BACTERIUM.

The article offers information on the discovery of Pierce's disease bacterium in 1974 which could destroy grapevines (Vitis vinifera cv) in California. Topics discussed include the disease has been studied with the belief that it was caused by a virus, a study reports on the isolation of a rod-shaped, gram-positive bacterium from disease-spreading leafhopper (Draeculacephala minerva), and experiments have showed that a gram-positive bacterium is the cause of the disease in grapevines.