﻿Double 
  Adaptations 
  431 
  

  

  had 
  to 
  be 
  studied 
  anew. 
  A 
  clear 
  analogy 
  be- 
  

   tween 
  them 
  and 
  corresponding 
  types 
  of 
  wild 
  

   plants 
  has 
  yet 
  to 
  be 
  pointed 
  out. 
  There 
  can 
  be 
  

   no 
  doubt 
  that 
  such 
  analogy 
  exists; 
  the 
  concep- 
  

   tion 
  that 
  they 
  should 
  be 
  limited 
  to 
  cultivated 
  

   plants 
  is 
  not 
  probable. 
  Striped 
  flowers 
  and 
  va- 
  

   riegated 
  leaves, 
  changes 
  of 
  stamens 
  into 
  carpels 
  

   or 
  into 
  petals 
  may 
  be 
  extremely 
  rare 
  in 
  the 
  wild 
  

   state, 
  but 
  the 
  ' 
  i 
  five-leaved 
  ' 
  clover 
  and 
  a 
  large 
  

   number 
  of 
  monstrosities 
  cannot 
  be 
  said 
  to 
  be 
  

   typical 
  of 
  the 
  cultivated 
  condition. 
  These, 
  how- 
  

   ever, 
  are 
  of 
  rare 
  occurrence, 
  and 
  do 
  not 
  play 
  

   any 
  important 
  part 
  in 
  the 
  economy 
  of 
  nature. 
  

   In 
  order 
  to 
  attain 
  a 
  better 
  solution 
  of 
  the 
  

   problem 
  we 
  must 
  take 
  a 
  broader 
  view 
  of 
  

   the 
  facts. 
  The 
  wide 
  range 
  of 
  variability 
  of 
  

   ever-sporting 
  varieties 
  is 
  due 
  to 
  the 
  presence 
  of 
  

   two 
  antagonistic 
  characters 
  which 
  cannot 
  be 
  

   evolved 
  at 
  the 
  same 
  time 
  and 
  in 
  the 
  same 
  or- 
  

   gan, 
  because 
  they 
  exclude 
  one 
  another. 
  When- 
  

   ever 
  one 
  is 
  active, 
  the 
  other 
  must 
  be 
  latent. 
  But 
  

   latency 
  is 
  not 
  absolute 
  inactivity 
  and 
  may 
  often 
  

   only 
  operate 
  to 
  encumber 
  the 
  evolution 
  of 
  the 
  

   antagonistic 
  character, 
  and 
  to 
  produce 
  large 
  

   numbers 
  of 
  lesser 
  grades 
  of 
  its 
  development. 
  

   The 
  antagonism 
  however, 
  is 
  not 
  such 
  in 
  the 
  ex- 
  

   act 
  meaning 
  of 
  the 
  word 
  ; 
  it 
  is 
  rather 
  a 
  mutual 
  

   exclusion, 
  because 
  one 
  of 
  the 
  opponents 
  simply 
  

   takes 
  the 
  place 
  of 
  the 
  other 
  when 
  absent, 
  or 
  sup- 
  

  

  