Chap. XIV. GRADATION OF CHARACTERS. 141 



is needed. We may picture to ourselves a progenitor 

 of the peacock in an almost exactly intermediate con- 

 dition between the existing peacock, with his enor- 

 mously elongated tail-coverts, ornamented with single 

 ocelli, and an ordinary gallinaceous bird with short 

 tail-coverts, merely spotted with some colour; and we 

 shall then see in our mind's eye, a bird possessing 

 tail-coverts, capable of erection and expansion, orna- 

 mented with two partially confluent ocelli, and long 

 enough almost to conceal the tail-feathers, — the latter 

 having already partially lost their ocelli ; we shall 

 see in short, a Polyplectron. The indentation of the 

 central disc and surrounding zones of the ocellus in both 

 species of peacock, seems to me to speak plainly in 

 favour of this view ; and this structure is otherwise inex- 

 plicable. The males of Polyplectron are no doubt very 

 beautiful birds, but their beauty, when viewed from a 

 little distance, cannot be compared, as I formerly saw 

 in the Zoological Gardens, with that of the peacock. 

 Many female progenitors of the peacock must, during 

 a long line of descent, have appreciated this superiority; 

 for they have unconsciously, by the continued prefer- 

 ence of the most beautiful males, rendered the peacock 

 the most splendid of living birds. 



Argus pheasant. — Another excellent case for investi- 

 gation is offered by the ocelli on the wing-feathers of 

 the Argus pheasant, which are shaded in so wonderful a 

 manner as to resemble balls lying within sockets, and 

 which consequently differ from ordinary ocelli. No one, 

 I presume, will attribute the shading, which has excited 

 the admiration of many experienced artists, to chance 

 — to the fortuitous concourse of atoms of colouriDg 

 matter. That these ornaments should have been formed 

 through the selection of many successive variations, not 

 one of which was originally intended to produce the 



