1896.] NATURAL SCIENCES OF PHILADELPHIA. 145 



that of the old birds except in the purity and extent of the chestnut 

 crown. In spring the dusky feathers of the throat are replaced by 

 pure white ones and those of the crown by new ones, which are 

 richly colored and have no dark spots. Apparently the older birds 

 do not molt at all in spring, the pure chestnut crown being gained 

 entirely by abrasion of the dusky tips of the feathers. Adults vary, 

 however, in the purity of the chestnut crown acquired at the annual 

 molt, some of them showing much mottling of brown. In con- 

 sequence of this a partial spring molt may be necessary in some 

 individuals after the. first season. Some change is effected in the 

 other plumage during spring and winter by abrasion. 



Spizella pusilla (Wils.). Field Sparrow. 



Plumages, first, winter and nuptial. 



After the annual molt the winter plumage changes gradually by 

 abrasion, and there is no spring molt except the occasional renewal 

 of odd feathers. The contrast between October and August spec- 

 imens is striking. The former have the back buff with reddish- 

 brown centers and black shaft streaks, while the latter have reddish- 

 brown backs with distinct black streaks. 



Junco hyemalis (Linn.). Snow Bird. 



Plumages, first, winter, nuptial. 



No spring molt is apparent in the Snow Bird. The brown tints 

 of autumn disappear entirely through abrasion, but this is not 

 marked until after May 1st. Birds of the year are probably always 

 browner than old birds. 



Melospiza fasciata (Gmel.). Song Sparrow. 



Plumages, first, winter, nuptial. 



No spring molt occurs but abrasion is very marked, all the buff 

 tints being lost in the spring bird,^ while the black streaks on the 

 breast appear as if their ends had been cut off with a pair of scissors. 

 Melospiza georgiana (Lath.). Swamp Sparrow. 



Male. — Plumages, first, winter, nuptial. 



The molt of this species appears to be precisely like that of Spizella 

 socialis, which it so closely resembles in the pattern of its plumage. 

 The chestnut crown is acquired in spring as well as a certain pro- 

 portion of white throat feathers. The chestnut crown once acquired 

 is not lost at the annual molt but some individuals do not seem to 

 acquire it in its entirety, at least until the second year. No spring 

 molt seems to occur after the full chestnut crown is attained. As 



