MAN FROM THE FARTHEST PAST 
ill equipped for his struggle with ferocious beasts and a 
bitter climate (Plate 21). 
After the maximum of the fourth glacial stage the 
climate did not at once turn warmer. Instead, there 
followed a period of oscillation, with at least three minor 
returns of the ice, during which the mammoth, the woolly 
rhinoceros, the reindeer, and other cold-weather animals 
continued to live in Europe, although many other crea- 
tures found there during the earlier periods had died out. 
Gradually the slow changes of temperature character- 
izing the Postglacial Period became less and less marked, 
and toward the beginning of the Neolithic or New Stone 
Age, the climate became pretty much what it is today. 
It is interesting to note, in this connection, that the 
Ice Age still exists in the north and south polar regions. 
These, however, were not always covered with ice, as they 
are today. The fossil remains of plants found there prove 
that they have in times past enjoyed a mild and genial 
climate. Perhaps some day they will do so again. On the 
other hand the present may be simply an interglacial 
stage, with another return of the ice sheet awaiting us 
in the far distant future. 
Various attempts have been made to determine how 
long the Ice Age lasted, and definite light has recently 
been thrown on the length of time since the last or Wurm 
glacial stage attained its maximum. So far, however, 
we do not know how long it had taken to reach that 
point; nor how long the preceding periods lasted. Some 
have put the beginning of the Pleistocene period, or Ice 
Age, as far back as 1,000,000 years ago; others at half 
that figure; Penck estimated it at 525,000 years, and 
Sir Arthur Keith at 200,000 years ago. 
Geologists practically agree, however, that the Ice Age 
closed both in North America and in Europe some- 
thing like 10,000 years ago, a little more in the southern 
portions of those continents and a little less further 
north. Thus Scandinavia, lying considerably nearer the 
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