U. S. DEPAR I Ml \ I I >F AGRICl I 1 URE 
BIOLOGICAL SIKVKY BULLETIN Ra 81 
i ii u: i mi i;i;i \M 
\ ECONOMIC STUDY OF FIELD MICE 
(GENUS MICROTUS) 
IiY 
DAVID E. LA XTX 
Assist wt. Biological Survey 
WASHINGTON 
GOVERNMENT PRINTING OFFICE 
1907 
