from the mountains of Asia Minor and North Africa.<25>
In America we meet with traces of glaciers on a vast scale;
but we can not pause to describe them here.<26>

It need not surprise us, therefore, to learn of reindeer and
musk-sheep feeding on stunted herbage in what now constitutes
Southern France. When a continuous mantle of snow and ice
cloaked all Northern Europe, it is not at all surprising to find
evidence of an extremely cold climate prevailing throughout its
southern borders. We thus see how one piece of evidence fits
into another, and therefore we may, with some confidence,
endeavor to find proofs of more genial conditions when the snow
and ice disappeared, and a more luxuriant vegetation possessed
the land, and animals accustomed to warm and even tropical
countries roamed over a large extent of European territory.
In Switzerland it was long ago pointed out that after the
ancient glaciers had for a long time occupied the low grounds of
that country they, for some cause, retreated to the mountain
valleys, and allowed streams and rivers to work over the
debris left behind them. At Wetzikon most interesting
conclusions have been drawn. We there learn that, after the
retreat of the glaciers, a lake occupied the place, which in
course of time became filled with peat, and that subsequently
the peat was transformed into lignite. To judge from the remains
of animals and plants, the climate must have been at least as
warm as that at present; and this condition of things must have
prevailed over a period of some thousands of years to explain
the thick deposits of peat, from which originated the
lignites.<27>