538 ANNUAL KEPORTS OF DEPARTMENT OF AGRICULTURE. 



by destroy ing insects it also attacks crops to some extent, especially 

 seed corn, although much of the damage attributed to this animal is 

 due to field mice, which habitually use the runways of the moles. 

 Etl'orts are being made to secure the stomachs of moles from ditlerent 

 agricultural sections of the country with the view of increasing our 

 knowledge of the food habits of this little mammal, and a bulletin 

 will be issued defining its economic status and explaining methods of 

 destroying it when necessary by traps and poisons. 



FUR-BEARING ANIMALS. 



The present high price of furs is due less to passing fashion than 

 to the actual and growing scarcity of fur-bearing animals. As 

 wearing apparel and for personal adornment furs occupy a place 

 of their own, and there seems to be no acceptable substitute for 

 them. For years the demand for furs has been greater than the 

 supply, and, chiefly as a result of the encroachments of civilization 

 on the breeding range of the animals and the unceasing activity of 

 trappers, the number of fur bearers has been greatly reduced. If in 

 the future furs are to be worn by any but the rich, it would seem that 

 recourse must be had to fur farming on a large scale. The fur bearers 

 best adapted for artificial breeding appear to be foxes, minks, and 

 martens. Attempts to raise these animals, especially the first two 

 named, are being made by private parties in various parts of this 

 country and Canada. So far none of these enterprises appear to have 

 passed the experimental stage, although a number of breeders of the 

 silver fox claim to have made the business remunerative. It is be- 

 lieved that under suitable climatic conditions and with a fair under- 

 standing of the nature and methods of the business, the rearing of 

 foxes and minks, and perhaps also martens, can be made a permanent 

 and profitable occupation. The experiments noAv under way are 

 being watched with great care, and all possible information is being 

 obtained from breeders as to the treatment and feeding of the animals, 

 with a view of ultimately issuing bulletins on the subject to supple- 

 ment the two already published on fox farming and the muskrat 

 industry. 



COOPERATIVE WORK IN RELATION TO SPOTTED FEVER. 



In cooperation with the Bureau of Entomology and the State ex- 

 periment station of Montana much work was done by the Biological 

 Survey during the year in Bitterroot Valley, Mont., to determine 

 which of our native mammals act as hosts of the fever tick and thus 

 aid in spreading spotted fever. In one or another stage of develop- 

 ment fever ticks were found on no fewer than 18 of the wild n.am- 

 mals of the district. Some of these, like the larger game animals, 

 are so scarce and inhabit places so remote from the habitations of 

 men that they probably have little to do with the spread of the 

 disease. Others, however, particularly ground squirrels, woodchucks, 

 pine squirrels, and chipmunks, are very numerous in both cultivated 

 and waste places contiguous to farms and villages, and any plan for 

 permanently freeing the valley from fever ticks necessarily involves 

 the extermination or the material reduction in numbers of these 

 mammals. Thorough investigations are now being made by one of 



