﻿Inconstancy 
  of 
  Improved 
  Races 
  789 
  

  

  rows. 
  Choosing 
  always 
  the 
  principal 
  ear, 
  

   the 
  figures 
  may 
  be 
  taken 
  to 
  indicate 
  the 
  de- 
  

   gree 
  of 
  personal 
  deviation 
  from 
  the 
  average 
  of 
  

   the 
  race. 
  But 
  whenever 
  we 
  make 
  a 
  mistake, 
  and 
  

   perchance 
  sow 
  from 
  an 
  ear, 
  the 
  deviation 
  of 
  

   which 
  was 
  largely 
  due 
  to 
  partial 
  variation, 
  the 
  

   regression 
  should 
  be 
  expected 
  to 
  become 
  con- 
  

   siderably 
  larger. 
  Hence 
  it 
  must 
  be 
  conceded 
  

   that 
  exact 
  calculations 
  of 
  the 
  phenomena 
  of 
  in- 
  

   heritance 
  are 
  subject 
  to 
  much 
  uncertainty, 
  

   resulting 
  from 
  our 
  very 
  imperfect 
  knowledge 
  

   concerning 
  the 
  real 
  proportion 
  of 
  the 
  contribut- 
  

   ing 
  factors, 
  and 
  the 
  difficulty 
  of 
  ascertaining 
  

   their 
  influence 
  in 
  any 
  given 
  case. 
  Here 
  also 
  we 
  

   encounter 
  more 
  doubts 
  than 
  real 
  facts, 
  and 
  much 
  

   remains 
  to 
  be 
  done 
  before 
  exact 
  calculations 
  

   may 
  become 
  of 
  real 
  scientific 
  value. 
  

  

  Returning 
  to 
  the 
  question 
  of 
  the 
  effects 
  of 
  se- 
  

   lection 
  in 
  the 
  long 
  run, 
  two 
  essentially 
  differ- 
  

   ent 
  cases 
  are 
  to 
  be 
  considered. 
  Extremes 
  may 
  

   be 
  selected 
  from 
  among 
  the 
  variants 
  of 
  ordinary 
  

   fluctuating 
  variability, 
  or 
  from 
  ever-sporting 
  

   varieties. 
  These 
  last 
  we 
  have 
  shown 
  to 
  be 
  

   double 
  races. 
  Their 
  peculiar 
  and 
  wide 
  range 
  of 
  

   variability 
  is 
  due 
  to 
  the 
  substitution 
  of 
  two 
  

   characters, 
  which 
  exclude 
  one 
  another, 
  or 
  if 
  

   combined, 
  are 
  diminished 
  in 
  various 
  degrees. 
  

   Striped 
  flowers 
  and 
  stocks, 
  "five-leaved" 
  clover, 
  

   pistilloid 
  opium-poppies 
  and 
  numerous 
  other 
  

  

  