﻿Inconstancy 
  of 
  Improved 
  Races 
  797 
  

  

  bad 
  years 
  giving 
  10$, 
  good 
  years 
  from 
  12$ 
  to 
  

   14$ 
  in 
  the 
  average. 
  Extreme 
  instances 
  exceeded 
  

   17$. 
  From 
  that 
  time 
  the 
  practice 
  of 
  the 
  polar- 
  

   ization 
  of 
  the 
  juice 
  for 
  the 
  estimate 
  of 
  the 
  sugar 
  

   has 
  rapidly 
  spread 
  throughout 
  Europe, 
  and 
  a 
  

   definite 
  increase 
  of 
  the 
  average 
  value 
  soon 
  re- 
  

   sulted. 
  This 
  however, 
  often 
  does 
  not 
  exceed 
  

   14$, 
  and 
  beets 
  selected 
  in 
  the 
  field 
  for 
  the 
  pur- 
  

   pose 
  of 
  polarization 
  come 
  up 
  to 
  an 
  average 
  of 
  

   15 
  to 
  16$, 
  varying 
  downward 
  to 
  less 
  than 
  10$ 
  

   and 
  upward 
  to 
  20 
  and 
  21$. 
  In 
  the 
  main 
  the 
  fig- 
  

   ures 
  are 
  the 
  same 
  as 
  those 
  of 
  Vilmorin, 
  the 
  

   range 
  of 
  variability 
  has 
  not 
  been 
  reduced, 
  and 
  

   higher 
  extremes 
  are 
  not 
  reached. 
  An 
  average 
  

   increase 
  of 
  1$ 
  is 
  of 
  great 
  practical 
  importance, 
  

   and 
  nothing 
  can 
  excel 
  the 
  industry 
  and 
  care 
  dis- 
  

   played 
  in 
  the 
  improvement 
  of 
  the 
  beet-races. 
  

   Notwithstanding 
  this 
  a 
  lasting 
  influence 
  has 
  not 
  

   been 
  exercised; 
  the 
  methods 
  of 
  selection 
  have 
  

   been 
  improved, 
  and 
  the 
  number 
  of 
  polarized 
  

   beets 
  has 
  been 
  brought 
  up 
  to 
  some 
  hundreds 
  of 
  

   thousands 
  in 
  single 
  factories, 
  but 
  the 
  improve- 
  

   ment 
  is 
  still 
  as 
  dependent 
  upon 
  continuous 
  selec- 
  

   tion 
  as 
  it 
  was 
  half 
  a 
  century 
  ago. 
  

  

  The 
  process 
  is 
  practically 
  very 
  successful, 
  but 
  

   the 
  support 
  afforded 
  by 
  it 
  to 
  the 
  selection- 
  

   theory 
  vanishes 
  on 
  critical 
  examination. 
  

  

  