Vol. XXXI 
AUGUST 15,1925 
JOURNAL OF 
RESEARCH 
No. 4 
CONTENTS 
Steam and Chemical Soil Disinfection with Special Reference to Potato Wart - 
N. REX HUNT, F. G. O’DONNELL, and RUSH P. MARSHALL 
Page 
301 
Nutritive Value of Wheat: I.—Effect of Variation of Sodium in a Wheat Ration 
GEORGE A. OLSON and J. L. ST. JOHN 
363 
An Approximate Method of Calculating Coefficients of Inbreeding and Relationship 
from Livestock Pedigrees - - - - - - - - - 377 
SEWALL WRIGHT and HUGH C. McPHEE 
Further Studies on Isoelectric Points for Plant Tissue - 
WILLIAM J. ROBBINS and IRL T. SCOTT 
385 
PUBLISHED BY AUTHORITY OF THE SECRETARY OF AGRICULTURE 
WITH THE COOPERATION OF THE ASSOCIATION 
OF LAND-GRANT COLLEGES * 
WASHINGTON 
GOVERNMENT PRINTING OFFICE 
1925 
