THE BRITISH MAMMALS : THEIR GENERA AND SPECIES. 51 



Mus. Plates xi. and xii. RODE NT I A . 

 Head and body less than five inches 



37. minutus, HARVEST MOUSE. Hind feet brown ; ears short and 



broad. 



38. sylvaticus, WOOD MOUSE. Hind feet long and white ; brownish 



patch on chest. 



39. sylvaticus wintoni, YELLOW-NECKED MOUSE. Hind feet long and 



white ; yellow band across chest. 



40. musculus, COMMON MOUSE. Hind feet greyish; ears long and 



rounded . 



Head and body more than five inches 



41. rattus, BLACK RAT. Tail longer than head and body. 



42. decumanus, BROWN RAT. Tail shorter than head and body. 



The Rats and Mice have no canine teeth and no premolars. 

 The incisors a single pair are narrow and have no grooves ; those 

 in the upper jaw are wedge-shaped, those in the lower are compressed 

 and pointed. The molars three in each jaw have roots. One of 

 the upper three has about eight tubercles arranged in three rows, the 

 middle row of three being the largest, the next molar has about five 

 also placed in three rows, the third has four only, which are no larger 

 than those in the outer lines of the other teeth. In the fore feet the 

 thumb is rudimentary, and has a nail instead of a claw. The tail is 

 long, round, and ringed with scales The muzzle is more or less 

 pointed and bare at the tip. 



The Harvest Mouse is pale orange brown above and white below, 

 the hind feet being brown. In length the head and body measure 

 about two and a half inches, the tail, which is prehensile, or nearly so, 

 being about half an inch less. The ears are broad, and as high as 

 the distance from their base to the throat. The paws are used for 

 grasping, the Harvest Mouse climbing and clinging to a wheat stalk 

 much as a monkey does to a tree ; and a full-size stalk will hardly 

 bend with his weight, for five of these mice go to the ounce. There 

 are half a dozen or so blind, naked young at a time, reared in a 

 globular nest as large as a cricket ball, the aperture of which is 

 closed when the mother is away in search of food. The nest is built 

 among the stalks of standing corn, or, as Gilbert White first found 

 it, suspended in the head of a thistle, " most artificially platted, and 

 composed of the blades of wheat." But the young Harvest Mouse 

 is not always cradled like this, for there are two or more litters in a 

 year. The winter is passed in a burrow in which a small store of 

 food is laid up for use at odd times should the sleep be broken, or it 

 is passed in a rick where corn is plentiful. The food includes worms 

 and insects as well as seeds. Like the dormouse the Harvest Mouse 

 fattens up for the trials of winter, and appears in spring of much 

 more slender build than at other times. He is not found in Ireland, 

 but ranges from the south of Scotland into Siberia. 



The Wood Mouse, otherwise the Long-tailed Field Mouse, is about 

 double as large as the foregoing, his head and body measuring nearly 



