426 MICRO-ORGANISMS AND DISEASE [chap. 



nutrient gelatine kept for a few days at 20° C, continued to 

 grow slowly but steadily after the gelatine was then kept at 

 15-16° C. Comma bacilli gradually die off if nutri- 

 ment is insufficient, e.g., in water ; they are gradually killed 

 in faecal matter (Kitasato) ; and they do not grow well when 

 oxygen is absent from the culture (Koch). 



Comma bacilli obtained from typical cases of Asiatic 

 cholera grow well in milk at 37" C, they herein rapidly 

 multiply and in some cases cause no visible change, while 

 in others they cause coagulation of the milk ; but also in 

 regard to this latter phenomenon there exist considerable 

 differences, for while some varieties cause coagulation after 

 five or six days others take several weeks. Most varieties 

 of cholera vibrios (derived from cases of Asiatic cholera) 

 produce alkali in culture media {e.g., in Petruschki's 

 neutral whey), but some varieties undoubtedly produce 

 slight acid. Another difference noticed between the 

 vibrios derived from different cases of Asiatic cholera refers 

 to their action when injected subcutaneously into guinea- 

 pigs. Koch 1 had already succeeded in producing acute 

 septicsemic infection of mice by intraperitoneal injection of 

 large doses {see later), with rapid multiplication of the 

 vibrios in the blood ; Ferran and D. D. Cunningham ^ 

 have succeeded in producing septicaemic infection by sub- 

 cutaneous injection into guinea pigs ; after death the blood, 

 the smeary exudation on the serous covering of the intestine 

 and the intestinal contents containing an abundance of 

 the cholera vibrios. I have produced this effect both with 

 gelatine cultures of cholera vibrios as also of Finkler's 

 vibrios, using o'5-2 cc. of the liquefied culture per guinea- 



^ Conferenz zur Erorterung d. Cholerafrage, Berl. Jdin. Woch. 31, 

 1884. 

 ^ Scientific Memoirs, Calcutta, 1S91. 



