ing only two
little "splint" bones to mark the place where these side hoofs belong.
Thus, step by step, our horses' feet were built up; while these parts
were changing, the other parts of the animals were also slowly
altering. They were at first smaller than our horses,--some of them
not as large as an ordinary Newfoundland dog; others as small as
foxes.

[Illustration: FIG. 11. DEVELOPMENT OF HORSES'S FOOT.]

As if to remind us of his old shape, our horses now and then, but
rarely, have, in place of the little splint bones above the hoof, two
smaller hoofs, just like the foot of _Miohippus_. Sometimes these are
about the size of a silver dollar, on the part that receives the shoe
when horses are shod.

In this way, by slow-made changes, the early mammals pass into the
higher. Out of one original part are made limbs as different as the
feet of the horse, the wing of a bat, the paddle of a whale, and the
hand of man. So with all the parts of the body the forms change to
meet the different uses to which they are put.

At the end of this long promise, which was written in the very first
animals, comes man himself, in form closely akin to the lower animals,
but in mind immeasurably apart from them. We can find every part of
man's body in a little different shape in the monkeys, but his mind is
of a very different quality. While his lower kindred cannot be made to
advance in intelligence any more than man himself can grow a horse's
foot or a bat's wing, he is constantly going higher and higher in his
mental and moral growth.

So far we have found but few traces of man that lead us to suppose
that he has been for a long geological time on the earth, yet there is
good evidence that he has been here for a hundred thousand years or
more. It seems pretty clear that he has changed little in his body in
all these thousands of generations. The earliest remains show us a
large-brained creature, who used tools and probably had already made a
servant of fire, which so admirably aids him in his work.

Besides the development of this wonderful series of animals, that we
may call in a certain way our kindred, there have been several other
remarkable advances in this Tertiary time, this age of crowning
wonders in the earth's history. The birds have gone forward very
rapidly; it is likely that there were no songsters at the first part
of this period, but these singing birds have developed very rapidly in
later times. Among the insec