JUMPING MICE AND JERBOAS. in 



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 3 inches, and that of the tail about 5 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-coloured edges, and the long and nearly naked tail is tipped 

 with a pencil of hairs. 



Distribution and The geographical range of the jumping mouse is very large, 

 Habits. extending from the cold regions of the Great Slave Lake and 

 Hudson's Bay to Arizona and Mexico ; although in the latter districts it appears 

 to be restricted to the mountains. In British North America and the northern 

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



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

 generally 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. E. 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 8 or 10 feet in 

 length, but these distances rapidly decline to about 4 feet. This is not always 

 the case, however, for it frequently 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 irregu- 

 larities 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, grain, wild berries, 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 locality and the temperature of the season. In mild winters the hibernation 

 is often interrupted for longer or shorter periods. The underground nest is 

 carefully made of grass, in which the little animal lies tightly curled up, with 



