﻿Polycephalic 
  Poppies 
  385 
  

  

  moment 
  no 
  further 
  change 
  of 
  external 
  condi- 
  

   tions 
  is 
  able 
  to 
  produce 
  a 
  corresponding 
  change 
  

   in 
  the 
  degree 
  of 
  the 
  anomaly. 
  The 
  indi- 
  

   vidual 
  strength 
  of 
  the 
  whole 
  plant 
  may 
  still 
  be 
  

   affected 
  in 
  a 
  more 
  or 
  less 
  manifest 
  degree, 
  but 
  

   the 
  number 
  of 
  converted 
  stamens 
  of 
  the 
  flower 
  

   has 
  been 
  definitely 
  fixed. 
  The 
  sensitive 
  period 
  

   has 
  terminated. 
  

  

  In 
  order 
  to 
  determine 
  the 
  exact 
  moment 
  of 
  

   this 
  termination 
  of 
  the 
  period 
  of 
  sensibility, 
  I 
  

   have 
  followed 
  the 
  development 
  of 
  the 
  flower- 
  

   buds 
  during 
  the 
  first 
  weeks 
  of 
  the 
  life 
  of 
  the 
  

   young 
  plants. 
  The 
  terminal 
  flower 
  may 
  al- 
  

   ready 
  be 
  seen 
  in 
  young 
  plants 
  only 
  seven 
  weeks 
  

   old, 
  with 
  a 
  stem 
  not 
  exceeding 
  5-6 
  cm. 
  in 
  

   height 
  and 
  a 
  flower-bud 
  with 
  a 
  diameter 
  of 
  

   nearly 
  1mm., 
  in 
  which 
  the 
  stamens 
  and 
  sec- 
  

   ondary 
  pistils 
  are 
  already 
  discernible, 
  but 
  still 
  

   in 
  the 
  condition 
  of 
  small 
  rounded 
  protuberances 
  

   on 
  the 
  thalamus. 
  Though 
  it 
  is 
  not 
  possible 
  at 
  

   that 
  time 
  to 
  observe 
  any 
  difference 
  between 
  the 
  

   future 
  normal 
  and 
  converted 
  stamens, 
  it 
  does 
  

   not 
  seem 
  doubtful 
  that 
  the 
  development 
  is 
  so 
  far 
  

   advanced, 
  that 
  in 
  the 
  inner 
  tissues 
  the 
  decision 
  

   has 
  already 
  definitely 
  been 
  taken. 
  In 
  the 
  next 
  

   few 
  days 
  this 
  decision 
  rapidly 
  becomes 
  vis- 
  

   ible, 
  and 
  the 
  different 
  parts 
  of 
  the 
  normal 
  

   stamens 
  and 
  the 
  metamorphosed 
  carpels 
  soon 
  

   become 
  apparent. 
  From 
  this 
  observation 
  it 
  

  

  