in the
miocene contemporary with the mastodon.

At the close of the Tertiary period, from causes not yet determined, the
Northern Hemisphere underwent a great depression of temperature. From
a torrid it passed to a glacial condition. After a period of prodigious
length, the temperature again rose, and the glaciers that had so
extensively covered the surface receded. Once more there was a decline
in the heat, and the glaciers again advanced, but this time not so far
as formerly. This ushered in the Quaternary period, during which very
slowly the temperature came to its present degree. The water deposits
that were being made required thousands of centuries for their
completion. At the beginning of the Quaternary period there were
alive the cave-bear, the cave-lion, the amphibious hippopotamus, the
rhinoceros with chambered nostrils, the mammoth. In fact, the mammoth
swarmed. He delighted in a boreal climate. By degrees the reindeer, the
horse, the ox, the bison, multiplied, and disputed with him his food.
Partly for this reason, and partly because of the increasing heat, he
became extinct. From middle Europe, also, the reindeer retired. His
departure marks the end of the Quaternary period.

Since the advent of man on the earth, we have, therefore, to deal with
periods of incalculable length. Vast changes in the climate and fauna
were produced by the slow operation of causes such as are in action at
the present day. Figures cannot enable us to appreciate these enormous
lapses of time.

It seems to be satisfactorily established, that a race allied to the
Basques may be traced back to the Neolithic age. At that time the
British Islands were undergoing a change of level, like that at present
occurring in the Scandinavian Peninsula. Scotland was rising, England
was sinking. In the Pleistocene age there existed in Central Europe a
rude race of hunters and fishers closely allied to the Esquimaux.

In the old glacial drift of Scotland the relics of man are found along
with those of the fossil elephant. This carries us back to that time
above referred to, when a large portion of Europe was covered with ice,
which had edged down from the polar regions to southerly latitudes, and,
as glaciers, descended from the summits of the mountain-chains into the
plains. Countless species of animals perished in this cataclysm of ice
and snow, but man survived.

In his primitive savage condition, living for the most part on fruits,
roots,