ORGANIZATION OF THE U. S. DEPARTMENT OF AGRICULTURE. 



Secretary of Agriculture Henry C. Wallace . 



Assistant Secretary .■ C. W. Pugsley. 



Director of Scientific Worh E. D. Ball. 



Director of Regulatory Work 



Weather Bureau Charles F. Marvin, Chief. 



Bureau of Agricultural Economics Henry C. Taylor, Chief. 



Bureau of Animal Industry John R. Mohler, Chief. 



Bureau of Plant Industry William A. Taylor, Chief. 



Forest Service W. B. Greeley, Chief. 



Bureau of Chemistry Walter G. Campbell, Acting Chief. 



Bureau of Soils Milton Whitney, Chief. 



Bureau of Entomology L. 0. Howard, CAte/. 



Bureau of Biological Survey E. W. Nelson, Chief. 



Bureau of Public Roads Thomas H. MacDonald, Chief. 



Fixed Nitrogen Research Laboratory F. G. Cottrell, Director. 



Division of Accounts and Disbursements A. Zappone, Chief. 



Division of Publications John L. Cobbs, Jr., Chief. 



Library Claribel E,. Barnett, Librarian. 



States Relations Service A. C. True, Director. 



Federal Horticultural Board C. L. Marlatt, Chairman. 



Insecticide and Fungicide Board J. K. Haywood, Chairman. 



Packers and Stockyards Administration | Chester Morrill, Assistant to the 



Grain Future Trading Act Administration J Secretary. 



Office of the Solicitor R. W. Williams, Solicitor. 



This bulletin is a contribution from — 



Bureau of Soils, Milton Whitney, Chief. 



Division of Chemical Investigations, P. L. Gile, in charge. 

 22 



ADDITIONAL COPIES 



OF THIS PUBLICATION MAY BE PEOCtTRED FROM 



THE StrPERINTENDENT OF DOCUMENTS 



GOVERNMENT PRINTING OFFICE 



WASHINGTON, D. C. 



AT 



5 CENTS PER COPY 

 V 



