Chap. XVI.] THE YOUNG LIKE ADULTS OF SAME SEX. 209 



males during the breeding-season having been limited in 

 their transmission to the corresponding season. When 

 the adults have a distinct summer and winter plumage, 

 and the young difier from both, the case is more difficult 

 to understand. We may admit as probable that the 

 young have retained an ancient state of plumage ; we can 

 account through sexual selection for the summer or nup- 

 tial plumage of the adults, but how are we to account for 

 their distinct winter plumage ? K we could admit that 

 this plumage serves in all cases as a protection, its ac- 

 quirement would be a simple affair ; but there seems no 

 good reason for this admission. It may be suggested that 

 the widely-different conditions of life during the winter 

 and summer have acted in a direct manner on the plu- 

 mage ; this may have had some effect, but I have not 

 much confidence in so great a difference, as we sometimes 

 see, between the two plumages having been thus caused, 

 A more probable explanation is, that an ancient style of 

 plumage, partially modified through the transference of 

 some characters from the summer plumage, has been re- 

 tained by the adults during the winter. Finally, all the 

 cases in our present class apparently depend on charac- 

 ters acquired by the adult males, having been variously 

 limited in their transmission according to age, season, and 

 sex ; but it would not be worth while to attempt to fol- 

 low out these complex relations. 



Class VI. The young in their first plumage differ 

 from each other according to sex / the young males re- 

 sembling more or less closely the adult males, and the 

 young females more or less closely the adult fem,ales. — 

 The cases in the present class, though occurring in vari- 

 ous groups, are not numerous ; yet, if experience had not 

 taught us to the contrary, it seems the most natural thing 

 that the young should at first always resemble to a cer- 

 tain extent, and gradually become more and more like, the 



