THE VITAL PHENOMENA OF BACTERIA. 141 



R. Koch. According to the conception ad- 

 vanced by the latter it is the bacillus, always 

 constant, that is the " cause " of the typical or 

 specific fermentation or disease : it alone pro- 

 duces the uniformity of effect. In reality 

 the bacillus adapts itself to its surroundings 

 and remains the same so long as they remain 

 the same, but changes if they vary. The con- 

 stancy of those external conditions to which bac- 

 teria must adjust themselves alone determines 

 the uniformity of the effects produced. 



The full significance of the foregoing facts 

 may perhaps be gathered from the following 

 considerations. If a person contracts a bacterial 

 disease, tuberculosis for example, then, accord- 

 ing to Koch, only the tubercle bacillus can be 

 held responsible. It is just this belief that 

 has made the science of bacteriology so popu- 

 lar in the eyes of the unreflecting multitude 

 and of many easy-going physicians. We 

 need no longer, it is supposed, be solicitous 

 about our own mistakes and peccadilloes. 

 Come what may, we are morally protected, 

 and, secure in the consciousness of our in- 

 dividual merit, we now lay all responsibility 

 upon " the bacteria " as formerly upon " catch- 

 ing cold." A fatal blow is dealt to these self- 

 deceptions and illusions by simply pointing to 

 the fact that bacteria provoke fermentation 



