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  Elementary 
  Species 
  

  

  Some 
  years 
  later 
  Patrick 
  Shirreff 
  described 
  his 
  

   experiments 
  and 
  results 
  in 
  a 
  paper 
  entitled, 
  

   " 
  On 
  the 
  improvement 
  of 
  cereals,' 
  but 
  the 
  de- 
  

   scriptions 
  are 
  very 
  short, 
  and 
  give 
  few 
  details 
  

   of 
  systematic 
  value. 
  The 
  leading 
  principle, 
  

   however, 
  is 
  clearly 
  indicated, 
  and 
  anyone 
  who 
  

   studies 
  with 
  care 
  his 
  method 
  of 
  working, 
  may 
  

   confidently 
  attempt 
  to 
  improve 
  the 
  varieties 
  of 
  

   his 
  own 
  locality 
  in 
  the 
  same 
  way. 
  

  

  This 
  great 
  principle 
  of 
  i 
  ' 
  variety-testing, 
  ' 
  ' 
  as 
  

   it 
  has 
  been 
  founded 
  by 
  Le 
  Couteur 
  and 
  Patrick 
  

   Shirreff, 
  has 
  increased 
  in 
  importance 
  ever 
  since. 
  

   Two 
  main 
  features 
  are 
  to 
  be 
  considered 
  here. 
  

   One 
  is 
  the 
  production 
  of 
  local 
  races, 
  the 
  other 
  

   the 
  choice 
  of 
  the 
  best 
  starting-point 
  for 
  hybrid- 
  

   izing 
  experiments, 
  as 
  is 
  shown 
  in 
  California 
  

   by 
  the 
  work 
  of 
  Luther 
  Burbank 
  in 
  crossing 
  dif- 
  

   ferent 
  elementary 
  species 
  of 
  Lilium 
  pardali- 
  

   num 
  and 
  others. 
  

  

  Every 
  region 
  and 
  locality 
  has 
  its 
  own 
  condi- 
  

   tions 
  of 
  climate 
  and 
  soil. 
  Any 
  ordinary 
  mixed 
  

   race 
  will 
  contain 
  some 
  elementary 
  forms 
  which 
  

   are 
  better 
  adapted 
  to 
  a 
  given 
  district, 
  while 
  

   others 
  are 
  more 
  suitable 
  to 
  divergent 
  condi- 
  

   tions. 
  Hence 
  it 
  can 
  readily 
  be 
  inferred 
  that 
  

   the 
  choice 
  cannot 
  be 
  the 
  same 
  for 
  different 
  re- 
  

   gions. 
  Every 
  region 
  should 
  select 
  its 
  own 
  type 
  

   from 
  among 
  the 
  various 
  forms, 
  and 
  variety- 
  

   testing 
  therefore 
  becomes 
  a 
  task 
  which 
  every 
  

  

  