An annually recurring disease among chinook salmмом (Oncorhynchus tahawytscha) FINGERLINGs at the National Fish Hatchery at Coleman, California, was reported by Ross, Pelnar, and Rucker (1960). They presented results of experimental investigation of the disease which established that the etiologic agent was filterable, highly virulent, and resistant to antibiotics and some of the more common chemicals, and that it was apparently not transmitted in salmon product-used as food, as was shown for a virus disease of sockeye salmon (O. merka) by Guenther, watson, and Rucker (T559). Also, Ross and his co-workers (1960) indicated a relation between temperature and incidence of the disease, and speculated on the possibility of the agent's being a virus.