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  Fluctuations 
  

  

  In 
  other 
  words, 
  there 
  is 
  a 
  progression 
  and 
  a 
  re- 
  

   gression. 
  A 
  progression 
  in 
  relation 
  to 
  the 
  whole 
  

   race, 
  and 
  a 
  regression 
  in 
  comparison 
  with 
  the 
  

   parent. 
  The 
  significance 
  of 
  this 
  becomes 
  clear 
  

   at 
  once, 
  if 
  we 
  recall 
  the 
  constancy 
  of 
  the 
  variety 
  

   which 
  could 
  be 
  obtained 
  from 
  the 
  selected 
  ex- 
  

   treme 
  in 
  the 
  case 
  of 
  vegetative 
  multiplication. 
  

   The 
  progression 
  is 
  what 
  the 
  breeder 
  wants, 
  the 
  

   regression 
  what 
  he 
  detests. 
  Regression 
  is 
  the 
  

   permanency 
  of 
  part 
  of 
  the 
  mediocrity 
  which 
  

   the 
  selection 
  was 
  invoked 
  to 
  overcome. 
  Mani- 
  

   festly 
  it 
  is 
  of 
  the 
  highest 
  interest 
  that 
  the 
  pro- 
  

   gression 
  should 
  be 
  as 
  large, 
  and 
  the 
  regression 
  

   as 
  small 
  as 
  possible. 
  In 
  order 
  to 
  attain 
  this 
  

   goal 
  the 
  first 
  question 
  is 
  to 
  know 
  the 
  exact 
  meas- 
  

   ure 
  of 
  progression 
  and 
  regression 
  as 
  they 
  are 
  

   exhibiting 
  themselves 
  in 
  the 
  given 
  cases, 
  and 
  

   the 
  second 
  is 
  to 
  inquire 
  into 
  the 
  influences, 
  on 
  

   which 
  this 
  proportion 
  may 
  be 
  incumbent, 
  

  

  At 
  present 
  our 
  notions 
  concerning 
  the 
  first 
  

   point 
  are 
  still 
  very 
  limited 
  and 
  those 
  concern- 
  

   ing 
  the 
  second 
  extremely 
  vague. 
  Statistical 
  in- 
  

   quiries 
  have 
  led 
  to 
  some 
  definite 
  ideas 
  about 
  the 
  

   importance 
  of 
  regression, 
  and 
  these 
  furnish 
  a 
  

   basis 
  for 
  experimental 
  researches 
  concerning 
  

   the 
  causes 
  of 
  the 
  phenomenon. 
  Very 
  ad- 
  

   vantageous 
  material 
  for 
  the 
  study 
  of 
  pro- 
  

   gression 
  and 
  regression 
  in 
  the 
  realm 
  of 
  

   fluctuating 
  variability 
  is 
  afforded 
  by 
  the 
  

  

  