302 THE STORY OF THE EAKTH AND MAN. 



which perhaps inhabited chiefly the swamps along 

 the large rivers running through areas now under 

 the sea. The occurrence of such an animal shows 

 an abundant vegetation, and a climate so mild, that 

 the rivers were not covered with heavy ice in winter ; 

 for the supposition that this old hippopotamus was 

 a migratory animal seems very unlikely. Another 

 animal of this time, was the magnificent deer, known 

 as the Irish elk; and which perhaps had its prin- 

 cipal abode on the great plain which is now the Irish 

 Sea. The terrible machairodus, or cymetar-toothed 

 tiger, was continued from the Pliocene ; and in addition 

 to species of bear still living, there was a species of 

 gigantic size, probably now extinct, the cave bear. 

 Evidences are accumulating, to show that all or nearly 

 all these survived until the human period. 



If we turn now to those animals which are only 

 locally extinct, we meet with some strange, and at 

 first sight puzzling anomalies. Some of these are 

 creatures now limited to climates much colder than 

 that of Britain. Others now belong to warmer cli- 

 mates. Conspicuous among the former are the musk- 

 sheep, the elk, the reindeer, the glutton, and the 

 lemming. Among the latter, we see the panther, 

 the lion, and the Cape hyena. That animals now so 

 widely separated as the musk-sheep of Arctic America 

 and the hyena of South Africa, could ever have in- 

 habited the same forests, seems a dream of the wildest 

 fancy. Yet it is not difficult to find a probable solu- 

 tion of the mystery. In North America, at the pre- 



