﻿62 
  Elementary 
  Species 
  

  

  genera, 
  are 
  equally 
  artificial 
  or 
  conventional. 
  

   In 
  other 
  words 
  we 
  may 
  state 
  " 
  that 
  current 
  

   misconceptions 
  as 
  to 
  the 
  extreme 
  range 
  of 
  fluc- 
  

   tuating 
  variability 
  of 
  many 
  native 
  species 
  have 
  

   generally 
  arisen 
  from 
  a 
  failure 
  to 
  recognize 
  the 
  

   composite 
  nature 
  of 
  the 
  forms 
  in 
  question, 
  " 
  as 
  

   has 
  been 
  demonstrated 
  by 
  MacDougal 
  in 
  the 
  

   case 
  of 
  the 
  common 
  evening-primrose, 
  Oeno- 
  

   thera 
  biennis. 
  " 
  It 
  is 
  evident 
  that 
  to 
  study 
  the 
  

   behavior 
  of 
  the 
  characters 
  of 
  plants 
  we 
  must 
  

   have 
  them 
  in 
  their 
  simplest 
  combinations; 
  to 
  

   investigate 
  the 
  origin 
  and 
  movements 
  of 
  species 
  

   we 
  must 
  deal 
  with 
  them 
  singly 
  and 
  uncompli- 
  

   cated." 
  

  

  