﻿Production 
  of 
  Double 
  Flowers 
  495 
  

  

  individuals 
  with 
  the 
  lesser 
  degrees 
  of 
  deviation. 
  

   Now 
  the 
  marigold 
  averages 
  13, 
  and 
  the 
  

   grandiflprum 
  21 
  rays. 
  The 
  wild 
  species 
  is 
  pure 
  

   in 
  this 
  respect, 
  but 
  the 
  garden-variety 
  is 
  not. 
  

   The 
  seeds 
  which 
  are 
  offered 
  for 
  sale 
  usually 
  

   contain 
  a 
  mixture 
  of 
  both 
  forms 
  and 
  their 
  

   hybrids. 
  So 
  I 
  had 
  to 
  isolate 
  the 
  pure 
  types 
  

   from 
  this 
  mixture 
  and 
  to 
  ascertain 
  their 
  con- 
  

   stancy 
  and 
  mutual 
  independency. 
  To 
  this 
  end 
  

   I 
  isolated 
  from 
  the 
  mixture 
  first 
  the 
  13-rayed, 
  

   and 
  afterwards 
  the 
  21-rayed 
  types. 
  As 
  the 
  

   marigolds 
  are 
  not 
  sufficiently 
  self-fertile, 
  and 
  

   are 
  not 
  easily 
  pollinated 
  artificially, 
  it 
  seemed 
  

   impossible 
  to 
  carry 
  on 
  these 
  two 
  experiments 
  at 
  

   the 
  same 
  time 
  and 
  in 
  the 
  same 
  garden. 
  I 
  de- 
  

   voted 
  the 
  first 
  three 
  years 
  to 
  the 
  lower 
  form, 
  

   isolated 
  some 
  individuals 
  with 
  12-13 
  rays 
  out 
  of 
  

   the 
  mixture 
  of 
  1892 
  and 
  counted 
  the 
  ray-florets 
  

   on 
  the 
  terminal 
  head 
  of 
  every 
  plant 
  of 
  the 
  en- 
  

   suing 
  generation 
  next 
  year. 
  I 
  cultivated 
  and 
  

   counted 
  in 
  this 
  way 
  above 
  150 
  individuals 
  and 
  

   found 
  an 
  average 
  of 
  exactly 
  13 
  with 
  compara- 
  

   tively 
  few 
  individuals 
  displaying 
  14 
  or 
  only 
  12 
  

   rays, 
  and 
  with 
  the 
  remainder 
  of 
  the 
  plants 
  

   grouped 
  symmetrically 
  around 
  this 
  average. 
  I 
  

   continued 
  the 
  experiment 
  for 
  still 
  another 
  year 
  

   and 
  found 
  the 
  same 
  group 
  of 
  figures. 
  I 
  was 
  

   then 
  satisfied 
  as 
  to 
  the 
  purity 
  of 
  the 
  isolated 
  

   strain. 
  Next 
  year 
  I 
  sowed 
  a 
  new 
  mixture 
  in 
  

  

  