Recent wars have crystallized interest in the bacteriology of traumatic wounds. The literature which accumulated from the first world war alone was enormous. Because of the limited methods of cultivation and identification of bacteria in use then, many of these studies were not entirely satisfactory. However, they showed the frequency with which the anaerobic bacteria of gas gangrene could be cultivated from war wounds. As a result of the intensive study of Fleming, Wright, Henry, Weinberg and Sequin, and others, several fundamental concepts were developed. Wounds received in combat usually were grossly contaminated and all became infected if untreated. The organisms found in wounds were roughly divided into three groups: (1) sporulating microbes of fecal origin, (2) nonsporulating microbes of fecal origin and (3) pyogenic cocci. The first group consisted chiefly of gas producing bacteria, such as Clostridium welchi (perfringens), Clostridium oedematis maligni, Clostridium histolyticus, Clostridium sporogenes, Clostridium fallax, Clostridium