382 LUTHER BURBANK 



that the influence of the single new factor should 

 greatly change the aggregate result. 



In this view, what we term a species is a com- 

 pany of organisms in the germ plasm of which 

 the groups of factors for each main character- 

 istic have become purely and unqualifiedly reces- 

 sive, so that they act as a unit in producing a 

 given character. They thus determine the chief 

 characteristics of heredity in the Darwinian 

 sense, which finds its popular expression in the 

 phrase "like produces like." 



Meantime, there are always minor groups of 

 newer characters that are striving for recogni- 

 tion, and while these are relatively insignificant 

 because of their newness and small number as 

 compared with the whole, yet they are conspicu- 

 ous and important in the eyes of the plant de- 

 veloper because they represent precisely those 

 modifications of form and constitution and 

 color that mark what we speak of as variations 

 from type; and because they are so matched 

 against one another in heredity in the manner 

 that we call Mendelian as to make it possible 

 for the plant developer to segregate and recom- 

 bine them variously by hybridizing, and thus to 

 develop new races from the old stock. 



When, however, the plant developer, through 

 his hybridizing experiments, brings together 



