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  Fluctuations 
  

  

  selection 
  of 
  species 
  complies 
  as 
  closely 
  as 
  possi- 
  

   ble 
  with 
  existing 
  terminology, 
  and 
  does 
  not 
  

   seem 
  liable 
  to 
  any 
  misunderstanding. 
  

  

  It 
  is 
  a 
  selection 
  between 
  species. 
  Opposed 
  to 
  

   it 
  is 
  the 
  selection 
  ivithin 
  the 
  species. 
  Manifest- 
  

   ly 
  the 
  first 
  should 
  precede 
  the 
  second, 
  and 
  if 
  this 
  

   sequence 
  is 
  not 
  conscientiously 
  followed 
  it 
  will 
  

   result 
  in 
  confusion. 
  This 
  is 
  evident 
  when 
  it 
  

   is 
  considered 
  that 
  fluctuations 
  can 
  only 
  appear 
  

   with 
  their 
  pure 
  and 
  normal 
  type 
  in 
  pure 
  strains, 
  

   and 
  that 
  each 
  admixture 
  of 
  other 
  units 
  is 
  liable 
  

   to 
  be 
  shown 
  by 
  the 
  form 
  of 
  the 
  curves. 
  More- 
  

   over, 
  selection 
  chooses 
  single 
  individuals, 
  and 
  a 
  

   single 
  plant, 
  if 
  it 
  is 
  not 
  a 
  hybrid, 
  can 
  scarcely 
  

   pertain 
  to 
  two 
  different 
  species. 
  The 
  first 
  

   choice 
  therefore 
  is 
  apt 
  to 
  make 
  the 
  strain 
  pure. 
  

  

  In 
  contrasting 
  selection 
  between 
  species 
  with 
  

   that 
  within 
  the 
  species, 
  of 
  course 
  elementary 
  

   species 
  are 
  meant, 
  including 
  varieties. 
  The 
  

   terms 
  would 
  be 
  of 
  no 
  consequence 
  if 
  only 
  right- 
  

   ly 
  understood. 
  For 
  the 
  sake 
  of 
  clearness 
  we 
  

   might 
  designate 
  the 
  last 
  named 
  process 
  with 
  

   the 
  term 
  of 
  intra-specific 
  selection, 
  and 
  it 
  is 
  

   obvious 
  that 
  this 
  term 
  is 
  applicable 
  both 
  to 
  

   natural 
  and 
  to 
  artificial 
  selection. 
  

  

  Having 
  previously 
  dealt 
  with 
  species-selec- 
  

   tion 
  at 
  sufficient 
  length, 
  we 
  may 
  now 
  confine 
  our- 
  

   selves 
  to 
  the 
  consideration 
  of 
  the 
  intra-specific 
  

  

  