8 INHERITANCE, FERTILITY, AND SEX IN PIGEONS. 



advantage M>me of the most interesting phenomena of heredity, and I am 

 convinced that this is the kind of material now most needed in attacking the all- 

 embracing subject of (lie evolution of species. 



The wild species of pigeons, in themselves and in connection with the domestic 

 pigeons, offer a boundless field for the experimental study of variation and heredity. 

 The many and closely grading species, with many sharply defined characters; the 

 wide range of fertility, adapted to many modes and lines of experiment; the per- 

 fection and ease of control; the fulness and extent of the background of knowledge 

 available in many cases; the possibility of knowing in advance the main facts of 

 ancestry and the position of the species in the genealogical tree of the group, arc 

 all important advantages for such study. (A 1/7) 



