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 (M. gapperi) of North America, are merely local varieties of the Arctic 
vole (I rutilus), which inhabits the cireumpolar 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 (M. nivalis), 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. 



























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THE ALPINE VOLE (2 nat, size). 
total length being about 7 inches, of which slightly more than half is taken up 
by the tail. The ears 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. 
