﻿478 
  Mutations 
  

  

  only 
  vicinists, 
  caused 
  by 
  stray 
  pollen 
  grains 
  

   from 
  another 
  culture, 
  cannot 
  of 
  course 
  be 
  de- 
  

   cided 
  with 
  sufficient 
  certitude. 
  

  

  Here 
  I 
  might 
  refer 
  to 
  the 
  observations 
  con- 
  

   cerning 
  the 
  invisible 
  dimorphous 
  state 
  of 
  the 
  

   flowers 
  of 
  the 
  normal 
  toad-flax. 
  Individuals 
  of 
  

   the 
  same 
  type, 
  when 
  fertilized 
  with 
  each 
  other, 
  

   are 
  nearly, 
  but 
  not 
  absolutely, 
  sterile. 
  The 
  

   yield 
  of 
  seeds 
  of 
  my 
  peloric 
  plants 
  agrees 
  fairly 
  

   well 
  with 
  the 
  harvest 
  which 
  I 
  have 
  obtained 
  

   from 
  some 
  of 
  the 
  nearly 
  sterile 
  pairs 
  of 
  indi- 
  

   viduals 
  in 
  my 
  former 
  trial. 
  Hence 
  the 
  sugges- 
  

   tion 
  is 
  forced 
  upon 
  us 
  that 
  perhaps, 
  owing 
  to 
  

   some 
  unknown 
  cause, 
  all 
  the 
  peloric 
  individuals 
  

   of 
  my 
  experiment 
  belonged 
  to 
  one 
  and 
  the 
  same 
  

   type, 
  and 
  were 
  sterile 
  for 
  this 
  reason 
  only. 
  If 
  

   this 
  is 
  true, 
  then 
  it 
  is 
  to 
  be 
  presumed 
  that 
  all 
  

   previous 
  investigators 
  have 
  met 
  the 
  same 
  con- 
  

   dition, 
  each 
  having 
  at 
  hand 
  only 
  one 
  of 
  the 
  two 
  

   required 
  types. 
  And 
  this 
  discussion 
  has 
  

   the 
  further 
  advantage 
  of 
  showing 
  the 
  way, 
  

   in 
  which 
  perhaps 
  a 
  full 
  and 
  constant 
  race 
  of 
  

   peloric 
  toad-flaxes 
  may 
  be 
  obtained. 
  Two 
  indi- 
  

   viduals 
  of 
  different 
  type 
  are 
  required 
  to 
  start 
  

   from. 
  They 
  seem 
  as 
  yet 
  never 
  to 
  have 
  arisen 
  

   from 
  one 
  group 
  of 
  mutations. 
  But 
  if 
  it 
  were 
  

   possible 
  to 
  combine 
  the 
  products 
  of 
  two 
  muta- 
  

   tions 
  obtained 
  in 
  different 
  countries 
  and 
  under 
  

   different 
  conditions, 
  there 
  would 
  be 
  a 
  chance 
  

  

  