THE FAUNA OF BRITAIN. 1 19 



Islands, these were joined in the north to Scandinavia 

 and in the south to Belgium and France. The various 

 phases of geographical evolution of Europe will be 

 studied in the subsequent chapters, and maps will 

 then be given to show as far as possible in a 

 general way the leading characteristics of these 

 great changes. 



I have now given some reasons for the belief that 

 several different migrations of animals entered the 

 British Islands in later Tertiary times. I have also 

 shown why some of them must be looked upon as 

 being older than others, and in so far we have come 

 to a decision as to their relative ages. It still remains 

 for us, however, to examine how their geological ages 

 can be approximately determined. We require for 

 this purpose palasontological aid. 



In the fifth chapter will be found the history of 

 the Siberian migration. And since we possess most 

 valuable records of it in the numerous fossil remains 

 discovered in Central and Western Europe, we are 

 able to trace their progress from the east to the 

 west in a very complete and satisfactory manner. In 

 England their first appearance dates from the Forest- 

 Bed, for here we find remains of the Glutton (Gulo 

 luscus\ Musk-Ox (Ovibos moschatus\ and others (see 

 p. 204). It seems reasonable to suppose, therefore, 

 that the first entry of these Siberian mammals into 

 Europe took place at or just before the Forest-Bed 

 period. But Professor Nehring tells us in his remark- 

 able work on the Tundra and Steppes (p. 222), that in 



