20 L. A. JULIANELLE 



In making our determination, the medium contained 1% peptone, 

 0.5% K 2 HPO 4 and \% KNO 3 . The cultures were incubated for one 

 week at 37 C, and the presence of nitrates was determined by the 

 sulphanilic acid a naphthalamine method. All the strains except A 

 were able to reduce nitrates. 



Formation of Indol. In a survey of the literature of indol production by 

 staphylococci, 3 references have been found of a positive nature. Emmerling 38 

 described the production of indol afer 14 days' cultivation under anaerobic 

 conditions on an egg white medium. Tissier and Martelly* 9 reported positive 

 indol by a culture of Staphylococcus albus isolated from meat, and cultivated 

 in a fibrin medium. Distaso 4 " isolated an atypical Staphylococcus which was 

 an obligate anaerobe and showed inability to attack any sugar, but which was 

 capable of forming indol. The results of the first two are questionable on 

 account of the technic employed, while the third case is concerned with an 

 atypical organism. On the other hand, negative indol production is reported 

 by Buard, 41 Seltzer, 42 Dobrowski, 48 Distaso, 44 Zipfel, 45 Herzfeld and Klinger, 46 

 Winslow, Rothberg, and Parsons, 33 and Bayne-Jones and Zimmiger. 47 



Our tests were made by cultivating in a medium of \% peptone and 

 0.5% K 2 HPO 4 at 37 C. Tests for the presence of indol were made 

 on the first, third, fifth, seventh and tenth day after incubation by the 

 para-dimethyl-amido-benzald-benzaldehyde method. All tests were 

 negative. 



Action on Milk. Table 10 gives the reaction of each strain in 

 litmus milk. It will be seen that after 10 days' incubation at 37 C., 

 one strain shows no apparent change in reaction, 11 strains show acid 

 production, and 8 strains show acid with coagulation and liquefaction. 

 The P H values in lactose broth has been placed alongside the milk reac- 

 tions. As was expected, the reaction coincides. 



Liquefaction of Gelatin. In determining gelatin liquefaction, an 

 effort was made toward a quantitative study. The technic employed 

 was to inoculate gelatin tubes with 0.1 c c of a 24-hour broth culture 

 (diluted if necessary to insure an even turbidity). The amount of 

 gelatin liquefied was measured by determining the number of c c from 

 a mark drawn at the original level of the gelatin to the level of the 



88 Berlin der Deutsch. Chem. Gessellsch., 1896, 29, p. 27.21. 



89 Ann. de 1'Inst. Pasteur., 1910, 24, p. 865. 



40 Centralbl. f. Bakteriol., I, O., 1912, 62, p. 433. 



41 Compt. rend. Soc. de biol., 1908, 65, p. 158. 



42 Centralbl. f. Bakteriol., I, O., 1909, 51, p. 465. 



43 Ann. de 1'Inst. Pasteur., 1910, 24, p. 595. 



44 Centralbl. f. Bakteriol., I, O., 1911, 59, p. 10? 



46 Ibid., 1913, 67, p. 572. 

 4B Ibid., 1915, 76, p. 1. 



47 Bull. Johns Hopkins Hosp., 1921, 32, p. 299. 



