116 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 ^^ variety-testing," as 

 it has been founded by Le Couteur and Patrick 

 Shirretf , 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 



