II. Anaerobic, aerotolerant (grow customarily as anaerobes but are able to produce scant, sometimes atj^pical, growth on aerobic agar slants). Cellulose not typically fermented. Distinctive pigments not characteristically produced. A. Central or eccentric to subterminal, ovoid spores. Rods distinctly swollen at sporu- lation. Motile. 1. Gelatin and/or glucose gelatin not liquefied. 89. Clostridium carnis. 2. Gelatin and/or glucose-gelatin liquefied. a. Carbohydrates not fermented. 90. Clostridium histolyticutn. aa. Carbohydrates fermented. 91. Clostridiurn lacunarurri. B. Terminal, distinctly ovoid to ellipsoid spores. Rods distinctly swollen at sporulation. Motile. 1. Gelatin and/or glucose-gelatin not liquefied. 92. Clostridium tertium. 2. Gelatin liquefied. 93. Clostridium peciinovorum. 1. Clostridium butyricum Prazmowski, 1880. (Untersuchungen liber die Entwickel- ungsgeschichte und Fermentwirkung einiger Bacterien-Arten, Inaug. Diss., Leipzig, 1880, 23.) bu.ty'ri.cum. Gr. noun butyrum butter; M.L. adj. hutyricus relating to butter; M.L. noun acidum butyricum butyric acid. Original description supplemented by material taken from Adamson (Jour. Path, and Bact., 22, 1919, 371) and from Hall (Jour. Inf. Dis., SO, 1922, 467). Straight or slightly curved rods, 0.7 by 5.0 to 7.0 microns, with rounded ends, oc- curring singly, in pairs, in short chains and occasionally in long filaments. Spores are oval and eccentric to subterminal, swelling the cells to clostridial forms. Motile. Gran- ulose-positive in the clostridial stage (blue color with iodine). Gram-positive, becom- ing Gram-negative. Gelatin and glucose-gelatin: No lique- faction. Glucose agar surface colonies (anaerobic) : Circular or slightly irregular, slightly raised, moist, creamy white. Glucose agar deep colonies: Biconvex, dense, yellowish white, entire. Agar frag- mented early by abundant gas. Plain agar slant (anaerobic) : Little or no growth. Plain broth: Little or no growth. Glucose broth: Abundant, diffuse tur- bidity; much gas. Litmus milk: Acid and early coagulation. Litmus is reduced. Stormy fermentation; clot fragmented but not digested. Indole not produced. Acid and gas from xylose, glucose, lactose, sucrose, starch, salicin, esculin and manni- tol. Amygdalin, pectin, cellulose, glycerol and Ca-lactate not fermented. Fermentation products include butyl, ethyl and iso-propjd alcohols, acetone, or- ganic acids, H2 and CO 2 . Nitrites not produced from nitrates. Atmospheric nitrogen is fixed, though less actively than by Closlridixun pasteurianum Winogradsky (Rosenblum and Wilson, Jour. Bact., 57, 1949, 413). Coagulated albumin: No liquefaction. Blood agar: No hemolysis. Blood serum: No liquefaction. Brain medium: No blackening or diges- tion. Anaerobic. Grows well between 30° and 37° C. Not pathogenic for guinea pigs or rabbits. Source: Originally isolated from cheese. Commonly encountered in naturally soured milk, in naturally fermented starchy plant substances and in soil. Habitat: Probably rather widely dis- persed in soils rich in humus. 2. Clostridium butylicum (Beijerinck, 1893) Donker, 1926. {Granulobacter butylicum Beijerinck, Verhandl. d. K. Akad. v. We-
