LETrHR OF TRANSMIHAL 



U. S. Department of Agriculture, 

 Division of Vegetable Physiology and PATnoLOGY, 



Washington, 1). C, May 31, 1899. 

 Sir : I have the lionor to transmit herewith a report on the cereal 

 rusts of the United States, prepared by Mr. Mark Alfred Carleton, of 

 this Division. Mr. Carleton has been engaged in an investigation of 

 the diseases of cereals for several years and this report contains, in 

 part, the results of the work. The several species of rusts affecting 

 cereals in the United States are fully described, and the distribution of 

 tbese rusts is given, together with a detailed statement of the results 

 of extensive observations and experiments to determine the rust resist- 

 ance of numerous varieties of wheat and oats. The life history of the 

 rusts themselves has been very fully studied and the facts obtained 

 from this work throw important light on problems connected with the 

 breeding of rust-resistant varieties. In view of the wide distribution 

 and the destructiveness of the rusts and the value of tbe results 

 obtained, I respectfully recommend that the report be published as 

 Bulletin No. 16 of this Division. 



Eespectfully, B. T. Galloway, 



Ch ief of Division. 

 Hon. James Wilson, 



Secretary of Agriculture. 



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