216 FIELD MUSEUM or NATURAL HISTORY ZOOLOGY, VOL. XL 



bottom. In summer its food mainly consists of the roots of grass and 

 weeds. Lantz states (7. c., p. 17) that it is very fond of the roots of 

 the wild, white morning-glory (Convolvulus septum) . In fall and winter 

 it eats seeds, grain and the bark of trees, and it often does considerable 

 injury to fruit orchards. I have often seen them sit up on their haunches 

 and eat their food, holding it in their fore paws after the manner of a 

 Squirrel. They do not hibernate in winter but pass most of their time 

 in runways beneath the snow, and it is claimed they store up more or 

 less food for use during the cold weather. 



Lantz says, "The habit of storing food seems to be less common in 

 this country than with Old World species, but it is far from rare. Caches 

 of food are often found, which show that in times of abundance the 

 animals store away more than is needed for immediate use." (I. c., 

 p. 14.) 



Dr. C. Hart Merriam in describing the habits of this species says:* 

 " In the beginning of winter, when the ground is frozen for some distance 

 below the surface, it abandons its burrows and lives entirely above 

 ground. Its nests of dry grass then lie flat upon the surface, without 

 attempt at concealment, and are soon buried in the snow. As winter 

 advances and the snow becomes deeper, the Meadow Mice regularly 

 betake themselves to their nests for rest. The heat from their bodies 

 soon melts the snow in contact with and immediately adjoining the 

 nests, which, from the contmued operation of the same cause, come to 

 be surrounded by slowly-growing, dome-shaped chambers. These in- 

 crease in size until the spring thaws, in March and April, melt away 

 their roofs, thus admitting the light and cold. They are then deserted. 

 During snow-shoe tramps over fields at this season I have often noticed 

 holes, from a few inches to a foot in diameter, appearing as if sharply 

 cut in the surface. On inspection, they invariably proved to be the 

 summits, of these dome-shaped cavities, and a nest was always found 

 at the bottom of each, surrounded by a zone of bare ground. They 

 ranged from one to two feet (approximately 300 to 600 mm.) in diam- 

 eter, and most of them were two feet in height. From the bottom of 

 each chamber numerous runways and burrows penetrated the snow in 

 all directions. Some followed along directly upon the ground, while 

 others sloped upward at various angles. Many ran horizontally at 

 varying levels, resting upon the dense strata that indicated the surface 

 lines at different times during the winter. Near each nest was one or 

 more burrows that reached the surface and contained considerable 

 accumulations of the animal dejections. These seemed to be watch 

 holes where the Mice came regularly to look at the prospect outside." 



* Mamm. Adirondack Reg., 1886, p. 272. 



