138 SEXUAL SELECTION : 'bIEDS. Paet IL 
the spring the males, as previously described, strut 
about before the comparatively plain-coloured females,, 
expanding and erecting their tail and wing-feathers, 
which are ornamented with numerous ocelli. I request 
the reader to turn back to the drawing (fig. 51, p. 90) 
of a Polyplectron. In P. Napoleonis the ocelli are 
confined to the tail, and the back is of a rich me- 
tallic blue, in which respects this species approaches 
the Java peacock. P. Hardwickii possesses a pecu- 
liar top-knot, somewhat like that of this same kind 
of peacock. The ocelli on the wings and tail of the 
several species of Polyplectron 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. cliinquis shades into brown which 
is edged with cream-colour, so that the ocellus is 
here surrounded with differently, though not brightly, 
shaded concentric zones. The unusual length of the 
tail-coverts is another highly remarkable character 
in Polyplectron; for in some of the species they are 
half as long, and in others two-thirds of the length 
of the true tail-feathers. The tail-coverts are ocel- 
lated, as in the peacock. Thus the several species 
of Polyplectron manifestly make a graduated ap- 
proach in the length of their tail-coverts, in the zoning 
of the ocelli, and in some other characters, to the 
peacock. 
Notwithstanding this approach, the first species of 
Polyplectron which I happened to examine 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. 54), one on each side of the shaft. Hence I 
