208 SEXUAL SELECTION: BIRDS. [Part IL 



adulta 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 tlie adults of both 

 sexes arc white during the winter, the adults becoming 

 golden-buff during the summer. With the Gaper {Anas- 

 tomits oscitans) of India we have a similar case, but the 

 colors are reversed ; for the young and the adults of both 

 sexes are gray and black during the winter, the adults be- 

 coming 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 leuco- 

 phri/s), as soon as fledged, have elegant white stripes on 

 their heads, which are lost by the young and the old dur- 

 ing the winter.''* With respect to the third case, namely, 

 that of the young having an intermediate character be- 

 tween the summer and winter adult plumages, Yarrell " 

 insists that this occurs with many waders. Lastly, in re- 

 gard to the young differing greatly from both sexes in 

 their adult summer 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 female in her sum- 

 mer dress, or the adults of both sexes in their winter 

 dress, the cases differ from those given under Classes L 

 and III. only in the characters originally acquired by the 



■•* I am indebted to Mr. Blyth for information in regard to the 

 Buphus : see also Jerdon, ' Birds of India,' vol. iiL p. 749. On the 

 Anastomus, see Blyth, in 'Ibis,' 1867, p. 173. 



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

 On the FringUla Icucophrys, Audubon, ibid. vol. iL p. 89. I shall have 

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



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



