1896.] NATURAL SCIENCES OF PHILADELPHIA. 121 



summer in which the bird is hatched. In such a species then, there 

 are only three plumages : 1. First Plumage. 2. Winter Plumage. 

 3. Nuptial Plumage ; — the latter being acquired in early spring, 

 either by actual molt or abrasion. Sometimes it is so like the winter 

 plumage that they can scarcely be distinguished, but this is the 

 exception, for even when no molt takes place, the abrasion gives 

 such a different appearance to the plumage by wearing off the 

 blending shades that the spring and fall birds can easily be separ- 

 ated. 



In other species the winter plumage of the young bird is not 

 absolutely like that of the adult, every shade of difference existing 

 from those that are scarcely se2:)arable to those that are radically 

 difllerent. 



In such cases there are, of course, four or five recognizable plum- 

 ages: 1. First Plumage. 2. Plumage of First Winter. 3. Plum- 

 age of First Nuptial season. 4. Adult AVinter Plumage. 5. Adult 

 Nuptial Plumage. In most species the Adult Nuptial Plumage is 

 assumed at the first spring molt, in which case there will be only four 

 distinct plumages. Sometimes the number of plumages is still further 

 increased by the fact that the bird does not acquire the complete 

 adult dress for three or four years. The changes, however, do not 

 progress as regularly in these instances after the first year, a greater 

 or less amount of the adult plumage being assumed at each molt 

 by different individuals ; so that a large series instead of being 

 divisable into several lots, each characterized by distinctive marks, 

 represents on the contrary a complete gradation from the bird of the 

 year to the adult. Such instances have been made to serve as 

 examples of the alleged change of plumage by direct change in the 

 coloration of the feathers. 



Another point bearing upon the plumages of species that require 

 several years to acquire the mature dress, is the question whether 

 there are not some individuals which never do acquire this plumage. 

 The fact of the remarkably small proportion of birds in fully adult 

 plumage in such species as the Purple Finch, Pine Grosbeak, White- 

 throated Sparrow, etc., lends weight to such a theory, although its 

 actual demonstration is, perhaps, impossible. 



Then again, there are occasional peculiar plumages, which, though 

 they may be abnormal, are nevertheless by no means unique, such 

 as the bright orange plumage of the male Scarlet Tanager, the 

 Black-headed plumage of the female Rose-breasted Grosbeak, and 



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