The Descent of Man

Luschka has recently discovered at the extremity
of the coccygeal bones a very peculiar convoluted
body, which is continuous with the
middle sacral artery; and this discovery led
Krause and Meyer to examine the tail of a
monkey (Macacus), and of a cat, in both of
which they found a similarly convoluted body,
though not at the extremity.
The reproductive system offers various rudimentary
structures; but these differ in one important
respect from the foregoing cases. Here
we are not concerned with the vestige of a part
which does not belong to the species in an efficient
state, but with a part efficient in the one
sex, and represented in the other by a mere
rudiment. Nevertheless, the occurrence of such
rudiments is as difficult to explain, on the belief
of the separate creation of each species, as in
the foregoing cases. Hereafter I shall have to
recur to these rudiments, and shall shew that
their presence generally depends merely on