THE VOLES. 



115 



The VOLES (Arvicolince), which, next to the true Hats and Mice, form the most important group 

 of Muriclse, are represented in the northern parts of both hemispheres. The brain-case in these 

 animals is rhomboidal when looked at from above, the frontal region of the skull is much contracted, 

 and the zygomatic arch stands out very far. The infra-orbital opening is as in the Murinse. The 

 molars are so constructed of alternating triangular prisms that the whole margin is enclosed by deep 

 angular folds of enamel. These are mouse- and rat-like Rodents of a rather stout build, with the 

 limbs and tail of moderate length, or short, and the latter more hairy than in the true Murines. The 

 ears are short, often nearly concealed beneath the fur. 



The true Voles (genus Arvicola) number about fifty known species, which have been arranged by 

 various writers under a considerable number of sub-genera, generally corresponding to differences in 

 mode of life. Three species, representing three of these groups, are found in. Britain, and may serve 

 to illustrate the natural history of the Voles. The largest of these is the well-known WATER VOLE, or 

 Water Rat, as it is more commonly called (Arvicola amphibius), an animal rather smaller than the 

 Common Rat, and having, like all the Voles, the muzzle considerably blunter, and the tail a good deal 

 shorter and more hairy. Although thoroughly aquatic in its habits, the feet of the Water Vole are 

 not webbed ; they have five toes, but the thumb in the fore feet is very short. The general colour of 

 the fur is reddish-brown, mixed with grey on the upper surface, and yellowish-grey beneath ; the ears 

 are nearly concealed in the fur ; and the incisor teeth are deep yellow in front, and very strong, pre- 

 senting a considerable resemblance to those of the Beaver, to which great Rodent the Voles were 

 formerly considered to be related. It is very widely distributed, being found in all parts of Europe, 

 and stretching right across Central and Northern Asia, to China, the Amoor region, and the 

 Sea of Okhotsk. In Ireland, however, it is not found. Its habits vary a little in different 

 localities, but in general it "haunts the banks of rivers, in which it burrows to a considerable dis- 

 tance. In the water it is very active, swimming and diving with the greatest facility, and it is 

 here that it seeks its food, which appears to consist exclusively of vegetable substances. Professor 

 Bell says: "A decided preference is shown, during the summer months, for the inner or concealed part 

 of some species of sword-flags, which is very succulent and sweet-tasted. As this portion is usually 

 below water, the animal gnaws the plant in two near its root, when it rises to the surface, and 

 being conveyed to some sound footing, is consumed at leisure. In default of its more favourite food, it 

 will make a satisfactory meal on the common duckweed. Only the green, and fleshy leaf is eaten, the 

 roots and other fibrous parts being rejected. While feeding on this plant, the creature sits like a 

 Squirrel on its haunches near the water's edge, and taking up a lump of the soft and slimy-looking 

 mass in its fore paws, eats a small part only, and letting 

 the remainder fall, takes up some more in the same 

 manner." The accusation sometimes brought against the 

 Water Vole of eating worms and insects, and even of 

 destroying fish - spawn, young fishes, and even young 

 ducks, seems to be entii*ely unfounded. In the winter 

 the Water Voles will feed on turnips, mangel-wurzel, 

 and other roots, and also upon the bark of osiers and 

 willows, to which they do considerable damage ; and in 

 some localities they appear to frequent gardens at all 

 seasons of the year, burrowing in the ground, and 

 feeding luxuriously upon the produce of the gardener's 

 labour. Their greatest activity is in the twilight, but in 

 quiet situations they are to be seen abroad during the day. The female produces from two to six 

 young at a litter : twice in the year in Britain, according to Professor Bell ; three or four times in the 

 course of the summer, according to Brehm and other Continental naturalists. 



A second British species is the FIELD VOLE, or Short-tailed Field Mouse (Arvicola agrestis), 

 which is less than half the size of the Water Vole, and has the tail only about one-third the length of 

 the body, instead of half that length. In the general form of the head and body the two species are 

 a good deal alike, but the ears project farther beyond the fur in the Field Vole. The general 

 colour of this species is greyish-brown, becoming tinged with reddish or yellowish on the sides ; the 



ETH OF THE WATER RAT. 



