360 LUTHER BURBANK 



the less fit on the other, may be spoken of as 

 constituting "natural selection." 



This term, natural selection, has obvious pro- 

 priety because it connotes a process closely akin 

 in its results to the artificial selection through 

 which man determines that certain races of ani- 

 mals and plants under domestication shall be 

 preserved, and that others shall be destroyed. 

 But artificial selection is after all only a phase 

 of natural selection, in which a man becomes 

 an active influence or a deciding element in 

 environment. 



Because of man's power to transform the con- 

 ditions of soil, to supply artificial heat, and to 

 bring together and hybridize plants and animals 

 that would not come in contact in the state of 

 nature, the results of artificial selection, epito- 

 mizing within certain bounds the results of 

 natural selection, may be produced with un- 

 exampled celerity. 



Man, for example, eliminates a species in a 

 few decades, where nature would have found no 

 way of correspondingly rapid elimination. The 

 black walnut, for example, has been almost 

 exterminated throughout eastern America be- 

 cause man prized its wood for the making of 

 furniture. But for the presence of civilized man 

 the black walnut would doubtless have main- 



