THE MOUSE TRIBE. 



133 



Morayshire, while abroad it ranges from France across Asia to China. Its general 

 habits are the same as those of the field-vole, but it is said to be more generally 

 found in sheltered situations, and is especially fond of visiting gardens. 



There is, however, a great probability that both the bank-vole and the red- 

 backed vole (J/, gctppt ri) of North America, are merely local varieties of the Arctic 

 vole (M. rul Hi's), which inhabits the circumpolar regions of both hemispheres; 

 their differences in coloration being merely such as might well be due to the 

 varying climatic conditions of the countries they severally inhabit. 



The Alpine vole (J/. tiivaMs), which is the last species to which 

 we refer at any length, is interesting on account of the elevated 

 regions forming its habitat. It is a small species with a relatively long tail: the 



Alpine Vole. 



the alpine vcji.k ,-; nat. size). 



total length being about 7 inches, of which slightly more than half is taken up 

 by the tail. The cars are large : and the number of prisms in the first upper molar 

 tooth is the same as in the water-vole. The colour varies from brownish grey 

 above and greyish white beneath to pure white. This species has an exceedingly 

 limited distribution, being confined to the Alps and Pyrenees, where it ranges from 

 an elevation of about four thousand feet to the limits of perpetual snow. It is, 

 indeed, most abundant near the snow line, above which it also sometimes wanders 

 in search of the scanty vegetation which exists at such altitudes. Not only is the 

 Alpine vole found in these dreary regions during the short season when the ground 

 is more or less free from snow, but it likewise remains there from year's end to 

 year's end. Accordingly, for upwards of nine or ten months of the year, it lives 

 beneath a deep pall of snow. Here it makes regular runs, along which it travels in 

 search of food when the supply hoarded for winter use becomes exhausted. No 

 other known mammal leads a similar existence. 



