PLATE i 
A. —Com seedlings 6 weeks old grown in quartz sand mixed with glauconite from 
Courtland greensand at the rate of io tons per acre. 
B. —Com seedlings 6 weeks old grown in quartz sand mixed with Courtland green¬ 
sand from which most of the glauconite had been removed, at the rate of io tons per 
acre. 
