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  Retrograde 
  Varieties 
  

  

  Many 
  dark 
  flowers 
  have 
  an 
  intermediate 
  bright 
  

   hued 
  form 
  besides 
  the 
  white 
  variety, 
  as 
  in 
  the 
  

   case 
  of 
  roses, 
  asters, 
  Nicandra 
  and 
  so 
  on. 
  

  

  Intermediate 
  forms 
  with 
  respect 
  to 
  stature 
  

   may 
  also 
  be 
  seen. 
  The 
  opium-poppy, 
  the 
  snap- 
  

   dragon, 
  peas, 
  the 
  Nicandra, 
  and 
  many 
  other 
  

   garden-plants 
  have 
  not 
  only 
  dwarf 
  varieties, 
  

   but 
  also 
  some 
  of 
  intermediate 
  height. 
  These, 
  

   though 
  they 
  are 
  intermediate 
  between 
  the 
  tall 
  

   and 
  dwarf 
  types, 
  cannot 
  be 
  considered 
  as 
  transi- 
  

   tions, 
  as 
  between 
  them 
  and 
  the 
  extremes, 
  inter- 
  

   mediates 
  are, 
  as 
  a 
  rule 
  wholly 
  lacking. 
  In- 
  

   stances 
  of 
  the 
  same 
  occurrence 
  of 
  three 
  types 
  

   may 
  be 
  seen 
  in 
  the 
  seeds 
  of 
  maize 
  (" 
  Cuzco,' 
  

   " 
  Horse-dent 
  " 
  and 
  "Gracillima") 
  of 
  beans 
  and 
  

   some 
  other 
  plants. 
  The 
  Xanthium 
  Wooioni, 
  

   above 
  referred 
  to, 
  with 
  only 
  part 
  of 
  the 
  prickles 
  

   of 
  Xanthium 
  commune 
  is 
  also 
  a 
  very 
  curious 
  in- 
  

   stance 
  of 
  the 
  demonstration 
  of 
  the 
  compound 
  

   nature 
  of 
  a 
  character. 
  

  

  Summarizing 
  the 
  conclusions 
  that 
  may 
  be 
  

   drawn 
  from 
  the 
  evidence 
  given 
  in 
  this 
  lecture, 
  

   we 
  have 
  seen 
  that 
  varieties 
  differ 
  from 
  elemen- 
  

   tary 
  species 
  in 
  that 
  they 
  do 
  not 
  possess 
  anything 
  

   really 
  new. 
  They 
  originate 
  for 
  the 
  greater 
  part 
  

   in 
  a 
  negative 
  way, 
  by 
  the 
  apparent 
  loss 
  of 
  some 
  

   quality, 
  and 
  rarely 
  in 
  a 
  positive 
  manner 
  by 
  ac- 
  

   quiring 
  a 
  character, 
  already 
  seen 
  in 
  allied 
  spe- 
  

   cies. 
  These 
  characters 
  are 
  not 
  of 
  the 
  nature 
  of 
  

  

  