268 BACTERIA IN INFECTIOUS DISEASES. 



tity of the culture-fluid, we soon exclude all non- 

 living particles, and soluble substances as well, 

 contained in the material introduced as seed into 

 culture No. 1 (see remarks on p. 238). 



In such a series, which has been carried as far 

 as the one-hundredth successive culture (Pasteur), 

 the virulence of the last culture-fluid is as great as 

 that of the first ; and, as the culture-fluid itself is 

 innocuous, this virulence can be ascribed only to 

 the living bacilli contained in it, which are the 

 direct descendants of those present in the minute 

 drop of anthrax blood used to inoculate culture 

 No. 1. 



Experiments of this kind are conclusive as to 

 the essential etiological role of the anthrax bacil- 

 lus, but they do not, of course, explain its modus 

 operandi. Pasteur has shown that the bacillus is 

 aerobic, i.e., that its development depends upon 

 the presence of oxygen, and there can be no 

 doubt that, during its rapid multiplication in the 

 blood of a living animal, it deprives this fluid of 

 its oxygen, and also of other constituents required 

 for its own nutrition. The deprivation of oxygen 

 is shown by the symptoms, dyspnoea, cyanosis, 

 depressed temperature, and finally death, with all 

 the symptoms of asphyxia. It also acts mechan- 

 ically, by blocking up the capillaries, and pro- 

 ducing emboli and hemorrhagic extravasation in 

 various parts of the body. In addition to this, we 

 have evidence that, as in other forms of septicae- 

 mia, a potent chemical poison is produced as a re- 



