WILD HORSES 159

are the descendants of an old family once distributed
nearly all over the world, but now restricted to four
species in America, south of Mexico, and one in
Malaysia, a species having become extinct in China
during comparatively recent times. The Malayan tapir
has a white back; all the rest are black when fully
grown, but striped white and yellow in early youth.
They all live in swamps and along the forest-clad
river banks, and swim and dive, and are as much at
home in the water as on land.

The horses now walk on their middle fingers and
toes, all that is left of the third and fourth digits
being represented by the splint bones; but their
ancestors have been discovered, in which, going farther
and farther into the past, the changes of the foot can
be traced right back to the five-fingered form with
which all the ungulates started. With the horses,
the asses and the zebras are included, all of
them being assigned to the genus Eguus. The horse
itself, Eguas caballus, is like the camel in having so
remote a history as a domesticated animal that it is
almost impossible to prove that any really wild races
exist. At the same time there are so-called wild
horses, just as there are so-called wild camels; and
the variety with the best claim to the honour would
seem to be the tarpan of Central Asia, which some
consider to be the direct descendants of the old wild
horses of Europe from which neolithic man secured
the first specimens for domestication ; but Prejevalski,
who discovered the wild camels of Central Asia, also
discovered a hitherto unknown kind of horse which
has been assigned by some people to a species of its