bisons alone are left, and as the American animal has short, incurved
horns, set low down on the skull and far apart at the base;
premaxillaries falling short of the nasals; the last cervical and the
anterior dorsal vertebrae with spines; fourteen pairs of ribs, and a
mane covering the shoulders, we conclude that it is a bison, and as the
same characteristics with minor variations are shown by the European
species, often, but wrongly, called "aurochs," we say that these two
alone of existing _Bovidae_ are bisons, with the yak as a somewhat
questionable relative.

In all essential respects the two bisons are very similar, but minute
comparison shows that the European species, _Bison bonasus_, has a
wider and flatter forehead, bearing longer and more slender horns, and
all the other distinctive features are less pronounced. In the American
species, _Bison bison_, the pelvis is less elevated, producing the
characteristic slope of the hindquarters. It is a coincidence that the
two regions originally inhabited by the bisons are those in which the
white races of men have to the greatest extent thrown their restless
energies into the struggle for existence, with the result that
extinction to nearly the same degree has overtaken these two near
cousins among oxen. A few wild members of the European species still
exist in the Caucasus, as a few of the American are left in British
America, but elsewhere both exist only under protection.

The carefully kept statistics of the Bielowitza herd in Grodno, western
Russia, which includes nearly all but the few wild ones, shows that
between 1833 and 1857 they increased in number from 768 to 1,898, but
from this maximum the decrease has been constant, with trifling halts,
until in 1892 less than five hundred were left; so that even if the
Peace River bison are counted with the remnant of the American species,