INTRODUCTION. xlv 



livintr state in Southern Russia, in the area between the Don and the Volga. An animal of 

 aquatic habits, it is especially abundant on the banks of the Soura River, in latitude 55° 

 north, and longitude 47° east, under a temperate continental climate, cold in winter but 

 hot in summer. Dr. Pallas, in his 'Second Travels,' describes the country which it 

 inhabits, after an unusually severe winter, as covered with tulips, saffron, and the Star of 

 Bethlehem, and although Spermoplnlus citiUus, the Alpine marmot, was in the neighbour- 

 hood, there were vineyards close by. The water-shrew of the Pyrennees, Myogale 

 Pyrennaica, Geoffr., is a closely allied species, differing from the Sorex nwschatus {Myogale 

 moschata, Fischer), in its smaller size, and long and rounded tail. 



An analysis, therefore, of the fifty-three Pleistocene species, those about which there is 

 any doubt being omitted, gives 



14 as extinct. 



8 as confiued to northern climates. 



2 ,, southern climates. 



1 as common to temperate and hot climates. 

 28 as still inhabiting the temperate zones of Europe. 



53 



•^ 11. Inferences as to Pleistocene climate. — The proportion of fourteen extinct to 

 thirty-nine living species proves that, in the geological sense, the present order of things is 

 separated by a small interval from the Pleistocene ; while, from the fact that twenty-eight 

 species, or half, are still living in the same European area, we may infer that the conditions 

 of existence, the climate and food, and the like were then very similar to those now 

 obtaining in the area in which they live. That, however, some great physical change has 

 taken place in Europe since the Pleistocene times, is proved by tlie presence of other 

 groups of mammalia — those confined now to cold and to hot countries. They afford 

 evidence that at first sight appears conflicting, but which upon analysis we shall find to 

 be very conclusive, that the climate in Britain, in those days, was very much more severe 

 than at present. Prom the conditions imder which the surviving Pleistocene herbivores 

 now live, we can infer those under which they lived in Britain in that early period. The 

 northern group of Pleistocene mammalia, living only now in a severe continental climate, 

 consists of species that have very different powers of resisting cold and heat. Thus, the 

 musk-sheep is found now only under the lowest temperatures in the vast treeless "Barren 

 Grounds" of North America, while the reindeer lives also in the forests, along with the 

 elk, of the Europseo-Asiatic and North American continents. The red deer and the bison 

 range up to the edge of the province inhabited by the latter animals. The lemmings 

 live under a very severe climate, while the marmots are found in the higher and colder 

 districts in Southern Europe and Central Asia. Each of these northern species is 

 dependent upon the oscillation of the climate for its particular habitat in a given year, 



