1019] VETl.KIXAKY M1CDICINE. 677 



antibodies against the streptococcus are produced In the injected animals. 



Other experiments arc reported Bhowing the availability of subcutaneous I u 



latlons of l'at antigens for the production of Immunity in man and the power of 

 an Immune serum to precipitate with the Individual components <<!' a fat 

 antigen complex. 



In conclusion, the author stales that "the fails brought OUt in the work on 



the functions of antigenic fats in Immunity lead one to believe that such anti- 

 gens are destined to play an Important pari not only in active Immunization of 



animals and man as a prophylactic measure hut also in the treatment of Infec- 

 tions. They have to commend them their purity, the dosage by weight, the 



absence of toxicity, and the ease and safety of either subcutaneous or intra- 

 venous administration." 



The use of the final hydrogen-ion concentration in differentiation of 

 Streptococcus hemolyticus of human and bovine types, ( >. T. Avkky and 

 G. E. (Vi.i.kn (Jour. Expt. Med., 29 (1919), No. 2, pp. ..'/.". 284, .""<• 8).—- Studies 

 are reported which show that there is a distinct ami constant difference in 

 the linal 11-iou concentration of Streptococcus hemolyticus from human and 

 bovine sources under like conditions of growth. Of 124 strains of .v. hemolyticus 

 from known human origin, 1 Hi reached a linal II-ion concent rat ion of from 

 pll 5 to 5.3. Only 8 reached a pH more acid than 5 and none more; acid than 

 pll 4.8. Of 45 strains of B. hemolyticus from bovine sources, including 26 

 si rains isolated from milk and the udder of cows and 1!) from cream cheese, 40 

 reached a linal II-ion concentration of pll 4.3 to 4.5. Of the remaining 5 which 

 reached a pll of 5 to 5.2, 2 were of known human type, and ;'> of uncertain 

 diagnosis. In the application of this method to the determination of the type 

 of 8. hemolyticus the following procedure has been adopted: 



The strain to he tested is grown in test tubes containing 5 cc. of 1 per cent 

 dextrose broth. After the maximum growth has been reached, generally within 

 24 to 48 hours but depending upon the size of the inoculum and the suitability 

 of the medium, the culture fluid is diluted with 10 per cent of distilled water, 

 and 1 drop of 0.1 per cent alcoholic solution of methyl red is added. A faint 

 salmon-pink color indicates the human type and a decided red the bovine type 

 of streptococcus. This color difference is said to be so marked as to make a 

 comparison with standard solutions unnecessary. 



Horse blood or sheep blood dextrose agar plates as substitutes for human 

 blood dextrose agar plates for the culture of pathogenic anaerobes, J. Xkiss- 

 Xjb (Deut. Med. Wchnachr., M (1918), No. 81,. p. .'"/.-).— The author has found 

 that horse blood or sheep blood can be used In place of human blood in the 

 dextrose-blood-agar medium employed for the culture of pathogenic anaerobes. 

 The organisms show the same characteristics as on the media usually employed. 



A preliminary note on the preparation of culture media suitable for the 

 growth of organisms used in vaccines, I >. Nonius (Indian dour. Mid. Research, 

 6 (1018), No. 2, pp. 174-189). — Various types of culture media have heen pre- 

 pared with a view to the determination of their nutritive value as regards the 

 growth of Bacillitu typhosus for vaccine purposes. 



Of the various meat media at present in use, those prepared by means of a 

 tryptic digestion appear to be more nutritive than an ordinary beef peptone 

 medium or than those prepared by acid hydrolysis. The addition of nut rose or 

 casein appeared to have no influence on growth except with a particularly non- 

 nutritive medium. The addition, however, of a comparatively small amount of 

 hydrolyzed nutrose to a poor medium greatly increased its nutritive power. 

 Media obtained by the tryptic hydrolysis of nutrose, peanut press cake, and 

 casein gave material equal in nutritive value to that obtained from meat. (A>u- 



