opinion of some, it does not reach much beyond the western boundary
of Iowa.

Nor can it be supposed that the driftless regions of Siberia,
Northwestern America, and the Pacific coast are due to the absence of
ice upon them during the Glacial

[1. "Report of the Geological Survey of Wisconsin," vol. i, p. 114.

2. "The Great Ice Age," p. 465.

3. Whitney, "Proceedings of the California Academy of Natural
Sciences."]

{p. 32}

age, for in Siberia the remains of the great mammalia, the mammoth,
the woolly rhinoceros, the bison, and the horse, are found to this
day imbedded in great masses of ice, which, as we shall see, are
supposed to have been formed around them at the very coming of the
Drift age.

But there is another difficulty:

Let us suppose that on all the continents an ice-belt came down from
the north and south poles to 35° or 40° of latitude, and there stood,
massive and terrible, like the ice-sheet of Greenland, frowning over
the remnant of the world, and giving out continually fogs,
snow-storms, and tempests; what, under such circumstances, must have
been the climatic conditions of the narrow belt of land which these