Page 233 - Lokmanya Tilak Samagra (khand 2)

20 SAMAGRA TlLAK - 2 IIi THE ARCTiC HOME

drifts, belonging to two different periods. Prof. Geikie mentions
four such Glacial periods, with correponding Inter-Glacial
periods, as having occurred in succession in Europe during the
Pleistocene period. But though this opinion is not accepted by
other geologists,· yet the existence of two Glacial epochs, with
an intervening Inter-Glacial period, is now considered as con-
clusively established.
A succession of cold and warm climates must have chara-
cterised these Glacial and Inter-Glacial periods which were also
accompanied by extensive movements of depression and eleva-
tion of land, the depression taking place after the land was
weighed down with the enormous mass of ice. Thus a period
of glaciation was marked by elevation, extreme cold and· the
invasion of the ice-caps over regions of the present Temperate
zone; while an Inter-Glacial period was accompanied by depres-
sion of land and milder and congenial climate which made even
the Arctic regions habitable. The remains of the Palreolithic
man have been found often imbedded between the two boulder-
clays of two different Glacial periods, a fact which conclusively
establishes the existence of man in the Inter-Glacial period in
the Quaternary era. Prof. Geikie speaking of the changes o-
climate in the Glacial and Inter-Glacial period remarks that
•' during the Inter-Glacial period the climate was characterised
by clement winters and cool summers so that the tropical plants
and animals, like elephants, rhinoceroses and hippopotamuses
ranged over the whole of the Arctic region, and in spite of
numerous fierce carnivora, the Palreolithic man had no unplead
sant habitation there. "* It will thus be seen that in point o
climate the Pleistocene period, or the early Quaternary era, was
intermediate between the early geological ages when uniform
genial climate prevailed over the globe, and the modern period
when it is differentiated into zones. It was, so to speak, a transi-
tional period marked by violent changes in the climate, that was
mild and genial in the Inter-Glacial, and severe and inclement
during the Glacial period. It was at the beginning of the Post-
Glacial or the Recent period that moderri climatic conditions
were established. Prof. Geikie is, however, of opinion that even
the beginning of the Post-Glacial period was marked, at least

" Fragments of Earth Lore, p. 266.