this species of Polyplectron make a near approach in structure and
ornamentation to the corresponding feathers of the peacock.
As far, then, as gradation throws light on the steps by which the
magnificent train of the peacock has been acquired, hardly anything
more is needed. If we picture to ourselves a progenitor of the peacock
in an almost exactly intermediate condition between the existing
peacock, with his enormously elongated tail-coverts, ornamented with
single ocelli, and an ordinary gallinaceous bird with short
tail-coverts, merely spotted with some colour, we shall see a bird
allied to Polyplectron that is, with tail-coverts, capable of erection
and expansion, ornamented with two partially confluent ocelli, and long
enough almost to conceal the tail-feathers, the latter having already
partially lost their ocelli. The indentation of the central disc and of
the surrounding zones of the ocellus, in both species of peacock,
speaks plainly in favour of this view, and is otherwise inexplicable.
The males of Polyplectron are no doubt beautiful birds, but their
beauty, when viewed from a little distance, cannot be compared 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 preference for the most
beautiful males, rendered the peacock the most splendid of living
birds.
ARGUS PHEASANT.
Another excellent case for investigation 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 loose within sockets, and
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
colouring 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 ball-and-socket effect, seems as
incredible as that one of Raphael s Madonnas should have been formed by
the selection of chance daubs of paint made by a long succession of
young artists, not one of whom intended at first to draw the human
figure. In order to discover how the ocelli have been developed, we
cannot look to a long line of progenitors, nor to many closely-allied
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