JOURNAL OF 



AGRICULTURAL 



RESEARCH 



Volume XIII 



APRIL I— JUNE 24, 1 91 8 



LIBRARY 

 NEW YORK 

 BOlAMCAL 



OAKDBN 



PUBLISHED BY AUTHORITY OF THE SECRETARY OF AGRICULTURE 



WITH THE COOPERATION OF THE ASSOCIATION OF AMERICAN 



AGRICULTURAL COLLEGES AND EXPERIMENT STATIONS 



WASHINGTON, D. C. 



