EFFECTS OF THE ICE-AGE 181 



sand, left behind by the melting ice. The varied 

 and abundant flora which had spread so far within 

 the Arctic circle was driven away into more southern 

 and less ungenial climes. But most memorable of 

 all was the extirpation of the prominent large animals 

 which, before the advent of the ice, had roamed over 

 Europe. The lions, hyaenas, wild horses, hippopotami 

 and other creatures either became entirely extinct or 

 were driven into the Mediterranean basin and into 

 Africa. In their place came northern forms — the 

 reindeer, glutton, musk ox, woolly rhinoceros, and 

 mammoth. 



Such a marvellous transformation in climate, in 

 scenery, in vegetation, and in inhabitants, within what 

 was after all but a brief portion of geological time, 

 though it may have involved no sudden or violent 

 convulsion, is surely entitled to rank as a catastrophe 

 in the history of the globe. It was possibly brought 

 about mainly if not entirely by the operation of forces 

 external to the earth. No similar calamity having 

 befallen the continents within the time during which 

 man has been recording his experience, the Ice-Age 

 might be cited as a contradiction to the doctrine of 

 uniformity. And yet it manifestly arrived as part of 

 the established order of Nature. Whether or not we 

 grant that other ice-ages preceded the last great one, 

 we must admit that the conditions under which it 

 arose, so far as we know them, might conceivably 

 have occurred before and may occur again. The 

 various agencies called into play by the extensive 

 refrigeration of the northern hemisphere were not 

 different from those with which we are familiar. Snow 



