own in mighty billows over northern Europe and America, burying
everything beneath its crushing weight, and bringing many forms of life
to a sudden and untimely end. No doubt a considerable number of species
of animals and plants perished before this frightful invasion. A notable
instance among these was perhaps that of the American horse, which
disappeared at about this period. Other species survived by a retreat to
more tropical regions, to return after the invasion had spent its force.
Still others may have survived by adapting themselves to the changed
conditions, emerging as new species or well-marked varieties.

Among the beings which passed unscathed through this extraordinary
change in climate was apparently man. And it seems safe to affirm that
man's contest with the glacial conditions, whose force was exerted upon
his mind instead of on his body, was one of the most potent influences
in the evolution of the human race. Man entered the contest at a low
level of mental development; he emerged from it at a comparatively high
level.

No one to-day questions that man was an inhabitant of Europe during the
Glacial Age. The proofs of this are too numerous and positive to be
doubted. He may have inhabited America in the same period, though of
this there still remains some doubt. Claims have been made of the
discovery of evidences of man in Europe long before the glacial epoch,
reaching as far back as the Pliocene and even the Miocene Age. But these
claims have not been established beyond question, and the earliest
generally acknowledged traces of man are confined to glacial Europe.

Yet we are forced to acknowledge that if man existed in Europe during
the prevalence of the ice age, he, or his ancestor, must have been there
before that period. It is absolutely certain that no animal accustomed
to tropical conditions would have chosen this period of extreme cold to
migrate from the warm tropics to the frozen north. The fact that man was
in Europe during glacial times is the very strongest evidence that he
reached there during the milder preceding period, when a genial and
uniform climate is believed to have prevailed throughout southern and
central Europe. If we could accept as fact the seeming very ancient
evidences of man's handiwork, we would be obliged to consider him an
inmate of Europe long ages before the glacial epoch.

If, as there is reason to believe, the man of Africa at that remote
period was the ancesto