THE: ICE; AGE 
and other wild creatures, whose skeletons, buried in the 
earth, still remain and reveal many facts concerning the 
climatic and other conditions which prevailed in those 
days. 
Again, while the glacial stages were drawing on or dis- 
appearing, the nearness of the ice fields set up atmospheric 
effects of the most far-reaching sort, such as the winds 
known as anticyclones. These blew over the adjoining 
ice-free areas, carrying vast clouds of dust composed 
largely of the finer material from the moraines. The fact 
that this dust settled equally on the tops of the hills as 
well as down in the valleys shows that it was carried there 
by the wind and not by the action of water. As the 
process went on, the dust accumulated in thick beds of a 
special kind of soil known as loess, which occurs in many 
parts of the world, in both the Eastern and the Western 
Hemispheres. Loess is no longer being formed in Europe, 
but it 1s in northern China, where it covers vast areas 
with a mantle many feet in thickness (Plate 19). There 
the people hollow their dwellings out of it, and the roads 
in time become worn down so deep that not only they 
but even the vehicles passing along them are often quite 
invisible from the surface. 
Along with the formation of the loess, the aspect of 
the country gradually assumed a steppe condition, like 
the seemingly limitless plains of southern Russia and 
central Asia. These have an extreme range of temper- 
ature, with short hot summers, when they are covered 
with grass and shrubs, and long bitterly cold winters, 
when the snow lies deep, blizzards rage, and animals 
perish by the thousands. 
To the latter peculiarity of a “‘steppe’’ phase of climate 
we owe much of our knowledge about the animal life of 
the time, including such plains-loving forms as the bison 
and the horse. For the blizzards killed many creatures 
whose bones, left after the snow melted away in spring, 
were buried by the dust storms of the following summer. 
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