Vol. XIX 



JULY 1, 1920 No. 1 



JOURNAL OF 



AGRICULTURAL 



RESEARCH 



CONXKNTS 



Page 



Practical Universality of Field Heterogeneity as a Factor 



Influencing Plot Yields - - 279 



J. ARTHUR HARRIS 



( Contribution from Bureau of Plant Industry) 



Transmission of the Mosaic Disease of Irisli Potatoes - 315 

 E. S. SCHULTZ and DONALD FOLSOM 



( Contribution from Bureau of Plant Industry and 

 Maine Agricultural Experiment Station ) 



PUBUSHED BY AUTHORITY OF THE SECRETARY OF AGRICULTURE, 



WITH THE COOPERATION OF THE ASSOQATION OF 



LAND-GRANT COLLEGES 



WASHINGTON, D. C. 



WA»HIMaTON ; OOVEHNMEHT PBINTINQ OFFICE : l»»» 



