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  Elementary 
  Species 
  

  

  to 
  be 
  too 
  large 
  to 
  constitute 
  species. 
  Hence 
  the 
  

   polymorphous 
  genera, 
  concerning 
  the 
  syste- 
  

   matic 
  subdivisions 
  of 
  which 
  hardly 
  two 
  authors 
  

   agree. 
  Brambles 
  and 
  roses 
  are 
  widely 
  known 
  

   instances, 
  but 
  oaks, 
  elms, 
  apples, 
  and 
  pears, 
  

   Mentha, 
  Prunus, 
  Vitis, 
  Lactuca, 
  Cucumis, 
  Cu- 
  

   curbita 
  and 
  numerous 
  others 
  are 
  in 
  the 
  same 
  

   condition. 
  

  

  In 
  some 
  instances 
  the 
  existence 
  of 
  elementary 
  

   species 
  is 
  so 
  obvious, 
  that 
  they 
  have 
  been 
  de- 
  

   scribed 
  by 
  taxonomists 
  as 
  systematic 
  varieties 
  

   or 
  even 
  as 
  good 
  species. 
  The 
  primroses 
  afford 
  

   a 
  widely 
  known 
  example. 
  Linnaeus 
  called 
  them 
  

   Primula 
  veris, 
  and 
  recognized 
  three 
  types 
  as 
  

   pertaining 
  to 
  this 
  species, 
  but 
  Jacquin 
  and 
  

   others 
  have 
  elevated 
  these 
  subspecies 
  to 
  the 
  full 
  

   rank 
  of 
  species. 
  They 
  now 
  bear 
  the 
  names 
  of 
  

   Primula 
  elatior 
  with 
  larger, 
  P. 
  officinalis 
  with 
  

   smaller 
  flowers, 
  and 
  P. 
  acaulis. 
  In 
  the 
  last 
  

   named 
  the 
  common 
  flower-stalk 
  is 
  lacking 
  and 
  

   the 
  flowers 
  of 
  the 
  umbel 
  seem 
  to 
  be 
  borne 
  in 
  

   the 
  axils 
  of 
  the 
  basal 
  leaves. 
  

  

  In 
  other 
  genera 
  such 
  nearly 
  allied 
  species 
  are 
  

   more 
  or 
  less 
  universally 
  recognized. 
  Galium 
  

   Mollugo 
  has 
  been 
  divided 
  into 
  G. 
  datum 
  with 
  a 
  

   long 
  and 
  weak 
  stem, 
  and 
  G. 
  erectum 
  with 
  

   shorter 
  and 
  erect 
  stems 
  ; 
  Cochlearia 
  danica, 
  an- 
  

   glica 
  and 
  officinalis 
  are 
  so 
  nearly 
  allied 
  as 
  to 
  be 
  

   hardly 
  distinguishable. 
  Sagina 
  apetala 
  and 
  pat- 
  

  

  