﻿102 
  Elementary 
  Species 
  

  

  the 
  races 
  is 
  a 
  condition 
  implanted 
  in 
  them 
  by 
  

   man, 
  and 
  nature 
  always 
  strives 
  against 
  this 
  

   arbitrary 
  and 
  one-sided 
  improvement. 
  Numer- 
  

   ous 
  slight 
  differences 
  in 
  characters 
  and 
  numer- 
  

   ous 
  external 
  influences 
  benefit 
  the 
  minor 
  types 
  

   and 
  bring 
  them 
  into 
  competition 
  with 
  the 
  better 
  

   ones. 
  Sometimes 
  they 
  tend 
  to 
  supplant 
  the 
  

   latter 
  wholly, 
  but 
  ordinarily 
  sooner 
  or 
  later 
  a 
  

   state 
  of 
  equilibrium 
  is 
  reached, 
  in 
  which 
  hence- 
  

   forth 
  the 
  different 
  sorts 
  may 
  live 
  together. 
  

   Some 
  are 
  favored 
  by 
  warm 
  and 
  others 
  by 
  cool 
  

   summers, 
  some 
  are 
  injured 
  by 
  hard 
  winters, 
  

   while 
  others 
  thrive 
  then 
  and 
  are 
  therefore 
  rela- 
  

   tively 
  at 
  an 
  advantage. 
  The 
  mixed 
  condition 
  

   is 
  the 
  rule, 
  purity 
  is 
  the 
  exception. 
  

  

  Different 
  sorts 
  of 
  cereals 
  are 
  not 
  always 
  

   easily 
  distinguishable 
  by 
  the 
  layman 
  and 
  there- 
  

   fore 
  I 
  will 
  draw 
  your 
  attention 
  to 
  conditions 
  in 
  

   meadows, 
  where 
  a 
  corresponding 
  phenomenon 
  

   can 
  be 
  observed 
  in 
  a 
  much 
  simpler 
  way. 
  

  

  Only 
  artificial 
  pasture-grounds 
  are 
  seen 
  to 
  

   consist 
  of 
  a 
  single 
  species 
  of 
  grass 
  or 
  clover. 
  

   The 
  natural 
  condition 
  in 
  meadows 
  is 
  the 
  occur- 
  

   rence 
  of 
  clumps 
  of 
  grasses 
  and 
  some 
  clovers, 
  

   mixed 
  up 
  with 
  perhaps 
  twenty 
  or 
  more 
  species 
  

   of 
  other 
  genera 
  and 
  families. 
  The 
  numerical 
  

   proportion 
  of 
  these 
  constituents 
  is 
  of 
  great 
  in- 
  

   terest, 
  and 
  has 
  been 
  studied 
  at 
  Rothamstead 
  in 
  

   England 
  and 
  on 
  a 
  number 
  of 
  other 
  farms. 
  It 
  is 
  

  

  