we can find no
obvious use, in the particular animal economy in which they are found,
and yet which are there.

Such are the splint-like bones in the leg of the horse, which I here
show you, and which correspond with bones which belong to certain toes
and fingers in the human hand and foot. In the horse you see they are
quite rudimentary, and bear neither toes nor fingers; so that the horse
has only one "finger" in his fore-foot and one "toe" in his hind foot.
But it is a very curious thing that the animals closely allied to the
horse show more toes than he; as the rhinoceros, for instance: he has
these extra toes well formed, and anatomical facts show very clearly
that he is very closely related to the horse indeed. So we may say that
animals, in an anatomical sense nearly related to the horse, have those
parts which are rudimentary in him, fully developed.

Again, the sheep and the cow have no cutting-teeth, but only a hard
pad in the upper jaw. That is the common characteristic of ruminants in
general. But the calf has in its upper jaw some rudiments of teeth which
never are developed, and never play the part of teeth at all. Well, if
you go back in time, you find some of the older, now extinct, allies of
the ruminants have well-developed teeth in their upper jaws; and at
the present day the pig (which is in structure closely connected with
ruminants) has well-developed teeth in its upper jaw; so that here
is another instance of organs well-developed and very useful, in one
animal, represented by rudimentary organs, for which we can discover
no purpose whatsoever, in another closely allied animal. The whalebone
whale, again, has horny "whalebone" plates in its mouth, and no teeth;
but the young foetal whale, before it is born, has teeth in its jaws;
they, however, are never used, and they never come to anything.
But other members of the group to which the whale belongs have
well-developed teeth in both jaws.

Upon any hypothesis of special creation, facts of this kind appear to me
to be entirely unaccountable and inexplicable, but they cease to be so
if you accept Mr. Darwin's hypothesis, and see reason for believing that
the whalebone whale and the whale with teeth in its mouth both sprang
from a whale that had teeth, and that the teeth of the foetal whale are
merely remnants--recollections, if we may so say--of the extinct whale.
So in the case of the horse and the rhinoceros: suppose that both have
descended by