most perfect ball-and-socket ocelli a slight difference in the tints,
though not in the shading, between the upper and lower parts of the
ball can be perceived, as before noticed; and the line of separation is
oblique, in the same direction as the bright coloured shades of the
elliptic ornaments. Thus almost every minute detail in the shape and
colouring of the ball-and-socket ocelli can be shewn to follow from
gradual changes in the elliptic ornaments; and the development of the
latter can be traced by equally small steps from the union of two
almost simple spots, the lower one (Fig. 58) having some dull fulvous
shading on its upper side.
[Fig. 61. Portion near summit of one of the secondary wing-feathers,
bearing perfect ball-and-socket ocelli. a. Ornamented upper part. b.
Uppermost, imperfect ball-and-socket ocellus. (The shading above the
white mark on the summit of the ocellus is here a little too dark.) c.
Perfect ocellus.]
The extremities of the longer secondary feathers which bear the perfect
ball-and-socket ocelli, are peculiarly ornamented (Fig. 61). The
oblique longitudinal stripes suddenly cease upwards and become
confused; and above this limit the whole upper end of the feather (a)
is covered with white dots, surrounded by little black rings, standing
on a dark ground. The oblique stripe belonging to the uppermost ocellus
(b) is barely represented by a very short irregular black mark with the
usual, curved, transverse base. As this stripe is thus abruptly cut
off, we can perhaps understand from what has gone before, how it is
that the upper thickened part of the ring is here absent; for, as
before stated, this thickened part apparently stands in some relation
with a broken prolongation from the next higher spot. From the absence
of the upper and thickened part of the ring, the uppermost ocellus,
though perfect in all other respects, appears as if its top had been
obliquely sliced off. It would, I think, perplex any one, who believes
that the plumage of the Argus pheasant was created as we now see it, to
account for the imperfect condition of the uppermost ocellus. I should
add that on the secondary wing-feather farthest from the body all the
ocelli are smaller and less perfect than on the other feathers, and
have the upper part of the ring deficient, as in the case just
mentioned. The imperfection here seems to be connected with the fact
that the spots on this feather shew less tendency than usual to become
confluent into stripes; they are, on the contrary, often broken up into
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