494 MAMMALIA, 



and white beneath ; the sides of the head are orange. The 

 colour, however, varies a good deal, but is always brightest in the 

 female sex. The feet are long and delicate, and covered with 

 fine yellowish hairs in front and white at the sides. Tail 

 scantily clothed with hair. Length, as a rule, two and a half 

 inches ; tail two inches. The period of gestation is said to 

 be three weeks ; the young vary from five to eight. This 

 species builds a beautiful nest lined with fine hair and grass, 

 said to be split up by the animal's teeth. The nests are often 

 no larger than an orange, and sometimes quite round. This 

 breeding-nest is much like that of a bird. A winter nest is 

 also formed, where they pass the cold months of the year, in 

 stacks, &c. The favourite localities are amongst reeds, long 

 gras.s, and low shrubs, where the nest is often placed some Avay 

 off the ground. It is no unusual thing for M. messorius to take 

 the nest of a warbler and build its own in and over it. They 

 may sometimes be found in wheat- and barley-fields, but never 

 in any great number. These mice feed on corn and various 

 seeds, also flies and other insects, and they are known to eat the 

 buds of gooseberries and currants. Hazel-buds are also eaten. 



The Common Mouse (M. muscvlus) need not be referred to, 

 being well known. It is chiefly this species that we find so 

 abundantly in corn-fields, and not M. messm-ius, as is generally 

 supposed. 



AevicolidjE or Voles. 



These can be told from the true Eats and ]\Iice by the more 

 solid body, thick head, and blunt snout, by the absence of ex- 

 ternal ears, which are covered in fur, and by scales being 

 found wanting on the tail, which may be partly hairy. 



There are three common species — namely, the "Water- Vole 

 [Arvieola amphih/'us), the Bank-Vole (A. glareolvs), and the 

 Field- Vole [A. agresti.<). None of these are found in Ireland. 



The Fiehl-Vole (A. co/mififi), sometimes called the short-tailed 

 field-mouse, is a small vole with dark-brownish back and grey 



