Reindeer. 



290 MAN AND THE GLACIAL PERIOD. 



otter, the weasel, the wild-cat, the fox, the wolf, the wild 

 boar, and the brown bear. 



To account for this strange intermingling of arctic and 

 torrid species of animals, especially in Europe, during man's 

 occupancy of the region in glacial times, various theories 

 have been resorted to, but none of them can be said to be 

 altogether satisfactory. One hypothesis is that the bones 



of these diverse animals 

 became mingled by reason 

 of the great range of the 

 annual migration of the 

 species. The reindeer, for 

 example, still performs ex- 

 tensive annual migrations. 

 In summer it ventures far 

 out upon the tundras of 

 North America and Siberia 

 to feed upon the abundant vegetation that springs up like 

 magic under the influence of the long days of sunshine ; 

 while, as winter approaches, it returns to the forests of the 

 interior. Or in other places this animal and his associates, 

 like birds of passage, move northward in summer to escape 

 the heat, and southward in the winter to escape the ex- 

 treme cold. Many of the other animals also are more or 

 less migratory in their habits. 



Thus it is thought that during the Glacial period, when 

 man occupied northern France and southern England, 

 the reindeer, the musk sheep, the arctic fox, and perhaps 

 the hippopotamus and some other animals, annually 

 vibrated between northern England and southern France, 

 a slight elevation of the region furnishing a land passage 

 from England to the continent ; while the chamois and 

 other Alpine species vibrated as regularly between the val- 

 leys in winter and the mountain-heights in summer. The 

 habits of these species are such that it is not difficult to see 

 how in their case this migration could have taken place. 



