stability 
  may 
  be 
  seen 
  everywhere 
  

   from 
  the 
  scaffolding 
  of 
  a 
  siliceous 
  sponge 
  like 
  Venus's 
  Flower 
  

   Basket 
  to 
  the 
  spine 
  of 
  a 
  sea-urchin, 
  from 
  the 
  spirally 
  twisted 
  

   encasement 
  of 
  an 
  arenaceous 
  Foraminifer 
  to 
  the 
  prismatic 
  

   structure 
  of 
  the 
  enamel 
  of 
  our 
  teeth. 
  

  

  Less 
  static 
  are 
  the 
  adaptations 
  of 
  parts 
  that 
  move 
  and 
  

   work. 
  The 
  adaptations 
  of 
  a 
  bird's 
  skeleton 
  for 
  flight 
  and 
  

   for 
  bipedal 
  progression 
  are 
  many 
  and 
  thorough. 
  The 
  heart 
  

   is 
  a 
  masterpiece 
  of 
  fitness, 
  and 
  in 
  many 
  cases, 
  as 
  in 
  the 
  

   antelope 
  on 
  the 
  plains 
  or 
  in 
  the 
  ptarmigan 
  on 
  the 
  high 
  moun- 
  

   tains, 
  there 
  are 
  interesting 
  special 
  adaptations 
  of 
  the 
  heart 
  

   to 
  stand 
  special 
  strain. 
  The 
  delicacy 
  and 
  complexity 
  of 
  the 
  

   mouth-parts 
  of 
  such 
  insects 
  as 
  mosquitoes 
  may 
  well 
  evoke 
  the 
  

   artificer's 
  admiration. 
  

  

  