EELATION OF PATHOGENIC TO SEPTIC BACTERIA. 57 



broth, in which the bacillus mass remains quiet at the bottom of 

 the vessel, no spores are formed, and it is such a cultivation 

 which proves inactive on mice only. In Pasteur's case the sheep 

 inoculated with such bacilli (prevented from forming spores) are 

 not killed by anthrax, but " vaccinated," and protected against 

 the most virulent anthrax material. I have not yet succeeded 

 in discovering the method employed by M. Pasteur (and the 

 details of which he has not published) for the production of 

 " vaccine" protective against anthrax; and I can only say that 

 in the case of mice there is no such diminution of virulence as 

 Pasteur has obtained in the cultivation with which he inocu- 

 lates his sheep. The mice not killed or even injured by the 

 pure bacillus threads of our cultivations succumb without fail 

 to an inoculation with spores or blood bacillus, or to an inocu- 

 lation with the early stage of a new cultivation of bacillus de- 

 rived from the former cultivation. This inefficacy of the bacillus 

 of the cultivation on the mice, after several days' cultivation, 

 must be borne in mind when judging of Buchner's results 

 above quoted. Buchner (I.e., p. 384) finds the greatest irre- 

 gularity in respect of the supposed deterioration in virulence 

 of the cultivations, for while in one series, the third and fourth 

 cultivation is inactive ; the fifth active if used in large quan- 

 tity; in other series other results are observed. Granted that 

 Buchner had pure cultivations, of which, however, there is no 

 sufficient evidence — ^see Koch (I.e., p. 25) — these irregular 

 results, I think, might be explained by the assumption that 

 the active cultivations were fresh or contained spores, the 

 inactive ones were of some age and had no spores, Buchner's 

 cultivations being carried on in a fluid medium, and being 

 used solely on white mice. More difficult is it to explain 

 Greenfield's statements. He speaks of mice, guinea-pigs, 

 and rabbits as all giving identical results under all circum- 

 stances, and this as if the identity of result were matter of 

 course and of necessity. I do not propose to comment on his 

 statements. 



As has been already indicated, a given cultivation of Ba- 

 cillus anthracis, although speedily becoming inactive on 



