﻿304 
  Retrograde 
  Varieties 
  

  

  wards 
  in 
  the 
  red 
  campion, 
  but 
  lack 
  this 
  capacity 
  

   in 
  the 
  evening-campion, 
  diverging 
  only 
  until 
  an 
  

   upright 
  position 
  is 
  reached. 
  The 
  combination 
  

   of 
  hairs, 
  colors 
  and 
  teeth 
  gives 
  eight 
  groups, 
  

   and 
  the 
  counting 
  of 
  their 
  respective 
  numbers 
  of 
  

   individuals 
  gave 
  the 
  following 
  result 
  : 
  

  

  The 
  agreement 
  is 
  as 
  comprehensive 
  as 
  might 
  

   be 
  expected 
  from 
  an 
  experiment 
  with 
  about 
  200 
  

   plants, 
  and 
  there 
  can 
  be 
  no 
  doubt 
  that 
  a 
  repeti- 
  

   tion 
  on 
  a 
  larger 
  scale 
  would 
  give 
  still 
  closer 
  

   agreement. 
  

  

  In 
  the 
  same 
  way 
  we 
  might 
  proceed 
  to 
  crosses 
  

   with 
  four 
  or 
  more 
  differentiating 
  characters. 
  

   But 
  each 
  new 
  character 
  will 
  double 
  the 
  number 
  

   of 
  the 
  groups. 
  Four 
  characters 
  will 
  combine 
  

   into 
  16 
  groups, 
  five 
  into 
  32, 
  six 
  into 
  64, 
  seven 
  

   into 
  128, 
  etc. 
  Hence 
  it 
  is 
  easily 
  seen 
  that 
  the 
  

   size 
  of 
  the 
  experiments 
  must 
  be 
  made 
  larger 
  

   and 
  larger 
  in 
  the 
  same 
  ratio, 
  if 
  we 
  intend 
  to 
  

   expect 
  numbers 
  equally 
  trustworthy. 
  For 
  

  

  