SPIRILLUM CHOLERA ASIATICS. 575 



the breaking of waves in a harbor, on water-wheels, 

 etc., or in moist wash of cholera patients. 



The cholera bacillus is also injuriously affected by the 

 abundant growth of saprophytic bacteria. It is true 

 that when associated with other bacteria, if present in 

 large numbers, and if the conditions for their develop- 

 ment are particularly favorable, the cholera bacillus 

 may at first gain the upper hand, as in the moist linen 

 of cholera patients, or in soil impregnated with chol- 

 era dejecta; but later, after two or three days, even in 

 such cases, the bacilli die off and other bacteria gradu- 

 ally take their place. Thus Koch found that the fluid 

 contents of privies twenty-four hours after the introduc- 

 tion of comma bacilli no longer contained the living 

 organisms; in Berlin canal-water they were not demon- 

 strable for more than six to seven days, as a rule. In 

 the dejecta of cholera patients they were found usually 

 only for a few days (one to three days), though rarely 

 they have been observed for twenty to thirty days, and 

 on one occasion for one hundred and twenty days. In 

 unsterilized water they may also retain their vitality for 

 a relatively long time ; thus in stagnant well-water they 

 have been found for eighteen days, and in an aquarium 

 containing plants and fishes, the water of which was 

 inoculated with cholera germs, they were isolated sev- 

 eral months later from the mud at the bottom. In 

 running river-water, however, they have not been ob- 

 served for over six to eight days. Even in cultures the 

 comma bacillus is one of the shorter-lived bacteria. 

 They have been observed, however, in pure bouillon 

 cultures for three to four months, and in agar cul- 

 tures for six months, and occasionally in one-year- 

 old cultures when they were protected from desicca- 



