Abstract
Except for a short time lag in the appearance of symptoms, a graded concentration series of CMU in water produced similar effects on intact plants and on excised tops of tomato and kidney-bean. When applied to roots, CMU had ready access to the vascular system and was quickly carried in the xylem to the tops. Wherever a lethal concentration was reached, the CMU killed the tissues of the leaves. As roots of treated plants lived for some days after the leaves were killed, the foremost toxic action of CMU must have taken place in the leaves.