LETTER OF TRANSMITTAL. 



U. S. Department of Agriculture, 



Bureau of Plant Industry, 



Office of the Chief, 

 Washington, D. C, July 15, 1907. 

 Sir: I have the honor to transmit herewith and to recommend for 

 publication as Bulletin No. 113 of the series of this Bureau the accom- 

 panying technical paper, entitled "The Comparative Tolerance of 

 Various Plants for the Salts Common in Alkali Soils," by T. H. 

 Kearney and L. L. Harter. 



The results of this work show clearly that different genera and 

 species of plants differ greatly in their power of resistance to a given 

 mixture of alkali salts and that marked differences in resistance also 

 exist between different individuals of the same strain or variety, 

 proving, therefore, that there is a good opportunity for increasing 

 this quality by the artificial selection of resistant strains. The work 

 also shows clearly that a strain made resistant to one combination of 

 salts may not be resistant to another combination. The results are 

 therefore important to those engaged in the selection and improvement 

 of crops for alkali soils. 



Respectfully, B. T. Galloway, 



Chief of Bureau. 

 Hon. James Wilson, 



Secretary of Agriculture. 



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