﻿Theories 
  of 
  Evolution 
  27 
  

  

  sown. 
  Cultivated 
  plants 
  of 
  course, 
  had 
  only 
  

   a 
  small 
  chance 
  to 
  exhibit 
  new 
  qualities, 
  as 
  they 
  

   have 
  been 
  so 
  strictly 
  controlled 
  during 
  so 
  many 
  

   years. 
  Moreover 
  their 
  purity 
  of 
  origin 
  is 
  in 
  

   many 
  cases 
  doubtful. 
  Among 
  wild 
  plants 
  only 
  

   those 
  could 
  be 
  expected 
  to 
  reward 
  the 
  investi- 
  

   gator 
  which 
  were 
  of 
  easy 
  cultivation. 
  For 
  this 
  

   reason 
  I 
  have 
  limited 
  myself 
  to 
  the 
  trial 
  of 
  wild 
  

   plants 
  of 
  Holland, 
  and 
  have 
  had 
  the 
  good 
  for- 
  

   tune 
  to 
  find 
  among 
  them 
  at 
  least 
  one 
  species 
  in 
  a 
  

   state 
  of 
  mutability. 
  It 
  was 
  not 
  really 
  a 
  native 
  

   plant, 
  but 
  one 
  that 
  had 
  been 
  introduced 
  from 
  

   America 
  and 
  belongs 
  to 
  an 
  American 
  genus. 
  I 
  

   refer 
  to 
  the 
  great 
  evening-primrose 
  or 
  the 
  even- 
  

   ing-primrose 
  of 
  Lamarck. 
  A 
  strain 
  of 
  this 
  

   beautiful 
  species 
  is 
  growing 
  in 
  an 
  abandoned 
  

   field 
  in 
  the 
  vicinity 
  of 
  Hilversum, 
  at 
  a 
  short 
  dis- 
  

   tance 
  from 
  Amsterdam. 
  Here 
  it 
  has 
  escaped 
  

   from 
  a 
  park 
  and 
  multiplied. 
  In 
  doing 
  so 
  it 
  has 
  

   produced 
  and 
  is 
  still 
  producing 
  quite 
  a 
  number 
  

   of 
  new 
  types, 
  some 
  of 
  which 
  may 
  be 
  considered 
  

   as 
  retrograde 
  varieties, 
  while 
  others 
  evidently 
  

   are 
  of 
  the 
  nature 
  of 
  progressive 
  elementary 
  

   species. 
  

  

  This 
  interesting 
  plant 
  has 
  Afforded 
  me 
  the 
  

   means 
  of 
  observing 
  directly 
  how 
  new 
  species 
  

   originate, 
  and 
  of 
  studying 
  the 
  laws 
  of 
  these 
  

   changes. 
  My 
  researches 
  have 
  followed 
  a 
  double 
  

   line 
  of 
  inquiry. 
  On 
  one 
  side, 
  I 
  have 
  limited 
  

  

  