4.32 The Descent of Man. Part II. 



wing-feathers, which are ornamented with numerous ocelli. 3 

 request the reader to turn back to the drawing (fig. 51, p. 397) 

 of a Polyplectron. In P. napoleonis the ocelli are confined to 

 the tail and the back is of a rich metallic blue ; in which re- 

 spects this species approaches the Java peacock. P. Jiardwickii 

 possesses a peculiar top-knot, which is also somewhat like 

 that of the Java peacock. In all the species the ocelli on the 

 wings and tail are either circular or oval, and consist of a 

 beautiful, iridescent, greenish-blue or greenish-purple disc, with 

 a black border. This border in P. chinquis shades into brown, 

 edged with cream-colour, so that the ocellus is here surrounded 

 with variously shaded, though not bright, concentric zones. The 

 unusual length of the tail-coverts is another remarkable character 

 in Polyplectron ; for in some of the species they are half, and in 

 others two-thirds as long as the true tail-feathers. The tail- 

 coverts are ocellated as in the peacock. Thus the several species 

 of Polyplectron manifestly make a graduated approach to the 

 peacock in the length of their tail-coverts, in the zoning of the 

 ocelli, and in some other characters. 



Notwithstanding this approach, the first species of Polyplectron 

 which I examined almost made me give up the search ; for I 

 found not only that the true tail-feathers, which in the peacock 

 are quite plain, were ornamented with ocelli, but that the ocelli 

 on all the feathers differed fundamentally from those of the 

 peacock, in there being two on the same feather (fig. 55), one on 

 each side of the shaft. Hence I concluded that the early pro- 

 genitors of the peacock could not have resembled a Polyplectron. 

 But on continuing my search, I observed that in some of the 

 species the two ocelli stood very near each other; that in the 

 tail-feathers of P. Jiardwickii they touched each other; and, 

 finally, that on the tail-coverts of this same species as well as of 

 P. mulaccense (fig. 56) they were actually confluent. As the 

 central part alone is confluent, an indentation is left at both the 

 upper and lower ends ; and the surrounding coloured zones are 

 likewise indented. A single ocellus is thus formed on each tail- 

 covert, though still plainly betraying its double origin. These 

 confluent ocelli differ from the single ocelli of the peacock in 

 having an indentation at both ends, instead of only at the lower 

 or basal end. The explanation, however, of this difference is 

 not difficult; in some species of Polyplectron the two oval 

 ocelli on the same feather stand parallel to each other ; in other 

 species (as in P. chinquis) they converge towards one end; now 

 the partial confluence of two convergent ocelli would manifestly 

 leave a much deeper indentation at the divergent than at the 

 convergent end. It is also manifest that if the convergence were 



