328 BACTERIOLOGY. 



and Tizzoni and Cattani' in both the blood and the 

 gall-^bladder. 



The cholera spirillum is a facultative parasite ; that 

 is to say, it apparently finds in certain portions of the 

 world, particularly in those countries in which Asiatic 

 cholera is endemic, conditions that are not entirely un- 

 favorable to its development outside of the body. This 

 has been found to be the fact not only by Koch, who 

 detected the presence of the organism in the water-tanks 

 in India, but by many other observers who have suc- 

 ceeded in demonstrating its growth under conditions not 

 embraced in the ordinary methods that are employed 

 for the cultivation of bacteria. 



The results of experiments having for their object 

 the determination of the length of time during which 

 this organism may retain its vitality in water are con- 

 spicuous for their irregularity. In the transactions ot 

 the congress in Berlin, for the discussion of the cholera 

 question, it is stated, in connection with this point, 

 that the experiments made with tank-water in India 

 sometimes resulted in demonstrating the multiplication 

 of the organisms introduced into it, while in other cases 

 they died very quickly. 



On February 8, 1884, comma bacilli were found in 

 the tank at Saheb-Began, in Calcutta, and it was pos- 

 sible to demonstrate them in a living condition up to 

 February 23d. 



Koch states that in ordinary spring-water or well- 

 water the organisms retained their vitality for thirty 

 days, whereas in the canal-water (sewage) of Berlin they 

 died after six or seven days ; but if this latter were mixed 

 with fecal matters, the organisms retained their vitality 



1 Centralblatt f. die med. Wlssenschaften, 1886, No. 43. 



