o attempt
to unravel these successive changes and migrations. Great numbers of
species were destroyed, and at length, when the climatic condition
of the earth reached a state of comparative stability, the surviving
animals settled in the geographical regions in which we find them
to-day.

The only question into which we may enter with any fullness is that
of the relation of human development to this grave perturbation of the
condition of the globe. The problem is sometimes wrongly conceived. The
chief point to be determined is not whether man did or did not precede
the Ice-Age. As it is the general belief that he was evolved in the
Tertiary, it is clear that he existed in some part of the earth before
the Ice-Age. Whether he had already penetrated as far north as Britain
and Belgium is an interesting point, but not one of great importance.
We may, therefore, refrain from discussing at any length those disputed
crude stone implements (Eoliths) which, in the opinion of many, prove
his presence in northern regions before the close of the Tertiary.
We may also now disregard the remains of the Java Ape-Man. There are
authorities, such as Deniker, who hold that even the latest research
shows these remains to be Pliocene, but it is disputed. The Java race
may be a surviving remnant of an earlier phase of human evolution.

The most interesting subject for inquiry is the fortune of our human and
prehuman forerunners during the Pliocene and Pleistocene periods. It may
seem that if we set aside the disputable evidence of the Eoliths and the
Java remains we can say nothing whatever on this subject. In reality a
fact of very great interest can be established. It can be shown that
the progress made during this enormous lapse of time--at least a million
years--was remarkably slow. Instead of supposing that some extraordinary
evolution took place in that conveniently obscure past, to which we can
find no parallel within known times, it is precisely the reverse.
The advance that has taken place within the historical period is far
greater, comparatively to the span of time, than that which took place
in the past.

To make this interesting fact clearer we must attempt to measure the
progress made in the Pliocene and Pleistocene. We may assume that the
precursor of man had arrived at the anthropoid-ape level by the middle
of the Miocene period. He is not at all likely to have been behind
the anthropoid apes, and we saw that they were we