226 SUMMARY OF CURRENT RESEARCHES RELATING TO 



slightly motile, stains by Gram's method, and forms spores; when 

 grown on gelatin it liquefies the medium. 



B. tartaricum is not a marked nitrogen fixer ; it occurs as short rods, 

 which are not motile, do not stain by Gram's method, do not form 

 spores, and do not liquefy gelatin. 



Cultural Differentiation of Capsulated Bacilli.* — V. K. Russ 

 •examined a number of capsulated bacilli belonging to the four groups 

 of (1) B. lactis aerogenes, (2) B. pneumonia, (3) B. mucosus ozcence, 

 (4) B. scleromatis, in respect to their production of acid and alkaline 

 with carbohydrate media, and their reactions to coloured media of 

 Endo's fuchsin, and Loeffier's green solution. 



The carbohydrates used were dextrose, galactose, lsevulose, lactose, 

 maltose, saccharose, starch, arabinose, dextrin, mannite, dulcite, and 

 erythrite. The tests showed that only B. scleromatis produced alkali, 

 or had no action with lactose ; only B. ozarnce produced acid with 

 erythrite ; that B. aerogenes and B. ozcence both formed acid, whilst 

 B. friedldnderi and B. scleromatis both gave alkaline reaction, or had no 

 effect with dulcite. 



On Endo's lactose fuchsin agar, the aerogenes group behaved as the 

 coli group, producing a deep red colour ; the B. friedldnderi and 

 B. scleromatis behaved as B. typhosus, or had no effect, and with 

 B. ozamce the medium was coloured pink. 



The author gives a table of the results obtained with four solutions 

 of Loeffier's green, and finds that though B. lactis aerogenes has very 

 marked characters with these solutions, the test is not of practical use in 

 differentiating the other three groups. The author also refers to other 

 capsulated organisms not included in the above four groups, and shows 

 in what way they are allied biologically according to the above tests. 

 It appears that B. capsulatus of Pfeiffer, and B. mucosus capsulatus 

 of Fasching, are both indentical with B. lactis aerogenes. 



* Centralbl. Bakt., lte Abt. Orig., xliv. (1907) p. 289. 



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