Crude penicillin, produced in the laboratory, has been used to cure crown gall on Bryophyllum. The galls were of the "soft gall" type, produced by hypodermic injection of a pure culture of Agrobacterium tumefaciens. The method of application of the penicillin successfully employed was to puncture the gall in numerous places with a sterile needle, and then wrap it in penicillin-soaked antiseptic cotton, thereafter frequently wetted with crude penicillin. Noteworthy, is the fact that penicillin in this instance apparently destroys a Gram-negative organism.