52 THE BRITISH MAMMALS : THEIR GENERA AND SPECIES. 



four and a half inches and his tail about four. He is easily recognised 

 by his yellowish brown upper parts, his white underparts with the 

 brown patch on his breast, and his long white feet. His head is long, 

 and his oblong, oval ears are more than half its length. The young, 

 from three to five at a time, four or more litters in a year, are reared in 

 a nest in a thick tuft of grass or elsewhere. The winter is spent in a 

 hole under the trunk of a tree, or similar place, sometimes in an out- 

 building. This is plentifully stored with acorns, nuts, peas, beans, 

 grain, and sundries, for, during the very partial hibernation, the 

 Wood Mouse wakes often and eats much, and is of so prudent a 

 disposition that he is always prepared for a siege. He lives and 

 flourishes in several varieties all over Europe, including Ireland. 



The Yellow-necked Mouse is reddish grey above, brighter along 

 the flanks and legs. It has a clear yellowish brown band across 

 the chest in front of the fore legs, about a quarter of an inch wide, 

 spreading out upwards and downwards in the middle. The eyes 

 are prominent ; the ears are large ; the tail is long ; and the hind 

 feet are long and white. The skull is an inch and an eighth in 

 length, narrower, longer, and stronger than that of the preceding,and 

 having the superciliary ridges much better developed. This mouse 

 measures nine inches over all, the tail being about half the length, 

 sometimes rather more, sometimes less. It was added to the 

 British list in 1894 as M. flavicollis, a Scandinavian species from 

 which it differs, and it is now regarded as the most noticeable 

 variety of M . sylvaticus. It is found side by side with the common 

 Wood Mouse in Herefordshire, but does not interbreed with it, just 

 as the small West of Ireland form, M. sylvaticus celticus, lives in 

 the Isle of Lewis along with another variety, M. sylvaticus hebridensis. 



The Common Mouse in its typical form is greyish brown above, and 

 never white below, though it may be of several shades of fulvous or 

 dusky grey. In head and body it measures three inches and a half, and 

 the tail is as long or longer. The ears are rounded, and extend to 

 the eye when laid forward. The eye is black and small. In both 

 jaws the third molar is diminutive, being about a third the size of 

 the second. The Common Mouse, though mostly confined to 

 human dwellings, is also met with in the fields. It is practically 

 omnivorous, with a partiality for most things eaten by man, and is 

 reared in a comfortable nest made of small pieces of straw, frag- 

 ments of dress material, paper, and other household sundries. The 

 female begins to breed when less than a year old, and she has five or 

 more litters a year, and from four to seven in a litter, the young being 

 born blind and naked, but developing so quickly as to be able to shift 

 for themselves in a fortnight. Now and then they sport, and from these 

 variations have come the fancy mice of several colours, including 

 the usual albino, of which boys and others have made pets, which 

 is seldom the fate of the typical form, though it seems to be the in- 

 evitable companion of man. 



The Black Rat is blackish above and ashy below, with flesh- 

 '.oloured legs and feet. The head is slender, the muzzle sharp and 



