CHAPTER VI 



BACTERIA AS MAN'S INVISIBLE FOES 



WE have seen that the bacteria in general 

 are not only curious and interesting 

 as objects of study, but in the work which they 

 are ceaselessly and silently doing they are 

 absolutely indispensable to the continuance 

 of the higher forms of life upon the earth. 

 But unfortunately there is another darker 

 side to the picture. Among the myriads 

 of useful as well as harmless bacteria, we have 

 lately learned that there are a few forms which 

 find the most favorable conditions for their 

 life and growth in the bodies of men and some 

 of the higher animals. 



Most of these do not grow well in nature 

 as other bacteria do, nor do they thrive on 

 ordinary decomposing organic matter. They 



look very much like the more common 



60 



