cream-colored, with a nodular or wrinkled surface and irregular thin margin. Nutrient broth without glycerol: No growth. Dorset's egg, Lowenstein, Petragnani, Woolsey colonies: Similar to those on glyc- erol agar, but growth is more rapid and luxuriant. Variation in colony structure of the hu- man and the bovine species has been de- scribed by several authors, e.g. Petroff et al. (Jour. E.xp. Med., 60, 1934, 515), Birk- haug (Ann. Inst. Past., 57, 1933, 428), Kahn et al. (Jour. Bact., 25, 1933, 157), Uhlenhuth and Sieffert (Zeit. Immun., 59, 1930, 187), Reed and Rice (Canad. Jour. Res., 5, 1931, HI), Smithburn, (Jour. Exp. Med., 63, 1936, 95) and Shaffer (Jour. Path, and Bact., 40, 1935, 107). Several of these authors have found associated variation in cell structure and in virulence, though Boquet (Compt. rend. Soc. Biol., Paris, 103, 1930, 290), Birkhaug (Ann. Inst. Past., 49, 1932, 630) and others have failed to find differences in virulence. Reed and Rice (Jour. Immunol., 23, 1932, 385) found the S form to contain an antigenic substance lacking in the R form. Glycerol broth: After 6 to 8 weeks, thick white to cream-yellow, wrinkled pellicle extending up the sides of the flask; no tur- bidity; granular or scaly deposit. Dubos' tween-albumin broth: Diffuse growth visible in a few days and extensive in 7 to 10 days. In undisturbed cultures growth tends to settle but is readily dis- persed. Virulent strains tend to grow in serpentine, cord-like forms in which the bacilli show a parallel orientation. Avirulent forms show a more uniformly diffuse growth (Dubos and Middlebrook, Amer. Rev. Tu- herc, 56, 1947,334). Glucose, fructose, arabinose and galactose are utilized; sucrose and lactose are not utilized (Merrill, Jour. Bact., W, 1930, 235, based on the examination of one strain). Optimum temperature, 37° C. Optimum pH, between 7.4 and 8.0 (Ishi- mori, Ztschr. f. Hyg., 102, 1924, 329); be- tween pH 6.0 and 6.5 (Dernby and Naslund, Biochem. Zeit., 132, 1922, 392). Pathogenicity: Produces tuberculosis in man, monkey, dog and parrot. Experi- mentally, it is highly pathogenic for guinea pigs but not for rabbits, cats, goats, oxen or domestic fowls. Antigenic structure: By agglutination, absorption of agglutinins and complement fixation, a distinction may be made between the human and bovine species and Mycobac- terium avium, but it has been impossible to distinguish by these means between the two mammalian species (Tullock et al.. Tuber- cle, 6, Oct. -Dec, 1924, 18, 57 and 105; Wilson, Jour. Path, and Bact., 28, 1925, 69; Griffith, Tubercle, 6, May, 1925, 417; Rice and Reed, Jour. Immunol., 23, 1932, 385; Kauffman, Ztschr. f. Hyg., 114, 1932, 121). Tuberculins prepared from the human and the bovine species are ordinarily indistin- guishable in their action, but Lewis and Seibert (Jour. Immunol., 20, 1931, 201) detected a difference by cross anaphylactic reactions. Distinctive characters: Mycobacterium tuberculosis produces generalized tuberculo- sis in experimentally inoculated guinea pigs but not in rabbits, voles or fowls. Mycobac- terium bovis produces generalized tuberculo- sis in guinea pigs, rabbits and voles but not in fowls. Mycobacterium microti produces generalized tuberculosis in voles but not in guinea pigs, rabbits or fowls. Mycobacterium avium produces generalized tuberculosis in fowls but not in guinea pigs or voles. Growth of the human form is enhanced by the addi- tion of glycerol to most media. Growth of the bovine and murine forms is not enhanced by glycerol. The human form generally develops a creamy to yellow or faint red pig- ment especially on media containing serum; the bovine and murine forms are not pig- mented. Comments: Griffith (Lancet, 1, 1916-17, 721; Jour. Path, and Bact., 21, 1924, 54) has found aberrant mammalian types, particu- larly in skin lesions of both man and ox, which are, in certain characteristics, inter- mediate between the human and the bovine species. He finds no evidence, however, that the one species may change into the other. Source : Isolated from tuberculous lesions in man. Habitat: The cause of tuberculosis in man. 9. Mycobacterium bovis Bergey et al.,
