and enamel enclosed in the investing layer of cement. The bony cores
of the horns are completely honeycombed with a number of large and
irregularly shaped cavities. Skull without any pits or fissures below the
eyes ; the sockets of the eyes generally not prominent ; the premaxilla;
sometimes reaching the nasal bones. Canon-bones short and stout.
The group appears to be one of the most specialised and advanced
of all the ruminants, as is indicated by the structure of the cheek-teeth,
and its comparatively late appearance in time. Their nearest relatives
are not easy to determine. The absence o f horns in the females of some
of the extinct species points to descent from a group in which a similar
condition obtained. On the other hand, their molar teeth are very similar
to those of the oryx and sable antelope group, and unlike those of all
other ruminants. And as this character is not very likely to have
originated independently, a relationship to that group is suggested. Such
a connection is in harmony with the absence of face-glands in the group of
antelopes in question, and the small size o f the vacuities in the skull below'
the eyes. But, it may be urged, in these antelopes horns are developed
in both sexes, and the muzzle is hairy. The latter difference is but of
little importance, as it is quite probable that a naked muzzle is a feature
of comparatively modern acquisition. With regard to the former,iftf there
be any relationship between the two groups, the only explanation would
seem to be that in the ancestral antelopes the females were hornless, and
that the oxen branched off before horns were acquired by that sex.
Distribution.— Nearly all the habitable parts of the globe, with the
exception of the Australasian and Neotropical regions, but represented
in the New World only by the American bison and some nearly allied
fossil forms. In time, dating in India from the Pliocene epoch, and
represented in Europe in the latter portion of that epoch. The numerical
abundance of species, both living and extinct, in the Old World, and
especially Asia, points to the conclusion that the group originated in the
Eastern Hemisphere, and not improbably in Asia. Its immigration into
Africa south of the Sahara was doubtless a comparatively modern event;
this being confirmed by the fact that all its representatives found in that
continent appear to be modifications of a single specific type. Equally
modern and equally limited was doubtless also the migration into America;
the route o f this migration being clearly indicated by the fossil remains
of the bison which occur in Alaska. This emigration may not unlikely
have been contemporaneous with that of the wapiti, which, like the bison,
has never succeeded in penetrating into the southern half of the New
World.
Habits.—In the nature of their habitat oxen display a considerable
amount of variability. Many prefer forest districts, especially where the
ground S s hilly and rocky, but the American bison was mainly an
inhabitant o f the open prairies, and the yak is still a denizen of the bleak
highlands of Tibet. Probably, however, all the members of the group were
originally forest-dwelling animals, some of which have been compelled
by stress of circumstances to take to a life on open plains oE plateaux ; and
the fact that the American bison has a woodland race which is probably
more primitive than its cousin of the prairies, affords a distinct confirmation
of this hypothesis. All, or nearly all the species associate in herds of
larger or smaller size, which may be protected and led by the bulls, and in
some cases may be numbered in thousands; but in many instances, at any
rate, the oldest males separate themselves from the herds to pass a more
or les;s completely solitary existence, and cows take the lead.
Of all ruminants, oxen are perhaps the most generally useful to mankind.
Not only do they provide flesh of a highly nutritive and palatable
nature, but the females furnish milk, and the skins of both sexes afford a
most valuable supply o f leather. The horns and hoofs, too, are largely
used for several purposes ; while the American bison formerly supplied
rugs or robes that afforded one o f the most efficient protections against