LETTER OF TRANSMITTAL 



U. S. Department of Agriculture, 



Bureau of Plant Industry, 



Office of the Chief, 

 Washington, D. 0., May 27 , 1908. 

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

 publication as Bulletin No. 134 of the series of this Bureau the accom- 

 panying technical paper entitled "The Influence of a Mixture of 

 Soluble Salts, Principally Sodium Chlorid, upon the Leaf Structure 

 and Transpiration of Wheat, Oats, and Barley," by Mr. L. L. Harter. 

 This paper has been submitted with a view to publication by Mr. 

 T. H. Kearney, Physiologist in Charge of Alkali and Drought Resist- 

 ant Plant Breeding Investigations. 



The investigations here described help to explain the physiological 

 effects of alkali salts upon plants and hence to throw light upon the 

 problem of what constitutes alkali resistance. The solution of this 

 problem is of great importance in connection with the work of secur- 

 ing useful crop plants for growing in alkali soils. 

 Respectfully, 



B. T. Galloway, 



Chief of Bureau. 

 Hon. James Wilson, 



Secretary of Agriculture. 



134 Q 



