swelling the cells. Motile by means of peri- trichous flagella. Gram-positive. Gelatin: No liquefaction. Gelatin is liquefied (Hall, Jour. Inf. Dis., 30, 1922, 501). Agar surface colonies (anaerobic): Small, flat, irregularly circular, translucent, cre- nated. Agar deep colonies: Small, opaque, irregu- lar; not woolly or branched. Agar slant (anaerobic) : Grayish, translu- cent growth. Broth: Turbid. Litmus milk: Unchanged or occasionally slight reduction of litmus. Indole not produced. Acid and gas from glucose and maltose. Fructose, galactose, lactose, sucrose, sali- cin, inulin, mannitol and glycerol not fer- mented. Nitrates rapidly reduced; nitrites absent (Reed, Jour. Bact., U, 1942, 425). Atmospheric nitrogen is fi.xed, though not as actively as by Clostridium pasteurianum Winogradsky (Rosenblum and Wilson, Jour. Bact., 57, 1949, 413). Coagulated albumin: No liquefaction. Blood serum: No liquefaction. Brain medium: No blackening or diges- tion. Egg-meat medium: Slight gas production in 48 hours. White crystals are deposited. Anaerobic. Grows at 30° and at 37° C. Not pathogenic for guinea pigs or rabbits. Source: Isolated from war wounds and from soil. Habitat: Not determined. Probably rather common in soil. 66. Clostridium putrefaciens (Mc- Bryde, 1911) Sturges and Drake, 1927. (Bacillus putrefaciens McBryde, U.S.D.A., Bur. An. Ind., Bull. 132, 1911, 6; Sturges and Drake, Jour. Bact., U, 1927, 175.) pu.tre.fa'ci.ens. L. part. adj. putrefaciens putrefying. Rods, 0.5 to 0.7 by 3.0 to 15.0 microns, with rounded ends, occurring singly, in pairs and in chains and filaments. Spores spherical, terminal, swelling the cells. Non-motile. Gram-positive. Gelatin: Liquefaction. Agar surface colonies (anaerobic) : Small, filamentous. Agar slant (anaerobic) : Scanty, white, beaded, glistening growth. Broth: Moderately turbid; heavy, floccu- lent sediment. Litmus milk: Rennet coagulation; pep- tonized. Litmus reduced. Indole not produced. Hydrogen sulfide produced in slight amounts. Acid and gas from glucose. Lactose, su- crose, maltose and starch not fermented. Nitrites not produced from nitrates. Coagulated albumin: Liquefaction. Blood serum: Liquefaction. Brain medium: Blackening and slow di- gestion. Minced pork medium: Slight disintegra- tion; sour, putrefactive odor. Anaerobic. Temperature relations: Optimum, be- tween 20° and 25° C. Slow growth at 0° C; no visible growth at 37° C. Not pathogenic. Source: Isolated from muscle tissues of hogs at slaughter. Habitat: Not determined. 67. Clostridium thermoaceticum Fon- taine et al., 1942. (Fontaine, Peterson, McCoy, Johnson and Ritter, Jour. Bact., 43, 1942, 705.) ther.mo.a.ce'ti.cum. Gr. adj. thermus hot; M.L. noun acidurn aceticum acetic acid; M.L. adj. thermoaceticus (probably intended to mean) producing acetic acid under ther- mophilic conditions. Rods, 0.4 by 2.8 microns. Spores terminal, very nearly round, slightly swelling the cell. Gram-positive. Gelatin: No liquefaction. Agar colonies: Circular, smooth, opaque. Litmus milk: Slight reduction of litmus. Glucose, fructose and xylose are readily fermented. Lesser fermentation of galac- tose, mannose, d-arabinose, d-lactic acid, gluconic acid and esculin. Nitrites produced from nitrates. Coagulated egg albumin: Not attacked. Brain medium: Not attacked. Anaerobic. Temperature relations: Optimum, be-
