REPORT OF THE CHIEF OF THE BUREAU OF BIOLOGICAL SURVEY. 



U. S. Department of Agriculture, 



Bureau of Biological Sur\t;y, 

 Washington^ D. 6'., October 4? 1910. 

 Sir: I have the honor to transmit herewith a report on the work 

 of the Biological Survey for the fiscal year ended June 30, 1910, 

 with outline of work for 1911. 



Respectfully, H. W. Henshaw, 



Chiefs Biological Siu^ey. 

 Hon. James Wilson, 



Secretary of Agriculture. 



WORK OF THE BIOLOGICAL SURVEY. 



The work of the Biological Survey as laid down by Congress is 

 conducted under three general heads: (1) Investigations of the 

 economic relations of birds and mammals to agriculture; (2) invCvS- 

 tigations concerning the geographic distribution of animals and 

 plants with reference to the determination of the life and crop belts 

 of the country; (3) supervision of matters relating to game preser- 

 A^ation and protection, and importation of foreign birds and other 

 animals. 



GROUND squirrels AND SPOTTED FEA-ER. 



During the year an important investigation was begun, in coopera- 

 tion with the Bureau of Entomology and the state authorities of 

 Montana, to discover the original source of infection of the so-called 

 spotted fever of Bitterroot Valley, Montana, and other parts of the 

 Rocky Mountain region. This fever, which in certain localities is 

 usualh' fatal, is believed to be disseminated by ticks which are har- 

 bored on ground squirrels and perhaps other mammals indigenous 

 to the region. A first and very important step in any attempt to 

 eradicate the disease is to discover the particular mammal or manunals 

 which act as carriers. Two assistants of the SurA'ey spent several 

 months in the Bitterroot Valley studying the distribution and habits 

 of its mammals and trapping large numbers so as to secure for study 

 by entomologists the ticks infesting them. Individuals showing 

 signs of disease were turned over to experts for examination witli a 

 view to the discovery of the organism causing the fever. It is be- 

 lieved that by these cooperative efforts definite progress has been 

 made in the study of the etiology of this disease. 



549 



