MICROSPIRA COMMA. 493 



C. ; but it is slower, the maximum development of the 

 cholera organisms being reached at about the fifteenth 

 hour, after which time they were outnumbered by the 

 ordinary saprophytes present. 



From the foregoing it would seem that the vitality of 

 microspira comma in milk depends largely upon the 

 reaction ; the more quickly the milk becomes sour the 

 more quickly does the organism become inert ; while the 

 longer the milk retains its neutral, or only very slightly 

 acid, reaction, the longer do the cholera organisms that 

 may be present in it retain their power of multiplication. 



According to Laser, 1 the cholera organism retains its 

 vitality in butter for about seven days ; it is therefore pos- 

 sible for the disease to be contracted by the use of butter 

 that has in any way been in contact with cholera material. 



In regard to the antagonism between the microspira 

 comma and other organisms with which it may come 

 in contact, the experiments of Kitasato 2 led him to 

 conclude that no organism has been found which, 

 when growing in the same culture-medium with it, 

 possessed the power of depriving it of vitality within 

 a short time. On the other hand, the experiments 

 showed that there were quite a number of other organ- 

 isms the development of which was checked, and in 

 some cases their vitality was completely destroyed, when 

 growing in the same medium, with the microspira comma. 



From this it woujd appear that the disappearance of 

 the microspira comma from mixed cultures and from 

 the evacuations in the short time mentioned is due more 

 to unfavorable nutritive conditions than to the direct 

 action of the other organisms present. 



1 Laser : Zeitschrift fur Hygiene, Bd. x. S. 513. 

 'Kitasato: Ibid., Bd. vi. S. 1. 



