EVOLUTION OF THE COLORS OF BIRDS. 297 



from the dull gray plumage of the female by sexual se- 

 lection. White wing-bars, directive recognition marks. 



GENUS CARPODACUS. THE PURPLE FINCHES, ETC. 



It will be remembered that each of the larger Ameri- 

 can kingfishers (Ceryle) had a corresponding allied 

 smaller species (see ante, p. 278). The relation between 

 the colors of Pinicola and Carpodacus seems to be a 

 similar one, although less direct. The relative colors of 

 the sexes and young, as well as the absolute colors of 

 these two genera, are very similar, and undoubtedly had 

 a common origin and were developed by the same 

 agencies. In speaking of the scarlet rose finch (C. ery- 

 thrinus grebnitskii), Dr. Stejneger says:* " There can 

 be no doubt that males of this species breed in the gray 

 plumage. I found these breeding gray males almost as 

 common in Petropaulski as the red ones, their conduct 

 and song being exactly the same as that of the latter, 

 and dissection showed that the genital organs were well 

 developed and fully matured. It seems to be a question 

 whether these mature gray birds will ever assume the 

 red plumage, and I should be most inclined to believe 

 that we have here to do with a kind of dichromatisin." 

 May not this tendency towards dichromatism in Carpo- 

 dacus be parallel to the phases of coloration in Pinicola 

 noticed by Mr. Kidgway in the following note in the 

 Manual of North American Birds:f " Apparently adult 

 males are occasionally found in which the plumage is 

 not distinguishable from that of the female; in others 

 the general plumage is that of the female, except that 

 the olivaceous or tawny color on head, etc., is replaced 

 by a more reddish tint (varying from light dull orange- 

 red to deep madder-brown)." 



* Bull. U. S. Nat. Mus. 29, p. 266. 

 tpp. 387-388. 



