the ball an oblique almost pure-white mark, which shades off downwards
into a pale-leaden hue, and this into yellowish and brown tints, which
insensibly become darker and darker towards the lower part of the ball.
It is this shading which gives so admirably the effect of light shining
on a convex surface. If one of the balls be examined, it will be seen
that the lower part is of a brown tint and is indistinctly separated by
a curved oblique line from the upper part, which is yellower and more
leaden; this curved oblique line runs at right angles to the longer
axis of the white patch of light, and indeed of all the shading; but
this difference in colour, which cannot of course be shewn in the
woodcut, does not in the least interfere with the perfect shading of
the ball. It should be particularly observed that each ocellus stands
in obvious connection either with a dark stripe, or with a longitudinal
row of dark spots, for both occur indifferently on the same feather.
Thus in Fig. 57 stripe A runs to ocellus a; B runs to ocellus b; stripe
C is broken in the upper part, and runs down to the next succeeding
ocellus, not represented in the woodcut; D to the next lower one, and
so with the stripes E and F. Lastly, the several ocelli are separated
from each other by a pale surface bearing irregular black marks.
[Fig. 58. Basal part of the secondary wing feather, nearest to the
body.]
I will next describe the other extreme of the series, namely, the first
trace of an ocellus. The short secondary wing-feather (Fig. 58),
nearest to the body, is marked like the other feathers, with oblique,
longitudinal, rather irregular, rows of very dark spots. The basal
spot, or that nearest the shaft, in the five lower rows (excluding the
lowest one) is a little larger than the other spots of the same row,
and a little more elongated in a transverse direction. It differs also
from the other spots by being bordered on its upper side with some dull
fulvous shading. But this spot is not in any way more remarkable than
those on the plumage of many birds, and might easily be overlooked. The
next higher spot does not differ at all from the upper ones in the same
row. The larger basal spots occupy exactly the same relative position
on these feathers as do the perfect ocelli on the longer wing-feathers.
By looking to the next two or three succeeding wing-feathers, an
absolutely insensible gradation can be traced from one of the
last-described basal spots, together with the next higher one in the
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