280 CALIFORNIA ACADJEMY OF SCIENCES. 



or are now at the climax of their development. Dryo- 

 bates, Xenopicus and Picoides belong to the former 

 class and Sphyrapicus, Melanerpes, and Colaptes to the 

 latter. It is doubtful where Campephilus and Ceoph- 

 loeus should be placed in tnis scale. This loss of brilliant 

 color in certain genera is demonstrated by the fact that 

 the young are more brightly colored than the adult — a 

 very unusual state of affairs. This is particularly notice- 

 able in Dryobates where the young male has the entire 

 top of the head scarlet, this color being restricted in the 

 adult to a narrow-patch on the nape. As this excess of 

 red in the young cannot be of any conceivable utility it 

 seems to afford a perfect demonstration of the former 

 plumage of the adult. Furthermore, in certain forms, 

 particularly in the genus Melanerpes, an excess of red or 

 yellow, or both, very frequently occurs on the breast and 

 belly. If the amount were very slight and occasional, 

 it might be looked upon as an excess of pigmentation 

 along the line of future color development. From the 

 frequency with which it occurs, however, and its in- 

 tensity in some instances, it seems more probable that 

 it is a character which is being rapidly lost at the present 

 time. It seems probable that the American species of 

 Dryobates also had the belly colored red in past times, 

 for in certain Asiatic species which have the red head 

 like the young of American forms, the belly is also more 

 or less strongly tinged with red. It would seem then 

 that Melanerpes had but recently passed the climax of 

 its most brilliant coloration, while Dryobates must have 

 long since donned the garb of old age. It seems a 

 rather curious circumstance that birds such as the wood- 

 peckers, which habitually cling close to the trunks of 

 trees, should have a bright color upon the abdomen. 

 May it not be possible that this plumage was assumed 

 before the tree climbing habit was acquired, and is now 



