to-day are better
fitted to be the help-meets of man than were their ancestors of an
earlier time, we may note the state of the horse at the time when that
genus was undergoing its development in the region about the upper
waters of the Missouri. As may be imagined, the long and difficult
passage from the five-toed to the single-toed form was slowly
accomplished, and to its doing went a great many temporary forms, which
served, we may say, as stepping-stones for the ongoing. So far as we can
judge, these intermediate forms were small, rather frail creatures,
which probably could not have been made to serve any purpose useful to
man. It was not until the mechanical system of the large single toe with
the wonderfully developed nail, which makes up the foot and hoof of the
horse, had been attained, that the creature becomes fit for the
wonderful work we have persuaded him to do in our civilization.

A comparison of the skulls of the Tertiary mammals and those of our own
day indicates that in certain of the important series, and presumably in
them all, the brain has increased in size from the earlier to the later
times. This increase in brain capacity has doubtless been attended by a
decided gain in the measure of intelligence, a gain which has doubtless
served to make the modern representatives of the series fitter for man's
use than their ancestors were. For, while the number of our very useful
domesticated forms may seem at first sight to be dull of wit, none of
them are really low in the intellectual scale as we apply it to the
brute; in fact, a considerable measure of intelligence is absolutely
required as a condition for true subjugation. This is seen by the fact
that nothing like a real adoption into our social system has ever been
accomplished except with a few of the higher orders of mammals and
birds, species which have an intellectual capacity that we recognize as
akin to our own. Thus, so far as we can see, man's appearance on this
stage was, so far as it relates to the possibility of companionship with
the lower life, exceedingly well timed. He came at a period when the
life was ready to give him and to receive from him a large measure of
help. If his advent had been much earlier, he might have had less
trouble in his contests with the larger carnivora; but if there had been
a lack of beasts to obey his will, it is doubtful whether he could
himself have won his way above that primitive life.

DOMESTICATE