LETTER OF TRANSMITTAL. 



U. S. Department of Agriculture, 



Bureau of Entomology, 

 Washington, I). C, July 11, 1906. 

 Sir: I have the honor to transmit herewith the manuscript of a 

 paper entitled ""Habits and Life Histories of some Flies of the Family 

 Tabanidfe" (horseflies), prepared by Prof. James S. Hine, of the Ohio 

 State University, Columbus, Ohio. As is well known, the insects of 

 this family are injurious and anno3'ing to human beings, and especially 

 to horses and cattle, from their bites; but aside from this, and what is 

 of much greater importance from an economic view-point, there is 

 reason to believe that they sometimes act as agents in the transmission 

 of infectious diseases. Every contribution to a knowledge of their 

 habits and life histories is, therefore, of especial value. The present 

 paper embodies the results of original investigations begun l)y Pro- 

 fessor Hine during the summer of 1904 while a special field agent of 

 this Bureau, and I recommend its publication as Part H of Technical 

 Series bulletin No. 12. 



Respectfully, L. O. Howard, 



Chief of Bureau. 

 Hon. James Wilson, 



Secretary of Agricnlture. 



