st none. Dr. Croll thinks
it was caused by the varying inclination of the earth's axis, which
produced the relative position of the two poles toward the sun to be
periodically reversed at distant periods. Dr. James Geikie agrees with
Croll on the reverse of seasons every 10,500 years during certain
periods of high ellipticity of the earth's orbit.

But it may be asked, "How could the fauna and flora propagate
themselves under such conditions?" The flora itself at the quaternary
age was of extreme vigor. We know this from the little which is left
us, but more especially from the presence of a large number of
herbivorous animals--stags, horses, elephants, rhinoceros, etc.--which
animated the plains and valleys of Europe and America at the same
time. Evidently they could not have lived and propagated themselves
without abundant vegetation for nourishment and development.

That which has deceived the adherents of the glacial theory, as
understood in its absolute sense, is, they have generally placed a too
high estimate on its extent and intensity. It needs but a little
effort of the reasoning powers to come to the conclusion that the
earth had cooled to the degree that all animal and vegetable life
could exist upon it, and that a portion of the earth's surface
permanently covered with snow and ice was absolutely indispensable to
the existence, perpetuity, and well-being of animal and vegetable
life. Again, they have attributed to the glaciers the rocks, gravels,
and other material which they have found spread here and there long
distances from the mountains. The transportation of the so-called
erratic rocks has appeared inexplicable in any other way, and the
piles of rock and gravel have been considered so many _moraines_, that
is, deposits of diverse material transported by the glaciers. They do
not regard the probability of other agents taking the place of
glaciers, and undervalue the moving power of water. Water in liquid
state has often produced analogous effects, and it has often been the
error of the glacialists to confound the one with the other. The
erratic rocks and the moraines are undoubtedly the ordinary
indications of the ancient gravels, but, taken isolatedly, they are
not sufficient proof. In order to convince they should be accompanied
with a third indication, which is the presence of striated rocks which
we find in the neighborhood of our actual glaciers. When all these
signs are together then there is ha