ompanied
by the elephant, hippopotamus, and hyaena. Here the migration of all
these species towards the south is arrested by the ocean; but if the
continent had been prolonged still farther, and the land had been of
moderate elevation, it is very probable that they might have extended
their range to a greater distance from the tropics.

Now, if the Indian tiger can range in our own times to the southern
borders of Siberia, or skirt the snows of the Himalaya, and if the puma
can reach the fifty-third degree of latitude in South America, we may
easily understand how large species of the same _genera_ may once have
inhabited our temperate climates. The mammoth (_E. primigenius_),
already alluded to, as occurring fossil in England, was decidedly
different from the two existing species of elephants, one of which is
limited to Asia, south of the 31 degrees of N. lat., the other to
Africa, where it extends, as before stated, as far south as the Cape of
Good Hope. The bones of the great fossil species are very widely spread
over Europe and North America; but are nowhere in such profusion as in
Siberia, particularly near the shores of the Frozen Ocean. Are we, then,
to conclude that this animal preferred a polar climate? If so, it may
well be asked, by what food was it sustained, and why does it not still
survive near the arctic circle?[138]

Pallas and other writers describe the bones of the mammoth as abounding
throughout all the Lowlands of Siberia, stretching in a direction west
and east, from the borders of Europe to the extreme point nearest
America, and south and north, from the base of the mountains of Central
Asia to the shores of the Arctic Sea. (See map, fig. 1.) Within this
space, scarcely inferior in area to the whole of Europe, fossil ivory
has been collected almost everywhere, on the banks of the Irtish, Obi,
Yenesei, Lena, and other rivers. The elephantine remains do not occur in
the marshes and low plains, but where the banks of the rivers present
lofty precipices of sand and clay, from which circumstance Pallas very
justly inferred that, if sections could be obtained, similar bones might
be found in all the elevated lands intervening between the great rivers.
Strahlenberg, indeed, had stated, before the time of Pallas, that
wherever any of the great rivers overflowed and cut out fresh channels
during floods, more fossil remains of the same kind were invariably
disclosed.

[Illustration: MAP OF SIBERIA.

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