﻿New 
  Species 
  of 
  Oenothera 
  537 
  

  

  quite 
  constant 
  from 
  the 
  very 
  first 
  moment 
  of 
  

   their 
  appearance. 
  I 
  have 
  cultivated 
  them 
  from 
  

   seed 
  in 
  large 
  numbers, 
  and 
  they 
  have 
  never 
  re- 
  

   verted 
  to 
  the 
  lamarckiana. 
  From 
  this 
  they 
  

   have 
  inherited 
  the 
  mutability 
  or 
  the 
  capacity 
  of 
  

   producing 
  at 
  their 
  turn 
  new 
  mutants. 
  But 
  they 
  

   seem 
  to 
  have 
  done 
  so 
  incompletely, 
  changing 
  in 
  

   the 
  direction 
  of 
  more 
  absolute 
  constancy. 
  This 
  

   was 
  especially 
  observed 
  in 
  the 
  case 
  of 
  rubri- 
  

   nervis, 
  which 
  is 
  not 
  of 
  such 
  rare 
  occurrence 
  as 
  

   0. 
  gigaSj 
  and 
  which 
  it 
  has 
  been 
  possible 
  to 
  study 
  

   in 
  large 
  numbers 
  of 
  individuals. 
  So 
  for 
  in- 
  

   stance, 
  " 
  the 
  red-veins 
  : 
  have 
  never 
  produced 
  

   any 
  dwarfs, 
  notwithstanding 
  they 
  are 
  produced 
  

   very 
  often 
  by 
  the 
  parent-type. 
  And 
  in 
  crossing 
  

   experiments 
  also 
  the 
  red- 
  veins 
  gave 
  proof 
  of 
  the 
  

   absence 
  of 
  a 
  mutative 
  capacity 
  for 
  their 
  produc- 
  

   tion. 
  

  

  Leaving 
  the 
  robust 
  novelties, 
  we 
  may 
  now 
  

   take 
  up 
  a 
  couple 
  of 
  forms, 
  which 
  are 
  equally 
  

   constant, 
  and 
  differentiated 
  from 
  the 
  parent- 
  

   species 
  in 
  exactly 
  the 
  same 
  manner, 
  though 
  by 
  

   other 
  characters, 
  but 
  which 
  are 
  so 
  obviously 
  

   weak 
  as 
  to 
  have 
  no 
  manifest 
  chance 
  of 
  self- 
  

   maintenance 
  in 
  the 
  wild 
  state. 
  These 
  are 
  the 
  

   whitish 
  and 
  the 
  oblong-leaved 
  evening-prim- 
  

   roses 
  or 
  the 
  Oenothera 
  alblda 
  and 
  oblonga. 
  

  

  Oenothera 
  alblda 
  is 
  a 
  very 
  weak 
  species, 
  with 
  

   whitish, 
  narrow 
  leaves, 
  which 
  are 
  evidently 
  in- 
  

  

  