XX] ANTAGONISM AMONGST BACTERIA 531 



his cultures, but the impurity of his cultures (Kitt), and 

 likewise the attenuated condition of the culture fluids that 

 Pasteur used for protective inoculations against swine ery- 

 sipelas was probably caused by the impurity of the culture 

 fluid (Schiitz), there being present in Pasteur's fluid, be- 

 sides the true bacillus of swine erysipelas, a contaminating 

 micrococcus. 



Watson Cheyne, von Emmerich {Archiv. f. Hygiene, vi. 

 1887), and others showed that the streptococcus erysipelatos 

 possesses such an attenuating influence on the bacillus an- 

 thracis, for by inoculating simultaneously pure cultures of 

 the two microbes into rabbits they were able to show that 

 the bacillus anthracis was unable to produce fatal anthrax, 

 though when separately inoculated they exerted their full 

 virulence. It depends, however, to a considerable degree 

 how much of the one and how much of the other microbe 

 is injected in order to produce this inhibitory effect, for if too 

 little of the streptococcus be injected the bacillus anthracis 

 will exert its full virulence, or vice versa. This whole subject 

 is obviously a very important one from a practical point of 

 view — from the point of view of finding antidotes against the 

 action of pathogenic bacteria — and it deserves greater atten- 

 tion than it has hitherto received. 



The writer has himself made some experiments with regard 

 to injecting simultaneously two species. In one series the 

 bacillus of fowl enteritis was grown in broth with the swine 

 fever bacillus ; in the other, the bacillus of swine erysipelas 

 with that of swine fever, but neither in the amount of multi- 

 plication nor in the virulence of the swine fever bacillus 

 could any change be noticed. He has, however, succeeded 

 in neutralising the fatal effect on mice of the grouse bacillus, 

 if at the same time the aerobic malignant oedema bacillus 

 {see later) be injected. 



M M 2 



