in a more pronounced degree; but
these ears have been chosen as models because they present both
characters in conjunction. The upper row of figures likewise shows the
close similarity of hair-tracts, and the direction of growth on the part
of the hair itself, in cases where the human ear happens to be of an
abnormally hirsute character. But this particular instance (which I do
not think has been previously noticed) introduces us to the subject of
hair, and hair-growth, in general.

[Illustration: FIG. 22.--Vestigial characters of human ears. Drawn
from nature.]

(8) _Hair._--Adult man presents rudimentary hair over most parts of the
body. Wallace has sought to draw a refined distinction between this
vestigial coating and the useful coating of quadrumanous animals, in the
absence of the former from the human back. But even this refined
distinction does not hold. On the one hand, the comparatively hairless
chimpanzee which died last year in the Zoological Gardens (_T. calvus_)
was remarkably denuded over the back; and, on the other hand, men who
present a considerable development of hair over the rest of their bodies
present it also on their backs and shoulders. Again, in all men the
rudimentary hair on the upper and lower arm is directed towards the
elbow--a peculiarity which occurs nowhere else in the animal kingdom,
with the exception of the anthropoid apes and a few American monkeys,
where it presumably has to do with arboreal habits. For, when sitting in
trees, the orang, as observed by Mr. Wallace, places its hands above its
head with its elbows pointing downwards: the disposition of hair on
the arms and fore-arms then has the effect of thatch in turning the
rain. Again, I find that in all species of apes, monkeys, and baboons
which I have examined (and they have been numerous), the hair on the
backs of the hands and feet is continued as far as the first row of
phalanges; but becomes scanty, or disappears altogether, on the second
row; while it is invariably absent on the terminal row. I also find that
the same peculiarity occurs in man. We all have rudimentary hair on the
first row of phalanges, both of hands and feet: when present at all, it
is more scanty on the second row; and in no case have I been able to
find any on the terminal row. In all cases these peculiarities are
congenital, and the total absence or partial presence of hair on the
second phalanges is constant in different species of Quadruman