194 THE FORAGE AND FIBER CROPS IN AMERICA 



223. PRAIRIE MARMOTS (Cynomys ludoricianus Ord.), also called prairie 

 dogs, belong to the squirrel family (Sciuridac), though they are much larger 

 than the species described above. They are more closely related to the wood- 

 chuck or ground hog than to the other Sciuridae. They are the most 

 gregarious of the whole family. Their natural enemies are wolves, foxes, and 

 rattlesnakes. A spoonful of poisoned wheat placed in the mouth of each 

 burrow is widely used to combat them. 



224. MEADOW MOUSE (Microtus pennsylvanicus Ord.) and prairie meadow 

 mouse (M. austerus Le Conte) are two important species of the mouse family 

 (Muridae), which comprises 66 species and sub-species of continental range. 

 They are short-eared, short-tailed, thick-set and 6 to 6.5 inches long; reddish- 

 brown above and whitish below. They inhabit marshes, meadows, pastures, 

 lawns, orchards, gardens, and cornfields. Their natural enemies are pickerel 

 fish, cats, foxes, weasels, crows, marsh hawks, hen hawks, winter hawks, while 

 they form the chief diet of owls. 1 



225. Time of Cutting for Hay. The number of cuttings will 

 depend on climate and soil and the stage at which it is cut, and 

 ranges from two to five or more cuttings. Probably three 

 cuttings are the most common. Between the 39th to the 42d 

 parallels of latitude in the United States, the usual period is 

 about as follows : first cutting May 25 to June 5 ; second cutting 

 July i to 20; third cutting August 20 to October I. It is gen- 

 erally thought advisable to leave a fair growth of alfalfa upon 

 the land when it goes into winter quarters. In the sub-humid 

 regions and in the irrigated regions the practise is to cut when 

 the alfalfa is coming into blossom, estimated to be from one- 

 tenth to one-third the total flowers. This is not a safe rule for 

 humid climates. The failure in humid climates often results 

 from a failure to cut alfalfa soon enough, particularly the first 

 cutting. The crop should be cut as soon as the lower leaves 

 begin to turn yellow, even though few, if any, flowers show, 

 as is usually the case. In humid regions alfalfa is subject to 

 spot disease, and if the plants are left to stand after the lower 

 leaves turn yellow, in a short time most of the leaves become 

 affected and the crop is of little value for hay. Often growers 

 are tempted to leave an unsatisfactory growth with the 



1 In this connection, see Minnesota Sta. Bui. No. 88 (1904), pp. 144-165. 



