﻿Double 
  Adaptations 
  441 
  

  

  procumbent, 
  the 
  flowers 
  being 
  large 
  and 
  of 
  a 
  

   deep 
  yellow. 
  At 
  Cadeac 
  and 
  at 
  Paris 
  the 
  whole 
  

   plant 
  changed 
  at 
  once, 
  the 
  shoots 
  becoming 
  

   elongated 
  and 
  loose, 
  with 
  broad 
  and 
  flattened, 
  

   rather 
  smooth 
  leaves 
  and 
  numerous 
  pale-hued 
  

   flowers. 
  The 
  anatomical 
  structure 
  exhibited 
  cor- 
  

   responding 
  differences, 
  the 
  intercellular 
  spaces 
  

   being 
  small 
  in 
  the 
  alpine 
  plant 
  and 
  large 
  in 
  the 
  

   one 
  grown 
  in 
  the 
  lowlands, 
  the 
  wood-tissues 
  

   strong 
  in 
  the 
  first 
  and 
  weak 
  in 
  the 
  second 
  case. 
  

  

  The 
  milfoil 
  (Acliillea 
  Mille 
  folium) 
  served 
  

   as 
  a 
  second 
  example, 
  and 
  the 
  experiments 
  were 
  

   carried 
  on 
  in 
  the 
  same 
  localities. 
  The 
  long 
  and 
  

   thick 
  rootstocks 
  of 
  the 
  alpine 
  plant 
  bearing 
  

   short 
  stems 
  only 
  with 
  a 
  few 
  dense 
  corymbs 
  

   contrasted 
  markedly 
  with 
  the 
  slender 
  stems, 
  

   loose 
  foliage 
  and 
  rich 
  groups 
  of 
  flowerheads 
  of 
  

   the 
  lowland 
  plant. 
  The 
  same 
  differences 
  in 
  in- 
  

   ner 
  and 
  outer 
  structures 
  were 
  observed 
  in 
  nu- 
  

   merous 
  instances, 
  showing 
  that 
  the 
  alpine 
  type 
  

   in 
  these 
  cases 
  is 
  dependent 
  on 
  the 
  climate, 
  and 
  

   that 
  the 
  capacity 
  for 
  assuming 
  the 
  antagonistic 
  

   characters 
  is 
  present 
  in 
  every 
  individual 
  of 
  the 
  

   species. 
  The 
  external 
  conditions 
  decide 
  which 
  

   of 
  them 
  becomes 
  active 
  and 
  which 
  remains 
  in- 
  

   active, 
  and 
  the 
  case 
  seems 
  to 
  be 
  exactly 
  paral- 
  

   lel 
  to 
  that 
  of 
  the 
  water-persicaria. 
  

  

  In 
  the 
  experiments 
  of 
  Bonnier 
  the 
  influence 
  

   of 
  the 
  soil 
  was, 
  as 
  a 
  rule, 
  excluded 
  by 
  trans- 
  

  

  