TREASURY DEPARTMENT. 
Public Health and Marine-Hospital Service of the United States. 
Walter Wyman, Surgeon-General. 
HYGIENIC LABORATORY.-BULLETIN No. 20. 
Ivl. J. ROSEIXAU, Director. 
April, 1905. 
A ZOOLOGICAL INVESTIGATION 
INTO 
THE CAUSE, TRANSMISSION, AND SOURCE 
OF 
ROCKY MOUNTAIN “SPOTTED HEVER.” 
BY 
CH. SXILETS. 
WASHINGTON: 
GOVERNMENT PRINTING OFFICE. 
1905. 
