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  Fluctuations 
  

  

  The 
  pollen 
  falls 
  from 
  the 
  male 
  spikes 
  on 
  the 
  

   ears 
  of 
  the 
  same 
  plant, 
  but 
  also 
  is 
  easily 
  blown 
  

   on 
  surrounding 
  spikes. 
  In 
  order 
  to 
  get 
  the 
  

   required 
  amount 
  of 
  seed 
  it 
  is 
  necessary 
  in 
  our 
  

   climate 
  to 
  encroach 
  as 
  little 
  as 
  possible 
  upon 
  

   free 
  pollination, 
  aiding 
  the 
  self-pollination, 
  

   but 
  taking 
  no 
  precautions 
  against 
  intercross- 
  

   ing. 
  It 
  is 
  assumed 
  that 
  the 
  choice 
  of 
  the 
  best 
  

   ears 
  indicates 
  the 
  plants 
  which 
  have 
  had 
  the 
  

   best 
  pollen-parents 
  as 
  well 
  as 
  the 
  best 
  pistil- 
  

   parents, 
  and 
  that 
  selection 
  here, 
  as 
  in 
  other 
  

   cases, 
  corrects 
  the 
  faults 
  of 
  free 
  intercrossing. 
  

   But 
  it 
  is 
  granted 
  that 
  this 
  correction 
  is 
  only 
  a 
  

   slow 
  one, 
  and 
  accounts 
  in 
  a 
  great 
  degree 
  for 
  the 
  

   slowness 
  of 
  the 
  progression. 
  Under 
  better 
  cli- 
  

   matic 
  conditions 
  and 
  with 
  a 
  more 
  entire 
  isola- 
  

   tion 
  of 
  the 
  individuals, 
  it 
  seems 
  very 
  probable 
  

   that 
  the 
  same 
  result 
  could 
  have 
  been 
  reached 
  

   in 
  fewer 
  generations. 
  

  

  However 
  this 
  may 
  be, 
  the 
  fact 
  is 
  that 
  by 
  re- 
  

   peated 
  selection 
  the 
  strain 
  can 
  be 
  ameliorated 
  

   to 
  a 
  greater 
  extent 
  than 
  by 
  a 
  single 
  choice. 
  This 
  

   result 
  completely 
  agrees 
  with 
  the 
  general 
  expe- 
  

   rience 
  of 
  breeders 
  and 
  the 
  example 
  given 
  

   is 
  only 
  an 
  instance 
  of 
  a 
  universal 
  rule. 
  It 
  has 
  

   the 
  advantage 
  of 
  being 
  capable 
  of 
  being 
  re- 
  

   corded 
  in 
  a 
  numerical 
  way, 
  and 
  of 
  allowing 
  a 
  

   detailed 
  and 
  definite 
  description 
  of 
  all 
  the 
  suc- 
  

   ceeding 
  generations. 
  The 
  entire 
  harvest 
  of 
  all 
  

  

  