The Descent of Man

projection in the same situation. So, again, there
can hardly be a doubt that the little point (a) on
the head of the female Onitis furcifer, as well as
on the head of the females of two or three allied
species, is a rudimentary representative of the
cephalic horn, which is common to the males of
so many Lamellicorn beetles, as in Phanaeus
(Fig. 18).
The old belief that rudiments have been created
to complete the scheme of nature is here so far
from holding good, that we have a complete
inversion of the ordinary state of things in the
family. We may reasonably suspect that the
males originally bore horns and transferred
them to the females in a rudimentary condition,
as in so many other Lamellicorns. Why the males
subsequently lost their horns, we know not;
but this may have been caused through the
principle of compensation, owing to the development
of the large horns and projections on
the lower surface; and as these are confined to