﻿Production 
  of 
  Double 
  Flowers 
  505 
  

  

  that 
  this 
  visible 
  leap 
  directly 
  corresponded 
  to 
  

   that 
  inner 
  change, 
  which 
  brought 
  about 
  the 
  com- 
  

   plete 
  inheritability 
  of 
  the 
  new 
  peculiarity. 
  It 
  

   is 
  very 
  interesting 
  to 
  observe 
  how 
  completely 
  

   my 
  experience 
  agrees 
  with 
  the 
  results 
  of 
  the 
  

   observations 
  of 
  breeders 
  at 
  large. 
  No 
  doubt 
  

   a 
  comparison 
  is 
  difficult, 
  and 
  the 
  circumstances 
  

   are 
  not 
  adequate 
  to 
  a 
  close 
  study. 
  

  

  Isolation 
  and 
  selection 
  have 
  been 
  applied 
  com- 
  

   monly 
  only 
  so 
  far 
  as 
  was 
  consistent 
  with 
  the 
  re- 
  

   quirements 
  of 
  practical 
  horticulture, 
  and 
  of 
  

   course 
  a 
  determination 
  of 
  the 
  hereditary 
  per- 
  

   centage 
  was 
  never 
  made. 
  The 
  disregard 
  of 
  this 
  

   feature 
  made 
  necessary 
  a 
  greater 
  length 
  of 
  time 
  

   and 
  a 
  larger 
  number 
  of 
  generations 
  to 
  bring 
  

   about 
  the 
  desired 
  changes. 
  Notwithstanding 
  

   this, 
  however, 
  it 
  has 
  been 
  seen 
  that 
  double 
  va- 
  

   rieties 
  are 
  produced 
  suddenly. 
  This 
  may 
  have 
  

   occurred 
  unexpectedly 
  or 
  after 
  a 
  few 
  years 
  ' 
  ef- 
  

   fort 
  toward 
  the 
  end 
  desired. 
  Whether 
  this 
  

   sudden 
  appearance 
  is 
  the 
  consequence 
  of 
  a 
  

   single 
  internal 
  differentiating 
  step, 
  or 
  of 
  the 
  

   rapid 
  succession 
  of 
  lesser 
  changes, 
  cannot 
  yet 
  

   be 
  made 
  out. 
  The 
  extreme 
  variability 
  of 
  dou- 
  

   ble 
  flowers 
  and 
  the 
  chance 
  of 
  their 
  appearance 
  

   with 
  only 
  slight 
  indications 
  of 
  the 
  previous 
  pet- 
  

   aloid 
  alterations 
  of 
  a 
  few 
  stamens 
  may 
  often 
  re- 
  

   sult 
  in 
  their 
  origin 
  being 
  overlooked, 
  while 
  

   subsequent 
  generations 
  may 
  come 
  in 
  for 
  full 
  no- 
  

  

  