Fatal shock was produced in rats following release of tourniquets applied to one hind extremity for 5 hrs. Anaerobic and aerobic cultures of muscle from the hind limb after death were usually sterile. Organisms of the gas gangrene group were not obtained in any instance. Pre-treatment with sulfadiazine, penicillin, or gas gangrene antitoxin did not influence the development of shock, mortality, or time of survival.