98 INHERITANCE OF CHARACTERISTICS IN DOMESTIC FOWL. 



fact of hybridization it indicates that the main problem of evolution is 

 that of the origin of specific characteristics. A character, once arisen in 

 an individual, may become a part of any species with which that individual 

 can hybridize. Given the successive origin of the characters A,B,C, D, E, F, 

 in various individuals capable of intergenerating with the mass of the species, 

 it is clear that such characters would in time become similarly combined 

 on many individuals; and the similar individuals, taken together, would 

 constitute a new species. The adjustment of the species would be per- 

 fected by the elimination of such combinations as were disadvantageous. 



Cold Spring Harbor, New York, 



May 20, 1909. 



