PHYSICAL CONDITIONS— PLEISTOCENE. 349 



now covered by the North Sea to fall into the Northern Ocean. 

 The western coasts of Europe advanced for many miles into 

 the Atlantic. The Seine with its English tributaries poured 

 through what is now the Channel, to meet the ocean at a point 

 probably not less than 100 miles beyond Ouessant Island. 

 From Argyle in Scotland there extended a deep freshwater 

 lake which passed south into the basin of the Irish Sea, and 

 sent its surplus water in a broad stream through the hollow of 

 St. George's Channel, then a valley in that wide expanse of 

 low crround which stretched south-east from the south of Ireland 

 to the borders of the Erench Landes. With such conditions 

 obtaining in the North Sea and Western Europe, it is likely 

 that the Baltic existed as a freshwater lake. In the Mediter- 

 ranean region the contrast between the past and the present 

 was not less striking. A bridge of land connected Italy 

 and Malta through Sicily to the coasts of Tunis, and Spain in 

 like manner was joined to Barbary. Corsica and Sardinia, 

 united to Italy, formed a peninsula ; and the Balearic Isles 

 similarly would seem to have constituted a portion of the 

 Spanish mainland. Dry land extended over the greater part of 

 the Adriatic and the Grecian archipelago ; in a word, the shores 

 of the Mediterranean generally extended farther out to sea than 

 now. 



Such were the geographical conditions of Europe when the 

 southern mammals — the hippopotamus, the elephant, the rhino- 

 ceros, and their associates — advanced northward to commingle 

 with the denizens of temperate latitudes. Elephants and rhino- 

 ceroses roamed over the same feeding-grounds as Irish deer, oxen, 

 horses, and bisons ; hippopotamuses frequented the rivers that 

 flowed through lands where these and other animals of southern 

 and temperate habitats abounded. Southern and temperate 

 forms, in fact, ranged together from the Mediterranean region up 

 to the north of England ; the mammoth, the horse, the Irish 

 deer, and probably many others, lived in Scotland. Many carni- 

 vores, at the same time, occupied the forests that covered the 

 land, and preyed upon temperate and southern animals alike. 



