THE MICE AND RATS 



315 



neglected by the stock. In orchards that are allowed to 

 grow up to weeds and grasses, they are also likely to de- 

 velop in such abundance as to injure the trees seriously 

 by gnawing the bark. They are often destructive to young 

 trees in nurser- 

 ies, especially 

 where clean cul- 

 ture is not given. 



The rate of 

 reproduction 

 of the Prairie 

 Mouse is slightly 

 less than that of 

 the Common 

 Meadow Mouse, 

 there being 

 fewer young in 

 each litter. The 

 climatic condi- 

 tions as to 

 drought in sum- 

 mer and cold in winter, and the less general presence of 

 sheltering materials, also tend to check its increase. But 

 it often becomes far too abundant and destructive. 



The runways of the Prairie Mouse and the Common 

 Meadow Mouse are generally made above the soil surface, 

 though commonly beneath the shelter of overhanging grasses 

 or other vegetation. This is an easy way to distinguish 

 them from the nearly related Pine Mouse, which makes its 

 molelike runways through the soil itself. 



. This Pine Mouse in the typical form or that of a closely 

 allied geographical race, is distributed over most parts of 

 the United States. It makes its home in woodlands rather 



Hyacinth Bulbs eaten by Pine Mice 



