short distance what is in front of them.
Moreover, forced to supply the lack of ability to see and recognize
what is in front of their head, and which might injure them, they
need only to feel such objects with the aid of their tongue, which
they are obliged to dart out with all their power. This habit has
not only contributed to render the tongue slender, very long and
retractile, but has also led in a great number of species to its
division, so as to enable them to feel several objects at once; it
has likewise allowed them to form an opening at the end of their
head, to enable the tongue to dart out without their being obliged
to open their jaws.

"Nothing is more remarkable than the result of habits in the
herbivorous mammals.

"The quadruped to whom circumstances and the wants which they have
created have given for a long period, as also to others of its race,
the habit of browsing on grass, only walks on the ground, and is
obliged to rest there on its four feet the greater part of its life,
moving about very little, or only to a moderate extent. The
considerable time which this sort of creature is obliged to spend
each day to fill itself with the only kind of food which it
requires, leads it to move about very little, so that it uses its
legs only to stand on the ground, to walk, or run, and they never
serve to seize hold of or to climb trees.

"From this habit of daily consuming great amounts of food which
distend the organs which receive it, and of only moving about to a
limited extent, it has resulted that the bodies of these animals are
thick, clumsy, and massive, and have acquired a very great volume,
as we see in elephants, rhinoceroses, oxen, buffaloes, horses, etc.

"The habit of standing upright on their four feet during the greater
part of the day to browse has given origin to a thick hoof which
envelops the extremity of the digits of their feet; and as their
toes are not trained to make any movement, and because they have
served no other use than as supports, as also the rest of the leg,
the most of them are short, are reduced in size, and even have ended
by totally disappearing. Thus in the _pachyderms_, some have five
toes enveloped in horn, and consequently their foot is divided into
five parts; others have only four, and still others only three. But
in the _ruminants_, which seem to be the most ancient of mammals,
which