of elephant prefers, will not enable us to determine, or even to
offer a probable conjecture, concerning that of the extinct species. No
one acquainted with the gramineous character of the food of our
fallow-deer, stag, or roe, would have assigned a lichen to the
reindeer."

Travellers mention that, even now, when the climate of eastern Asia is
so much colder than the same parallels of latitude farther west, there
are woods not only of fir, but of birch, poplar, and alder, on the banks
of the Lena, as far north as latitude 60 degrees.

It has, moreover, been suggested, that as, in our own times, the
northern animals migrate, so the Siberian elephant and rhinoceros may
have wandered towards the north in summer. The musk oxen annually desert
their winter quarters in the south, and cross the sea upon the ice, to
graze for four months, from May to September, on the rich pasturage of
Melville Island, in lat. 75 degrees. The mammoths, without passing so far
beyond the arctic circle, may nevertheless have made excursions, during
the heat of a brief northern summer, from the central or temperate parts
of Asia to the sixtieth parallel of latitude.

Now, in this case, the preservation of their bones, or even occasionally
of their entire carcasses, in ice or frozen soil, may be accounted for,
without resorting to speculations concerning sudden revolutions in the
former state and climate of the earth's surface. We are entitled to
assume, that, in the time of the extinct elephant and rhinoceros, the
Lowland of Siberia was less extensive towards the north than now; for we
have seen (p. 80) that the strata of this Lowland, in which the fossil
bones lie buried, were originally deposited beneath the sea; and we
know, from the facts brought to light in Wrangle's Voyage, in the years
1821, 1822, and 1823, that a slow upheaval of the land along the borders
of the Icy Sea is now constantly taking place, similar to that
experienced in part of Sweden. In the same manner, then, as the shores
of the Gulf of Bothnia are extended, not only by the influx of sediment
brought down by rivers, but also by the elevation and consequent drying
up of the bed of the sea, so a like combination of causes may, in modern
times, have been extending the low tract of land where marine shells
and fossil bones occur in Siberia.[149] Such a change in the physical
geography of that region, implying a constant augmentation in the
quantity of arctic land, would, acco