bb. Requires serum or ascitic fluid for growth. Produces a black pigment on blood agar. 11. Bacteroides melaninogeniciis. aa. Gelatin liquefied. b. Attack carbohydrates. 12. Bacteroides ovatus. 13. Bacteroides convexus. bb. Do not attack carbohydrates. 14. Bacteroides coagulans. 15. Bacteroides putredinis. 2. Gas not produced in culture media. a. Gelatin is liquefied. 16. Bacteroides uncatus. 17. Bacteroides tumidus. 18. Bacteroides exiguus. 19. Bacteroides uniformis. 20. Bacteroides vulgatus. 21. Bacteroides distasonis. aa. Gelatin not liquefied. b. Action on cellulose not recorded. 22. Bacteroides capillostis. 23. Bacteroides cylindroides . 19. Bacteroides uniformis. 20. Bacteroides vulgatus. 21. Bacteroides distasonis. bb. Attacks cellulose. 24. Bacteroides succinogenes. aaa. Action on gelatin not recorded. 25. Bacteroides glutinosus. 26. Bacteroides destillationis . B. Encapsulated. Sub-genus Capsularis Prevot {ibid., 290). 1. Requires serum or ascitic fluid for growth. 27. Bacteroides viscosus. 2. Does not require serum or ascitic fluid for growth. 28. Bacteroides variabilis. II. Motile. Sub-genus Zuberella Prevot {loc. cit.). A. Gas produced in culture media. 29. Bacteroides serpens. B. No gas produced in culture media. 30. Bacteroides variegatus.
1. Bacteroides fragilis (Veillon and Gelatin: No liquefaction; small amount Zuber, 1898) Castellani and Chalmers, 1919. of gas. {Bacillus fragilis Veillon and Zuber, Arch. Agar colonies: Small, gray, irregular. Med. Exp. et Anat. Path., 10, 1898, 870; Broth: Turbid. Castellani and Chalmers, Man. Trop. Med., j ., •,, ^.t , ,. o,- ,. •3 I A mm nr;n D • , 7 / ;• u - / Litmus milk: No coagulation. Slight 3rd ed., 1919, 959; Ristella fragihs Prevot, Ann. Inst. Past., 60, 1938, 290 (type species ^'^^^^^^ ^* S^^- of genus Ristella Prevot, loc. cit.).) ^"dole not produced. fra'gi . lis. L. adj . fragilis fragile. Hydrogen sulfide not produced. Rods, with rounded ends, staining more Acid from fructose, maltose, sucrose, deeply at the poles, occurring singly and in galactose, glucose and arabinose. Some pairs. Non-motile. Gram-negative. strains produce acid from lactose (Wein-
