BIRDS— YOUNG LIKE BOTH ADULTS. 481 



occurrence, in their summer dress; thirdly, they may he inter- 

 mediate between these two states; and, fourthly, they may ditfer 

 greatly from the adults at all seasons. We have an instance of 

 the first of these four cases in one of the egrets of India (Buphus 

 coromandus), in which the young and the adults of both sexes 

 are white during the winter, the. adults becoming golden-butt 

 during the summer. With the gaper (Anastomus oscitans) of 

 India we have a similar case, but the colors are revefSed: for 

 the young and the adults of both sexes are gray and black during 

 the winter, the adults becoming white during the summer." As 

 an instance of the second case, the young of the razor-bill (Alca 

 torda, Linn.), in an early state of plumage, are colored like the 

 adults during the summer; and the young of the white-crowned 

 sparrow of North America (Fringilla leucophrys), as soon as 

 fledged, have elegant white stripes on their heads, which are lost 

 I)y the young and the old during the winter." With respect to 

 the third case, namely, that of the young having an intermediate 

 character between the summer and winter adult plumages, Yar- 

 rell*' insists that this occurs with many waders. Lastly, in regard 

 to the young differing greatly from both sexes in their adult sum- 

 mer and winter plumages, this occurs with some herons and egrets 

 of North America and India, — the young alone being white. 



I will make only a few remarks on these complicated cases. 

 When the young resemble the females in their summer dress, or 

 the adults of both sexes in their winter dress, the cases differ 

 from those given under Classes I. and III. only in the characters 

 originally acquired by the males during the breeding-season, hav- 

 ing been limited in their transmission to the corresponding sea- 

 son. When the adults have a distinct summer and winter plum- 

 age, and the young differ 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 by sexual 

 selection for the summer or nuptial plumage of the adults, but 

 how are we to account for their distinct winter plumage? If we 

 could admit that this plumage serves in all cases as a protection, 

 its acquirement 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 



" I am indebted to Mr. Blyth for Information as to the Buphus; see 

 also Jerdon, 'Birds of India,' vol. iii. p. 749. On the Anastomus, see 

 Blyth, in 'Ibis,' 1807, p. 173. 



" On the Alca, see Macgillivray, 'Hist, of Brit. Birds.' vol. v. p. 347. 

 On the Fringilla leucophrys, Audubon, ibid. vol. ii. p. 89. I shall have 

 hereafter to refer to the young of certain herons and egrets being 

 white. 



« 'History of British Birds,' vol. i. 1839, p. 159. 

 32 



