282 CALIFORNIA ACADEMY OF SCEENCES. 



marks were it not for the remarkable indiscriminate 

 breeding between the two species, apparently with no 

 deleterious result to the species.* The red of the western 

 species is apparently the correlative of the yellow of C. 

 auratus, and is due to some form of pigment intensifica- 

 tion more than to selection. Mr. Frank M. Chapman 

 has published a note On the Color-Pattern of the Upper 

 Tail-Coverts in Colaptes auratus,^ illustrated with cuts 

 of the feather, in which he shows that the barred pattern 

 is the earliest form of marking, culminating in a solid 

 black feather, rimmed with light. It is an interesting 

 .fact that the circular spots on the side are modifications 

 of the barred feather, as is shown by a study of the 

 successional taxology of the feathers on the lower part 

 of the body, the barred type being posterior to the cir- 

 cular. The fact that although Colaptes does not present 

 #n obviously barred plumage the specialized markings 

 have all been developed from the bar, taken in connec- 

 tion with the frequency of barred markings throughout 

 the woodpecker family would seem to indicate that the 

 common ancestor of the group had been a strongly 

 barred form, these markings having continued to the 

 species of to-day with greater or less persistence. 



Figs. 4 and 5 of Plate I show the typical markings of 

 the Dryobates villosus and D. scalaris groups, the striped 

 and barred forms. In this instance the difference be- 

 tween a streak and a stripe may be illustrated. In a 

 streaked plumage the pigmentation is generally along 

 the line of the shaft, and is the most primitive style of 

 marking. A striped plumage is produced in a much 

 bolder manner and is not necessarily a primitive form. 



* cf. The North American Species of the Genus Colaptes, considered 

 with Special Keference to the Relationship of C. auratus and C. Cafer. 

 J. A. Allen. Bull. Am. Mus. Nat. Hist., iv, pp. 21-44. 



t Bull. Am. Mus. Nat. Hist., iii, pp. 311-314. 



