ORGANIZATION OF THE UNITED STATES DEPAETMENT OP 

 AGRICULTURE. 



Secretary of Agriculture Henry C. Watt, ace. 



Assistant Secretary C. W. Ptjgsley, 



Director of Scientific Work E. D. Ball. 



Director of Regulatory Work , 



Weatlur 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, Chief 



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 R. 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 — 



Forest Service W. B. Greeley, Chief. 



Branch of Lands L. F. Kneepp, in charge. 



Bureau of Plant Industry William A. Taylor, Chief. 



Investigations in Forest Pathology Haven Metcalf, in charge. 



36 



ADDITIONAL COPIES 



or THIS PUBLICATION MAY BE PEOCUEED FROM 



THE SUPERINTENDENT OF DOCUMENTS 



GOVERNMENT PRINTING OFFICE 



WASHINGTON, D. C. 



AT 



15 CENTS PER COPY 



V 



