SCHREINER & SKINNER: EFFECT OF GUANIDIN ON PLANTS 545 
Fic. 4. Harmful effect of guanidin on cowpeas; no. 1 and 2 without guanidin, 
no. 3 and 4 with guanidin. 
tions of 25 parts per million. With all these plants the harmful 
effect on growth is clearly shown and the same general physiolog- 
ical action was manifested as in the case of wheat. 
Fic. 5. Harmful effect of guanidin on potatoes; no. 1 without guanidin, no. 2 
with guanidin, 
INFLUENCE OF ORGANIC NITROGENOUS COMPOUNDS 
In regard to the influence of nitrate in increasing the harmful- 
hess of guanidin some further studies were made which indicate 
