LETTER OF TRANSMITTAL. 



U. S. Department of Agriculture, 



Bureau or Plant Industry, 



Office of the Chief, 

 Washington, D. C, April 15, 1911. 

 Sir : I have the honor to transmit herewith a paper entitled " Rela- 

 tion of Drought to Weevil Resistance in Cotton," by Mr. O. F. Cook, 

 of this Bureau, and to recommend its publication as Bulletin No. 

 220 of the Bureau series. 



It has been ascertained that dry weather gives a distinct advantage 

 in the production of cotton in the presence of the boll weevil. This 

 relation is being taken into account in improving varieties and cul- 

 tural methods in the direction of weevil resistance. The present re- 

 port shows that several biological factors must be considered in the 

 study of the practical problem of securing a rapid, uninterrupted 

 development of the crop. 



Respectfully, \Vm. A. Taylor, 



Acting Chief of Bureau. 

 Hon. James Wilson, 



Secretary of Agriculture. 



220 S 



