"A bacterial leafspot disease of the occurs widespread in the Eastern States. It is mostly a disease but occurs occasionally on plants grown out of doors. The organism was isolated from diseased plants received from different sources and the disease reproduced on the leaves of healthy plants. Warm, moist conditions with poor ventilation are necessary for the organism to infect the leaves extensively. Care in regulating the temperature, air, and moisture conditions of the greenhouse and in giving plenty of space to plants grown out of doors will go far toward preventing the appearance of the disease and toward curing it when it is present. All spotted leaves should be removed and destroyed. Very sensitive varieties should be discarded. The name Bacterium pelargoni is suggested for the organism causing the disease."