﻿Inconstancy 
  of 
  Improved 
  Races 
  111 
  

  

  given 
  for 
  the 
  test 
  of 
  the 
  corn. 
  The 
  progression 
  

   and 
  regression 
  were 
  found 
  to 
  be 
  proportionate 
  

   to 
  the 
  amount 
  of 
  the 
  deviation. 
  The 
  progres- 
  

   sion 
  of 
  the 
  average 
  was 
  one-third, 
  and 
  the 
  re- 
  

   gression 
  in 
  consequence 
  two-thirds 
  of 
  the 
  total 
  

   deviation. 
  The 
  amelioration 
  is 
  thus 
  seen 
  to 
  be 
  

   nearly, 
  though 
  not 
  exactly, 
  the 
  same 
  as 
  in 
  the 
  

   previous 
  case. 
  

  

  From 
  the 
  evidence 
  of 
  the 
  other 
  correspond- 
  

   ing 
  experiments, 
  and 
  from 
  various 
  statistical 
  

   inquiries 
  it 
  seems 
  that 
  the 
  value 
  of 
  the 
  pro- 
  

   gression 
  is 
  nearly 
  the 
  same 
  in 
  most 
  cases, 
  irre- 
  

   spective 
  of 
  the 
  species 
  used 
  and 
  the 
  quality 
  con- 
  

   sidered. 
  It 
  may 
  be 
  said 
  to 
  be 
  from 
  one-third 
  to 
  

   one-half 
  of 
  the 
  parental 
  deviation, 
  and 
  in 
  this 
  

   form 
  the 
  statement 
  is 
  obviously 
  of 
  wide 
  and 
  

   easy 
  applicability. 
  

  

  Our 
  figures 
  also 
  demonstrate 
  the 
  great 
  pre- 
  

   eminence 
  of 
  vegetative 
  varieties 
  above 
  the 
  im- 
  

   proved 
  strains 
  multiplied 
  by 
  seeds. 
  They 
  have 
  

   a 
  definite 
  relation. 
  Asexually 
  multiplied 
  

   strains 
  may 
  be 
  said 
  to 
  be 
  generally 
  two 
  times 
  

   or 
  even 
  three 
  times 
  superior 
  to 
  the 
  com- 
  

   mon 
  offspring. 
  This 
  is 
  a 
  difference 
  of 
  great 
  

   practical 
  importance, 
  and 
  should 
  never 
  be 
  lost 
  

   sight 
  of 
  in 
  theoretical 
  considerations 
  of 
  the 
  pro- 
  

   ductive 
  capacity 
  of 
  selection. 
  Multiplication 
  by 
  

   seed 
  however, 
  has 
  one 
  great 
  advantage 
  over 
  

   the 
  asexual 
  method; 
  it 
  may 
  be 
  repeated. 
  The 
  

  

  