8 NORTH AMERICAN FAUNA. 



the edges of woods, and show a marked preference for moist locations. 

 During the summer Jumping Mice are often seen in meadows and fields, 

 and are more readily detected during the haying season than at other 

 times, when they are driv r eu from their hiding places while the grass is 

 being cut. When disturbed they move off by a series of frog like leaps, 

 and often remain motionless after a jump or two, especially when 

 frightened from a nest. In leaping they are greatly assisted by their 

 long tails, which aid in preserving their balance as in the case of other 

 animals similarly endowed. If, by any accident, a portion of the tail is 

 lost, the power of balancing is greatly impaired, and the animal, if 

 startled, seems unable to pursue a direct course because of failure to 

 land properly on its feet. Some of the earlier writers ascribe to the 

 animal the power of leaping 4 or 5 yards. Such statements are probably 

 exaggerated, but it is certain that Zapus does possess remarkable leap- 

 ing powers, and when disturbed will jump G or 8 feet, and under some 

 circumstances perhaps much farther. In their chosen haunts these 

 mice do not follow beaten paths or runways like many small mammals, 

 notably meadow mice, but seem to wander rather indiscriminately, 

 availing themselves to some extent of natural pathways or open places. 



The birth of the young (five or six in number) which occurs in a nest, 

 ordinarily underground but sometimes placed in a hollow tree, usually 

 takes place in May or June. Sometimes, however, it occurs as late as 

 September; from which it seems probable that a second litter is raised, 

 or that the breeding season continues throughout the summer. Three 

 specimens obtained by my brother at Wilmington, Mass., September 25, 

 1897, which with their parents were turned up by a plow, were so young 

 that the posterior upper molars had just appeared. 



During the latter part of summer Zapus makes a globular nest of 

 grass about 4 inches in diameter, with a small entrance at the side- 

 All that I have seen were on the ground in meadows among thick grass 

 or small bushes. One that I examined was made entirely of the straight 

 narrow leaves of grass, and was a very beautiful little home; but though 

 seemingly compact, it was so frail that it was impossible to preserve it. 

 These nests are usually occupied by two individuals, presumably a pair, 

 and seem to be used only at the close of the breeding season. 



The hibernation of Zapus has been frequently noticed and several 

 interesting articles have appeared mainly on this habit. 1 All the species, 

 so far as known, hibernate during winter, though in one, at least, hiberna- 

 tion is not always complete that is, individuals may awake and come 

 out during warm intervals, after the manner of the common skunk. Dr. 

 Merriam mentions having seen Jumping Mice abroad in northern New 

 York on several occasions during the unusually mild winter of 1881-82. 

 Messrs. H. H. and C. S. Brimley report that they have no positive evi- 

 dence of the hibernation of Zapus liudsonius amcricanus at Raleigh, 

 N. C., although they add that the animal is too rare to enable them to 



'Davies, Trans. Linn. Soc. London, IV, p. 155, 1798; Barton, Trans. Am. Philos. 

 Soc., VI, p. 143, 1804 ; Tenuey, Am. Nat., VI, p. 330, 1872. 



