SCOTLAND AS MAN FOUND IT 13 



fauna form no permanent stations ; for they pass over such an 

 area in waves, forsaking it on a northwards trek as the cold 

 retreats, as easily as they entered it from the southward with 

 the Arctic conditions. But Britain stands in a different case 

 from such continental areas. Scarcely had the last of the 

 immigrant contingents crossed from the main mass of their 

 fellows on the continent, than the gradual sinking of the land 

 relative to the sea led to the submergence of the valleys of 

 the North Sea and of the English Channel, so that, as a 

 twelfth century troubadour quaintly sings of the latter, 



That famous stretch of fertile land 



Is hidden now by sea and sand, 



No more will its venison grace the dish, 



The ancient forest yields nought but fish. 



So the immigrants to Britain were cut off from access to the 

 continent of Europe. The result of this isolation is plainly 

 to be seen in the strange assemblage of animals which 

 greeted man on his arrival in Scotland. The Arctic creatures, 

 the beasts of the plains, and the forest lovers, each ranging 

 northwards as the conditions which had attracted them 

 ebbed towards the north, were checked in their migration 

 by the sea-walls of northern Britain, and as a consequence 

 were compelled to make the best of the changes of climate 

 and vegetation which overtook them. Some, unable to adapt 

 themselves to unusual climes, had died out before the coming 

 of man, but representatives of each group remained to in- 

 dicate the successive changes of Scottish conditions in the 

 days before man. 



It is not to be expected that the peat-bogs and other 

 deposits should furnish a complete synopsis of the fauna, 

 partly because the bones of the smaller animals are more 

 liable to disappear through the ordinary processes of decay, 

 and partly because the deposits have only in a very few 

 cases been systematically examined with the investigation 

 of their animal content in view; so that we have to be satisfied 

 with identifications of the remains which have appealed most 

 to the utilitarian excavators of peat and marl, usually the 

 bones of the larger animals. Even so we can furnish a fair 

 view of the general aspect of the animal life. 



Imagine that from our fourteen million acres of culti- 

 vated land and mountain grazings the domestic stock had 



