The ocelli on the wing-feathers are wonderful objects; for they are so
shaded that, as the Duke of Argyll remarks (90. The Reign of Law,
1867, p. 203.), they stand out like balls lying loosely within sockets.
When I looked at the specimen in the British Museum, which is mounted
with the wings expanded and trailing downwards, I was however greatly
disappointed, for the ocelli appeared flat, or even concave. But Mr.
Gould soon made the case clear to me, for he held the feathers erect,
in the position in which they would naturally be displayed, and now,
from the light shining on them from above, each ocellus at once
resembled the ornament called a ball and socket. These feathers have
been shown to several artists, and all have expressed their admiration
at the perfect shading. It may well be asked, could such artistically
shaded ornaments have been formed by means of sexual selection? But it
will be convenient to defer giving an answer to this question until we
treat in the next chapter of the principle of gradation.
The foregoing remarks relate to the secondary wing-feathers, but the
primary wing-feathers, which in most gallinaceous birds are uniformly
coloured, are in the Argus pheasant equally wonderful. They are of a
soft brown tint with numerous dark spots, each of which consists of two
or three black dots with a surrounding dark zone. But the chief
ornament is a space parallel to the dark-blue shaft, which in outline
forms a perfect second feather lying within the true feather. This
inner part is coloured of a lighter chestnut, and is thickly dotted
with minute white points. I have shewn this feather to several persons,
and many have admired it even more than the ball and socket feathers,
and have declared that it was more like a work of art than of nature.
Now these feathers are quite hidden on all ordinary occasions, but are
fully displayed, together with the long secondary feathers, when they
are all expanded together so as to form the great fan or shield.
The case of the male Argus pheasant is eminently interesting, because
it affords good evidence that the most refined beauty may serve as a
sexual charm, and for no other purpose. We must conclude that this is
the case, as the secondary and primary wing-feathers are not at all
displayed, and the ball and socket ornaments are not exhibited in full
perfection until the male assumes the attitude of courtship. The Argus
pheasant does not possess brilliant colours, so that his success in
love appears to depend on the great size of his plumes, and on the
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