Chap. XYI.] NOVELTY ADMIRED. 221 



head. 57 As so many male birds have for their chief orna- 

 ment elongated tail-feathers or elongated crests, the short- 

 ened tail, formerly described in the male of a humming- 

 bird, and the shortened crest of the male goosander almost 

 seem like one of the many opposite changes of fashion 

 which we admire in our own dresses. 



Some members of the heron family offer a still more 

 curious case of novelty in coloring having apparently been 

 appreciated for the sake of novelty. The young of the 

 Ardea asha are white, the adults being dark slate-colored ; 

 and not only the young, but the adults of the allied JBuphus 

 coromandus in their winter plumage are white, this color 

 changing into a rich golden-buff during the breeding-sea- 

 son. It is incredible that the young of these two species, 

 as well as of some other members of the same family, 58 

 should have been specially rendered pure white and thus 

 made conspicuous to their enemies ; or that the adults of 

 one of these two species should have been specially ren- 

 dered white during the winter in a country which is never 

 covered with snow. On the other hand, we have reason 

 to believe that whiteness has been gained by many birds 

 as a sexual ornament. We may therefore conclude that 

 an early progenitor of the Ardea asha and the JBuphxts 

 acquired a white plumage for nuptial purposes, and trans- 

 mitted this color to their young ; so that the young and 

 the old became white like certain existing egrets; the 

 whiteness having afterward been retained by the young 

 while exchanged by the adults for more strongly-pro- 



51 See Jerdon on the genus Palaeornis, 'Birds of India,' vol. i. pp. 

 258-260. 



58 Tke young of Ardea rufescens and A. ccerulea of the United States 

 are likewise white, the adults being colored in accordance with their spe- 

 cific names. Audubon (' Ornith. Biography,' vol. iii. p. 416 ; vol. iv. p. 

 58) seems rather pleased at the thought that this remarkable change of 

 plumage will greatly " disconcert the systematists." 



