LETTER OF TRANSMITTAL 



U. S. Department of Agriculture, 



Bureau of Plant Industry, 



Office of the Chief, 



Washington, D. C, December 18, 1909. 



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

 History and Distribution of Sorghum," by Mr. Carleton R. Ball, 

 Agronomist in Charge of Grain-Sorghum Investigations, and rec- 

 ommend its publication as Bulletin No. 175 of the series of this 

 Bureau. 



The facts stated in the paper have been developed in connection 

 with a study of the agronomic adaptations of over 1,000 varieties of 

 domestic and foreign sorghums. Data concerning the geographical 

 distribution of the sorghum plant and the leading types which are 

 found in different regions of the earth are here presented for the 

 first time. Sorghums have been very extensively used as human food 

 in Africa and the Orient for more than twenty-five centuries. Some 

 of them are now important grain and forage crops in large areas of 

 the western United States, and have been found adapted to a much 

 wider range of climatic and soil conditions than was formerly 

 thought possible. A knowledge of their distribution and adapta- 

 tions in their native lands will be of value to all agronomic workers 

 and others concerned in the improvement of these crops. 



The author wishes to acknowledge his obligation to Miss R. M. 

 Kolck for assistance in the translation of the Latin works; to Miss 

 A. R. Knapp for the translation of the Italian article by Arduino; 

 and to Miss M. F. Warner for aid in securing and citing many old 

 and rare botanical works. 



Respectfully, B. T. Galloway, 



Chief of Bureau. 



Hon. James Wilson, 



Secretary of AgHculture. 



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