Vol. XX DECEMBER 1; 1920 Uo. 5 



JOURNAL OP 



AGRICULTURAL, 



RESEARCH 



CONTENTS 



Page 



Permanence of Differences in the Plots of an Experi- 

 mental Field - . - - - - - - - 335 



J. ARTHUR HARRIS and C. S. SCOFIELD 

 (Contribution from Bureau of Plant Industry) 



Some Changes in Florida Grapefruit in Storage - - 357 



LON A. HAWKINS and J. R. MAGNESS 



(Contribution from Bureau of Plant Industry) 



A Bacteriological Study of Canned Ripe Olives - - 375 



STEWART A. KOSER 



( Contribution from Bureau of Chemistry ) 



Relation of the Soil Solution to the Soil Extract - - 381 



D. R. HOAGLAND, J. C. MARTIN, and G. R. STEWART 



(Contribution from California Agricultural Experiment Station ) 



Effect of Season and Crop Growth on the Physical State 



of the Soil - -397 



D. R. HOAGLAND and J. C. MARTIN 



(Contribution from California Agricultural Experiment Station) 



PUBLISHED BY AUTHORITY OF THE SECRETARY OF AGRICULTURE, 



WITH THE COOPERATION OF THE ASSOCIATION OF 



LAND-GRANT COLLEGES 



WASHINGTON, D. C. 



WASHINQTOM : GOVERNMENT PRINTING OFFIOE : IMO 



