CiiAi'. XVI. Birds— Novelty admired. 495 



coloured. I infer that this would be the case, from the analogy 

 of many other birds, which are dark whilst young, and when 

 ftdult are white ; and more especially from the case of the Ai dw 

 gularis, the colours of which are the reverse of those of A. ushu, 

 for the young are dark-coloured and the adults white, the young 

 Having retained a former state of plumage. It appears there- 

 fore that, during a long line of descent, the adult progenitors 

 of the Ardea asha, the Buphus, and of some allies, have under- 

 gone the following changes of colour : fiist, a dark shade ; 

 bdcondly, pure white ; and thirdly, owing to another change of 

 fashion (if I may so express myself), their present slaty, reddish, 

 or golden-buff tints. These successive changes are intelligible 

 only on the principle of novelty having been admired by birds 

 fur its own sake. 



Several writers have objected to the whole theory of sexual 

 selection, by assuming that with animals and savages the 

 taste of the female for certain colours or other ornaments 

 would not remain constant for many generations; that first 

 one colour and then another would be admired, and con- 

 sequently that no permanent effect could be produced. We may 

 admit that taste is fluctuating, but it is not quite arbitrary. It 

 depends much on habit, as we see in mankind ; and we may 

 inter that this would hold good with birds and other animals. 

 Even in our own dress, the general character lasts long, and the 

 changes are to a certain extent graduated. Abundant evidence 

 will be given in two places in a future chapter, that savages 

 of many races have admired for many generations the same 

 cicatrices on the skin, the same hideously perforated lips, 

 nostrils, or ears, distorted heads, &c. ; and these deformities 

 present some analogy to the natural ornaments of various 

 animals. Nevertheless, with savages such fashions do not endure 

 for ever, as we may infer from the differences in this respect 

 between allied tribes on the same continent. So again the raisers 

 of fancy animals certainly have admired for many generations 

 and still admire the same breeds ; they earnestly desire slight 

 changes, which are considered as improvements, but any great or 

 sudden change is looked at as the greatest blemish. With birds 

 in a state of nature we have no reason to suppose that they 

 would admire an entirely new style of coloration, even if great 

 and sudden variations often occurred, which is far from being 

 the case. We know that dovecot pigeons do not willingly 

 associate with the variously coloured fancy breeds ; that albino 

 birds do not commonly get partners in marriage ; and that the 

 black ravens of the Peroe Islands chase away their piebald 

 brethren. But this dislike of a sudden change would not 



