﻿Inconstancy 
  of 
  Improved 
  Races 
  787 
  

  

  continued 
  the 
  culture 
  during 
  several 
  genera- 
  

   tions, 
  choosing 
  ears 
  with 
  less 
  than 
  the 
  average 
  

   number 
  of 
  rows. 
  The 
  excellence 
  of 
  the 
  

   race 
  at 
  once 
  disappeared, 
  and 
  the 
  ordinary 
  

   average 
  of 
  the 
  variety 
  from 
  which 
  I 
  had 
  started 
  

   seven 
  years 
  before, 
  returned 
  within 
  two 
  or 
  three 
  

   seasons. 
  This 
  shows 
  that 
  the 
  attained 
  improve- 
  

   ment 
  is 
  neither 
  fixed 
  nor 
  assured 
  and 
  is 
  depend- 
  

   ent 
  on 
  continued 
  selection. 
  This 
  result 
  only 
  

   confirms 
  the 
  universal 
  experience 
  of 
  breeders, 
  

   which 
  teaches 
  the 
  general 
  dependency 
  of 
  im- 
  

   proved 
  races 
  on 
  continued 
  selection. 
  Here 
  a 
  

   striking 
  contrast 
  with 
  elementary 
  species 
  or 
  

   true 
  varieties 
  is 
  obvious. 
  The 
  strains 
  which 
  na- 
  

   ture 
  affords 
  are 
  true 
  to 
  their 
  type; 
  their 
  aver- 
  

   age 
  condition 
  remains 
  the 
  same 
  during 
  all 
  the 
  

   succeeding 
  generations, 
  and 
  even 
  if 
  it 
  should 
  

   be 
  slightly 
  altered 
  by 
  changes 
  in 
  the 
  external 
  

   conditions, 
  it 
  returns 
  to 
  the 
  type, 
  as 
  soon 
  as 
  

   these 
  changes 
  come 
  to 
  an 
  end. 
  It 
  is 
  a 
  real 
  aver- 
  

   age, 
  being 
  the 
  sum 
  of 
  the 
  contribution 
  of 
  all 
  

   the 
  members 
  of 
  the 
  strain. 
  Improved 
  races 
  

   have 
  only 
  an 
  apparent 
  average, 
  which 
  is 
  in 
  fact 
  

   biased 
  by 
  the 
  exclusion 
  of 
  whole 
  groups 
  of 
  in- 
  

   dividuals. 
  If 
  left 
  to 
  themselves, 
  their 
  appear- 
  

   ance 
  changes, 
  and 
  the 
  real 
  average 
  soon 
  re- 
  

   turns. 
  This 
  is 
  the 
  common 
  experience 
  of 
  breed- 
  

   ers. 
  

  

  A 
  third 
  point 
  is 
  to 
  be 
  discussed 
  in 
  con- 
  

  

  