ECONOMIC ZOOLOGY ENTOMOLOGY. 249 



of which two are described as uew to science. A brief account is given of the 

 distribution, habits, and economic relations of muslirats, a more extended 

 account of which, by D. E. Lantz, has been previously noted (E. S. R.. 23, 

 p. 356). 



A liey to adult muskrats in fresh pelage, a bibliography of 55 titles, and a 

 colored map showing the distribution of muskrats as known at present are 

 included. 



A study of the food of moles in Illinois, J. A. West (Bill. III. Htafc Lab. 

 Nat Hint., 9 (1910), Art. 2, pp. i//-22).— " The contents of the stomachs here 

 reported have shown perhaps a greater amount of insect food and somewhat 

 smaller ratios of eailhworms than those examined by other writers, but there 

 is a substantial agreement to the effect that half or more of the food of the 

 mole consists of insects and their larvae, most of them noxious. So far as its 

 food is concerned, the mole is thus beneficial, on the whole. There is no direct 

 evidence that it will eat potatoes or other tubers, but circumstantial evidence 

 on this point is so strong that the mole must remain under suspicion, even 

 admitting that mice of herbivorous habit may occupy mule runs in fall. In this 

 paper it is shown, for the first time, tliat corn may form an important item of 

 the food of moles; that recently planted corn is sometimes destroyed by them; 

 and that if numerous in corn fields in spring, they are capable of doing con- 

 siderable damage there." 



A plague-like disease of rodents, G. W. McCoy iPuJj. Health and Mar. 

 Uosp. Sere. U. S., Pub. Health Bui. J,3, 1911, pp. 53-71).— "A disease which pre- 

 sents lesions very similar to those of plague has been found among ground 

 squirrels. The disease is readily transmitted to guinea pigs, mice, rabbits, 

 monkeys, and gophers, and plague-like lesions are produced in at least some of 

 these animals. liats are but moderately susceptible to the infection. Cats, 

 dogs, and pigeons appear to be immune. 



"The disease may be transmitted artificially by subcutaneous, cutaneous (vac- 

 cination), nasal, and intraperitoneal inoculation. The mode of transmission 

 in nature is unknown, but there is some experimental evidence that suggests 

 that fleas may serve as carriers. The disease probably is not spread by mere 

 contact of healthy with infected animals. The infectious agent has not been 

 isolated. On account of the number of species susceptible, it seems likely that 

 it is bacterial, not protozoan. The causative agent is present in the circulating 

 blood, as well as in the various tissues where it causes focal lesions. The 

 thermal death point of the organism as it is found in the animal's body is 

 between 55° and 60° C. Several observations appear to indicate that the 

 disease is a febrile one." 



A contribution to the study of rat leprosy, D. H. Cttrrie and H. T. Holl- 

 MANN (Pub. Health and Mar. Hasp. Serv. U. S., Pub. Health Bui. .'fl, 1911, pp. 

 13-32). — Following a review of the literature relating to the subject notes by 

 the authors on 12 cases of rat leprosy are recorded. The conclusions drawn 

 are as follows : 



" In some cases of artificially acquired rat leprosy the onset is with broncho- 

 pneumonia, accompanied by a septicemia and without other demonstrable 

 lesions. In other cases of this disease pneumonia is a very early lesion, but 

 we can not positively state that it is always the first lesion. The animal may 

 die in the pneumonic stage before other lesions present themselves or it may 

 develop pneumonic symptoms and recover from the same only to develop later 

 the well-known lesions of chronic rat leprosy ; or, again, the pneumonia may 

 persist until after the development of the lesions of the skin and abdominal 

 viscera. During the stage of the disease in which the animal is very ill cer- 

 tain mites (Lcelaps echidmnus) were found to be very numerous on the ani- 



