areas and both Europe and America, since we know that an
abundant vegetation spread from there, as a center, to both these
countries. But at that epoch circumstances were different. The great
North Temperate lands were in a "comparatively fragmentary and insular
condition."<25> There were great inland seas in both Europe and Asia,
through which powerful currents would have flowed from the Indian Ocean
to Arctic regions.

Somewhat similar conditions prevailed in North America. The western part
was in an insular condition. A great sea extended over this part of the
country, joining the Arctic probably on the north, through which heated
water would pour into the polar sea. And so, instead of a Glacial
Age, we find evidence of a mild and genial climate, with an abundant
vegetation.

We thus see that there are two theories as to the cause of the Glacial
Age presented for our consideration. Both of them have received the
sanction of scholars eminent for their scientific attainments. On
inspection we see they are not antagonistic theories. They may both
be true for that matter, and all would admit that whatever effect they
would produce singly would be greatly enhanced if acting together.
Indeed, there are very good reasons for supposing both must have acted
in unison.

There seem to be very good reasons for not believing that the
eccentricity of the earth's orbit, acting alone, produced the glacial
cold. If that were the case, then whenever the eccentricity was great
we should have a Glacial Age. Now, at some period of time during the
long-extended Tertiary Age we are certain the eccentricity of the
earth's orbit became very great, much more so, in fact, than that which
is supposed to have produced the cold of the Quaternary Age. But we are
equally certain there was no glacial epoch during this age.<26> What
other explanation can we give for its non-appearance except that
geographical conditions were not favorable?

But, on the other hand, there are certain features connected with the
phenomena of the Glacial Age that seem very difficult of explanation,
if we suppose that geographical changes alone produced them. We must
remember that evidences of the former presence of glaciers are found
widely scattered over the earth. We shall, therefore, have to assume an
elevation not only for America and Europe, but extend it over into Asia,
and take in the Lebanon Mountains, for they also show distinct traces
of glaciers. And this