Chap. XIV.] GRADATION OF CHARACTERS. 135 



We may picture to ourselves a progenitor of the peacock 

 in an almost exactly intermediate condition between the 

 existing peacock, with his enormously elongated tail-cov- 

 erts, ornamented with single ocelli, and an ordinary gal- 

 linaceous bird with short tail-coverts, merely spotted with 

 some color; and we shall then see in our mind's eye a 

 bird possessing tail-coverts, capable of erection and ex- 

 pansion, ornamented 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 cen- 

 tral disk and surrounding zones of the ocellus in both sjie- 

 cies of peacock, seems to me to speak plainly in favor of 

 this view ; and this structure is otherwise inexplicable. 

 The males of Polyplectron are no doubt very beautiful 

 birds, but their beauty, when viewed from a little dis- 

 tance, cannot be compared, as I formerly saw in the Zoo- 

 logical Gardens, with that of the peacock. Many female 

 progenitors of the peacock must, during a long line of de- 

 scent, have appreciated this superiority ; for they have 

 unconsciously, by the continued preference of the most 

 beautiful males, rendered the peacock the most splendid 

 of living birds. 



Argus Pheasant. — Another excellent case for investi- 

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

 Argus pheasant, which are shaded in so wonderful a man- 

 ner as to resemble balls lying within sockets, and which 

 consequently differ from ordinary ocelli. No one, I pre- 

 sume, will attribute the shading, which has excited the ad- 

 miration of many experienced artists, to chance — to the 

 fortuitous concourse of atoms of coloring matter. That 

 these ornaments should have been foi*med thi-ough the 

 selection of many successive variations, not one of which 

 was ox'iginally intended to produce the ball-and-socket 



