76 THK MAMMALIA. 



the glaciers themselves lay there are absolutely 

 no remains of animals, but remains are found in 

 those localities where the edges of the former 

 glaciers must have been situated. And all of these 

 remains belong to an Arctic Alpine fauna, such as 

 now live round about the North Pole the reindeer, 

 musk ox, arctic hare, lemming, arctic fox, arctic 

 hen, arctic owl. The occurrence of all these animals 

 is carefully pointed out by Nehring, for instance, 

 at Tiede in Brunswick, and at Wester egeln. The 

 nature of the bones, and the discovery of young 

 specimens by the side of the older animals, shows 

 that the conclusion must be that the animals lived 

 there. It is still uncertain whether there was only 

 one, or two, or even several ice periods. The 

 Glacial period with its fauna was followed by one 

 with an improved climate, which, however, did not 

 t permit the growth of forests. A new fauna 

 appears corresponding with that of the steppes of 

 South-western Siberia jerboa, suslik, lagomys, 

 sai^a-antelopes. Gaudry, too, has shown that the 

 latter wore also very widely distributed in France. 

 If Northern Europe had only one Glacial age, then 

 the period of the steppe fauna marks the retreat of 

 the glaciers in the very different configuration of 

 the land. If, however, there were two Glacial 

 periods as seems very probable at least in the case 



