Gas gangrene, or "acute putrefaction of tissues in vivo," was, until the World War, a clinical curiosity. During the beginning of the war, by nature of the type of explosives, trench warfare, and heavily manured soils, there was a frightful incidence of anaerobic wound infections with a high mortality. Research work was stimulated in order to find means of combating this serious complication. Much progress was made in methods of detection, observation and treatment of these infections. Radical surgery, supplemented by the use of serums, was finally found to be the most satisfactory method of treatment. Since the war, it has been recognized that anaerobic infections are quite widely distributed in civil practice, but it seems evident that the lessons learned during the war have been forgotten, for such radical measures as unwarranted amputations are still being practiced. The object of this paper is to emphasize the importance of serotherapy