﻿Artificial 
  and 
  Natural 
  Selection 
  807 
  

  

  size 
  and 
  color 
  are 
  usually 
  easy 
  and 
  rapid 
  in 
  the 
  

   beginning*, 
  but 
  an 
  impassable 
  limit 
  is 
  soon 
  

   reached. 
  Numerous 
  other 
  instances 
  could 
  be 
  

   given. 
  

  

  Contrasted 
  with 
  these 
  simple 
  cases 
  is 
  the 
  

   method 
  of 
  selecting 
  sugar-beets. 
  More 
  than 
  

   once 
  I 
  have 
  alluded 
  to 
  this 
  splendid 
  exam- 
  

   ple 
  of 
  the 
  influence 
  of 
  man 
  upon 
  domestic 
  races, 
  

   and 
  tried 
  to 
  point 
  out 
  how 
  little 
  support 
  it 
  af- 
  

   fords 
  to 
  the 
  current 
  scientific 
  opinion 
  concern- 
  

   ing 
  the 
  power 
  of 
  natural 
  selection. 
  For 
  this 
  

   reason 
  it 
  is 
  interesting 
  to 
  see 
  how 
  a 
  gradual 
  

   development 
  of 
  the 
  methods 
  of 
  selection 
  has 
  

   been, 
  from 
  the 
  very 
  outset, 
  one 
  of 
  the 
  chief 
  aims 
  

   of 
  the 
  breeders. 
  None 
  of 
  them 
  doubts 
  that 
  an 
  

   improvement 
  of 
  the 
  method 
  alone 
  is 
  adequate 
  to 
  

   obtain 
  results. 
  This 
  result, 
  in 
  the 
  main, 
  is 
  the 
  

   securing 
  of 
  a 
  few 
  per-cent 
  more 
  of 
  sugar, 
  a 
  

   change 
  hardly 
  comparable 
  with 
  that 
  progress 
  

   in 
  evolution, 
  which 
  our 
  theories 
  are 
  destined 
  to 
  

   explain. 
  

  

  Vilmorin's 
  original 
  method 
  was 
  a 
  very 
  simple 
  

   one. 
  Polarization 
  was 
  still 
  undiscovered 
  in 
  his 
  

   time. 
  He 
  determined 
  the 
  specific 
  weight 
  of 
  -his 
  

   beets, 
  either 
  by 
  weighing 
  them 
  as 
  a 
  whole, 
  or 
  by 
  

   using 
  a 
  piece 
  cut 
  from 
  the 
  base 
  of 
  the 
  roots 
  and 
  

   deprived 
  of 
  its 
  bark, 
  in 
  order 
  to 
  test 
  only 
  the 
  

   sugar-tissues. 
  The 
  pieces 
  were 
  floated 
  in 
  solu- 
  

   tions 
  of 
  salt, 
  which 
  were 
  diluted 
  until 
  the 
  pieces 
  

  

  