THE JUMPING MOUSE 1283 



the presence of four pairs of rooted cheek-teeth in each jaw, by the vertebrae of the 

 neck being entirely separate from each other, and by the long hind-limbs being 

 furnished with five complete toes, of which the metatarsal bones are separate. In 

 the fore-limbs the first toe is rudimental, and furnished with a flat nail. Well- 

 developed cheek pouches are present. 



In general appearance this animal resembles a mouse with elongated hind-limbs 

 and a very long tail; the degree of elongation of the hind-legs not being so great as 

 in some other members of the family. The length of the head and body is a little 

 more than three inches, and that of the tail about five inches, although there 

 is a considerable amount of individual variation in the relative proportions of 

 the latter. In the summer coat the fur is brown above, yellowish on the flanks, and 

 white below, but in the winter it is uniformly brown. The moderate-sized ears are 

 black with light-colored edges, and the long and nearly naked tail is tipped with a 

 pencil of hairs. 



The geographical range of the jumping mouse is very large, extend- 



. ing from the cold regions of the Great Slave Lake and Hudson's Bay 

 and Habits 



to Arizona and Mexico, although in the latter districts it appears to be 

 restricted to the mountains. In British North America and the northern part of 

 the United States it ranges from the Atlantic to the Pacific coasts. 



This species differs from most of its allies in not being strictly nocturnal, gen- 

 erally venturing forth early in the evening, and not unfrequently being abroad during 

 the day. It likewise frequents more wooded and damper situations. The following 

 excellent accounts of its habits was communicated to Dr. Hart Merriam by Mr. 

 K. Slade, who observes that, " the long-tailed jumping mouse inhabits high land or 

 low land, forest or pasture, cultivated field or swamp, and appears to be equally at 

 home in either, and not numerous in any situation. It possesses a momentary 

 agility second to no other Rodent, and a muscular strength of enormous power for so 

 small a creature. When suddenly disturbed, it often moves away in a direct line, 

 the first three or four leaps being eight or ten feet in length, but these distances 

 rapidly decline to about four feet. This is not always the case, however, for it fre- 

 quently takes an irregular course and jumps at divers angles for several successive 

 leaps, keeping the same general direction, or changing at will. It can double, and 

 quickly too, if pursued, and by its manoeuvres and instantaneous squattings can 

 elude a hawk or an owl, and its spontaneous irregularities enable it to escape being 

 brained by a weasel, or swallowed whole by the common black snake. It feeds upon 

 the buds, leaves, and twigs of many kinds of plants; upon seeds, grains, wild ber- 

 ries, chestnuts, acorns, grass, and to some extent upon the bark of shrubs. As a 

 rule, three litters are produced in a season, each consisting of from two to four 

 young." In leaping, the successive springs are made with such rapidity that 

 the feet of the animal seem scarcely to touch the ground. The nest is placed 

 in a variety of situations, sometimes in the hollow stump of a tree, more frequently 

 under logs of timber, often in clefts of rocks, and occasionally a short distance from 

 below the surface of the ground in an open field. 



The jumping mouse hibernates during the winter in a hole deep down in 

 the ground; but the length of the sleep appears to depend upon the latitude of the 



