24 A.\ ECONOMIC STUDY OF FTELD MICE. 
Field mice injure early peas and other vegetables growing in open 
grounds, and pine mice often destroy potatoes in the ground. In the 
fall vegetables piled on the ground or stored in pits are liable to 
attack-. Among these are potatoes, beets, turnip-, carrot-, parsnips, 
cabbage, sweet potatoes, and especially celery. Apples, pears, and 
other fruits are eaten also. 
In parts of eastern Maryland pine mice have recently (1907) been 
quite destructive to melon and cantaloupe crop-. The animals 
destroy the seed and eat the roots of the plants during the growing 
season. The injury was greatest on sandy lands which had not been 
plowed before planting, but had been smoothed with a drag, leaving 
the mouse tunnels below undisturbed. In some fields seed had been 
planted three times, but by the middle of July all hope of a crop had 
been abandoned. 
DAMAGE TO SMALL FRUITS. 
Blackberries, raspberries, grapes, currants, gooseberries, and straw- 
berries are often badly damaged by field mice, and when the animals 
are abundant whole plantations are ruined. Strawberries are espe- 
cially liable to injury because of winter mulching and also because 
the plants themselves furnish excellent food and shelter for the 
animals. 
Fallen leaves in autumn and snow in winter drift and collect along 
rows of blackberry, raspberry, gooseberry, and currant bushes and 
furnish cover for mice, which work along the rows and girdle the 
green steins; and when dead canes are left uncut and weeds are per- 
mitted to grow up among them, the resulting tangle adds much to 
the liability of attack. Winter mulching of small fruits also in- 
creases the danger, and if practiced the utmost care should be taken 
to clean surrounding areas. 
DAM: AGE TO XI RSERV STOCK. 
In many sections of the United States and southern Canada nursery 
stock is injured by field mice. The actual loss varies from year to 
year and is difficult to estimate. Occasionally the havoc has been so 
complete that few marketable trees remained. It was estimated that 
during the winter of 1901-2, nurserymen in the vicinity of Rochester, 
X. Y., sustained losses amounting to $100,000." 
Damage to standing nursery stock is done usually under cover of 
snow, and hence is greatest in seasons of deep shoavs that remain long 
upon the ground. In addition to girdling trees above the surface 
of the ground, meadow mice sometimes burrow beside the trunk and 
attack the roots (PI. III. fig. 2). Pine mice usually begin their 
a New York Sim, April 27, 1902. 
