394 SUMMARY OF CURRENT RESEARCHES RELATING TO 



& 



germination. The optimum oxygen concentration is that point at 

 which germination most rapidly occurs ; the maximum oxygen concen- 

 tration is the greatest the organism can withstand. The author arranges 

 bacteria into groups according to their behaviour to different oxygen 

 concentrations. For spore germination and growth these cardinal 

 points of oxygen concentration are very similar, but for spore formation 

 there is much variation. Thus, B. mycoides shows an optimum growth 

 and spore germination with a concentration of 70 mg. of oxygen per 

 1000 c.cm., a maximum concentration of 1336 mg. of oxygen, whereas 

 a minimum concentration of 4*3 mg. per 1000 c.cm. is essential. If 

 the spore formation of the same organism is considered, the minimum 

 concentration is 6*8 mg., the optimum 267 mg., and the maximum 

 1336 mg. of oxygen per 1000 c.cm. of surrounding atmosphere. 



Organism of " Phlegmon emphysemateux." * — V. and A. Babes 

 have isolated an organism from the body of a man who had died after 

 an operation for external urethrotomy. Various parts of the body were 

 much distended with gas, and showed necrotic .foci ; microscopic 

 examination showed the presence of a large bacillus in enormous 

 numbers. The bacillus, which measured 3-6 \x by 1 p., was non-motile, 

 and contained varying sized oval formations, corresponding to spores ; 

 when stained by Gram's method it presented a red axial thread, on 

 either side of which is a pink zone limited externally by a broad blue 

 peripheral portion ; the organism is anaerobic, and produces large gas 

 bubbles on glucose agar ; it only grows in the depth of the medium, 

 which is broken up by the gas developed. Inoculation into rabbits 

 caused only a small emphysematous swelling, which disappeared the 

 next day. The authors consider that the organism is identical with 

 that described by Fraenkel as B. phlegmonis emphysematosHs. There 

 appeared to be no doubt that this organism was the cause of the local 

 lesion, and that, being transported to different organs, a fatal general 

 infection was established. 



Anaerobic Flora of the Mouth/j-— G. Repaci has isolated in pure 

 culture from the mouth of a healthy man an organism which morpho- 

 logically and biologically resembles Bacillus fusiformis, which was 

 described by Vincent as occurring in symbiosis with spirilla. The 

 bacillus has pointed ends, and varies in length from 10-5 /x ; it stains 

 by ordinary dyes, but not by Gram's method ; it is non-motile ; it does 

 not form spores ; it is a strict anaerobe. At 37° C. it appears on glucose 

 agar after 18-24 hours, as small round, opaque, grey points ; these 

 increase in size to 2 mm. diameter, and exhibit a central salmon-coloured 

 nucleus surrounded by a grey zone : there is no production of gas, but 

 the media give off a disagreeable odour. The author states that the 

 organism grows on gelatin at 37° C. without causing liquefaction, and 

 without clouding the medium, but forming an abundant deposit ; it 

 ferments glucose, lactose, and dextrose ; it grows in milk, producing 

 acid, but not coagulation ; it produces indol in peptone broth : it is 

 pathogenic for guinea-pigs and mice. 



* C.R. Soc. Biol. Paris, lxvi. (1909) p. 324. t Tom. cit., p. 59G. 



