translation. Gram-negative. Stain with more or less distinct granules which may become Gram-positive. Surface colonies are butyrous, round, entire and, especially in early cultiva- tion, may appear as clouded, white flecks in a water-clear medium. Glucose is usually fer- mented. Possess fastidious nutrient requirements for growth. Anaerobic to microaero- philic. Limited pathogenicity for man and laboratory animals. Found in the buccal cavity and various infections of man. Although it is now known that the genus Fusiformis Hoelling is based on a type species, Fusiformis termitidis Hoelling, which presumably belongs in the genus Cytophaga Wino- gradsky, some bacteriologists continue to use this generic name for the anaerobic, fusiform bacteria found in the human mouth. The latter organisms are closelj^ related to the anaero- bic. Gram-negative species found in the human intestine, and the generic name Fiisohade- rium Knorr appears to be the legitimate name for this group. The type species is Fusobaclerium fusiforme (Veillon and Zuber) Hoffman. Key to the species of genus Fusobacterium. I. Long rods, attaining a length of 8 to 16 microns. A. Acid from maltose. B. No acid from maltose. 1. Fusobacterium fusiforme. 2. Fusobacterium polymorphum. II. Short rods, usually not exceeding 4 microns in length. A. Motile. 3. Fusobacterium praeacidum. B. Non-motile. 1. Milk unchanged. a. Stubby, spindle-shaped cells. 4. Fusobacterium nucleatum. aa. Slender, pointed cells. 5. Fusobacterium vescum. 2. Milk acidified and coagulated. 6. Fusobacterium biacutum. 1. Fusobacterium fusiforme (Veillon and Zuber, 1898) Hoffman, comb. nov. (Ba- cille de la pourriture d'hopital, Vincent, Ann. Inst. Past., 10, 1896, 495; Bacillus fusiformis Veillon and Zuber, Arch, de M^d. Exp6r. et Anat. Path. (Paris), ser 1, 10, 1898, 540; not Bacillus fusiformis Gottheil, Cent. f. Bakt., II Abt., 7, 1901, 724; Le ba- cille fusiforme, Vincent, op. cit., IS, 1899, 613; Bacillus hastilis Seitz, Ztschr. f. Hyg., SO, 1899, 47; Corynebacterium fusiforme Leh- mann and Neumann, Bakt. Diag., 4 Aufl., 2, 1907, 529; Fusiformis dentium Hoelling, Arch. f. Protistenk., 19, 1910, 239; Fuso- bacterium plauti-vincenti Knorr, Cent. f. Bakt., I Abt., Orig., 89, 1923, 5; Fusiformis fusiformis Topley and Wilson, Princip. of Bact. and Immun., 1st ed., 1931, 300.) fu.si.for'mis. L. noun fusus a spindle; L. noun forma shape; M.L. adj. fusiformis spindle-shaped. Original description supplemented by material taken from Hine and Berry (Jour. Bact., S4, 1937, 523). Straight or slightly curved rods, 0.5 to 1.0 by 8.0 to 16.0 microns, occurring in pairs with blunt ends together and outer ends pointed, sometimes in short, curved chains or long spirillum-like threads. Granules present. Non-motile. Gram-negative. No gas or odor produced. Gelatin: No growth. Colonies: Circular, 1 to 3 mm in diameter, shaped like a low cone, surface resembles hammered copper or may be wrinkled and pitted; regular edge. Plain agar: No growth. Meat infusion agar: Growth. Serum agar shake culture: After 36 hours, colonies spherical, up to 0.5 mm in diameter, thin, yellowish brown. Serum agar plate: Matted growth. Me-
