COURTSHIP IN BIRDS 253 



may dictate." In another place he says: "The 

 frills and furbelows" — crests, vivid hues, etc., 

 can — "be traced to the stimulating action of 

 the 'hormones' which control both pigmentation 

 and structure, as is shown by the fact that both 

 are modified by any interference with the glands 

 in question. Such ornamental features are then 

 the concomitants, not the result, of sexual selec- 

 tion," and again "sexual selection, other things 

 being equal, operates by according the greatest 

 number of descendents to the most amorous and 

 not necessarily to those of the highest hues." 

 He is therefore willing to admit that amorous 

 behavior by song and dance and display of plum- 

 age influence and attract the female but he ob- 

 jects to the bold statement that she selects the 

 male. Such mental qualifications satisfy those 

 who would cast aside Darwin's theory of sexual 

 selection, but after all is said this theory, if not 

 taken too literally, explains the facts better than 

 any other. It is not necessary to assume that the 

 female critically examines the display of color, 

 dance or song of the rivals and balances them 

 in her mind, but if we admit, as Pycraft is will- 



