short chains, tetrads and irregular groups. Non-motile. Not encapsulated. Gram-posi- tive. Growth does not occur on complex ni- trogenous or sugar-containing media to any observable extent in the absence of added glycine; furthermore, ordinary distilled water is frequently toxic to this organism, and glass-distilled water or a 1 :1 mixture of glass-distilled and tap water is recom- mended in the preparation of media. Gelatin: Liquefaction. Agar plate colonies: Circular, up to 0.5 mm in diameter, smooth, entire, convex, opaque, grayish white, butyrous. Growth in fluid medium: Slow but abun- dant growth in peptone yeast extract medium containing 0.3 per cent added glycine; coarsely granular; no odor; no gas. Litmus milk: Partial reduction. Indole not produced. Hydrogen sulfide not produced. Glycine or glycine-containing peptides are fermented. Other amino acids, organic acids and carbohydrates are not utilized. Glycine is decomposed to CO 2 , NH3 and acetic acid; under certain conditions H2 may also be formed in addition to the above products. Nitrites produced from nitrates; nitrites are reduced. Coagulase-negative. Catalase-positive. Anaerobic. Optimum temperature, 37° C. Optimum pH, 7.2; pH range, 6.0 to 8.5. Non-hemolytic. Distinctive characters: Large cell size; distinctive catabolism. The predominant organism in anaerobic enrichment cultures prepared by inoculating mud into 1 per cent glycine in tap water. Source: Isolated from mud in the tidal areas of San Francisco Bay. Habitat: Mud and soil. 10. Peptococcus variabilis (Foubert and Douglas, 1948) Douglas, coinb. nov. {Micrococcus variabilis Foubert and Douglas, Jour. Bact., 56, 1948, 25.) va.ri.a'bi.lis. L. adj. variabilis variable. Original description supplemented by ma- terial from Douglas (Jour. Bact., 62, 1951, 517). Spheres, 0.5 to 1.5 microns in diameter, occurring singly, in pairs, tetrads and ir- regular groups. Non-motile. Not encapsu- lated. Gram-positive. Gelatin: Liquefaction. Agar colonies: Circular, 0.5 to 1.0 mm in diameter, smooth, entire, low convex, opaque, grayish white, butyrous. Growth in fluid medium: In peptone yeast extract broth, growth moderately heavy, cloudy; no odor; no visible gas. Growth not enhanced by glucose. Litmus milk: Slight reduction. Indole not produced. Hydrogen sulfide is produced. Cell organisms and growing cultures de- compose glycine to CO2 , NH3 and acetic acid. Other amino acids, purines, lactate and malate not decomposed. No acid pro- duction or growth enhancement by sugars although chemical analyses show that small amounts of glucose are utilized by all strains. Nitrites not produced from nitrates; ni- trites not reduced. Coagulase-negative. Catalase-positive. Anaerobic. Optimum temperature, 37° C. Growth between 25° and 37° C. Optimum pH, 7.0; pH range, 6.5 to 8.5. Non-hemolytic. Distinctive characters: No visible gas production; glycine fermented to CO2 , NH3 and acetic acid; liquefaction of gelatin and variable cell size distinguish this species from Peptococcus anaerohius. Source: Isolated from the female genital tract; also from a normal tonsil and a drain- ing sinus. Habitat: Human sources so far as known. 11. Peptococcus anaerobius (Hamm, 1912) Douglas, comb. nov. (Anaerobic staphylococcus, Jungano, Compt. rend. Soc. Biol., Paris, 59, 1907, 707; Staphylococ- cus anaerobius Hamm, Die puerperale Wun- dinfektion, Berlin, 1912; not Staphylococcus anaerobius Heurlin, Bakt. Unters. d. Keim- gehaltes im Genitalkanale d. fiebernden Wochnerinnen, Helsingfors, 1910, 120;
