90 ESSENTIALS OF BACTERIOLOGY. 



Protective Vaccination. Animals have been rendered immune 

 by various ways by inoculation of successive attenuated cul- 

 tures ; also with sterilized cultures that is, cultures containing 

 no bacilli, and with cultures of other bacteria. 



Habitat. The anthrax disease seems confined to certain dis- 

 tricts in Siberia, Bavaria, and Anivergne, and mainly during the 

 summer months. 



The bacillus has never been found free in nature. 



Bacillus Tuberculosis. (Koch.) 



This very important bacillus was first described, demonstrated, 

 and cultivated by Koch, who made his investigations public on 



FIG. 50. 





' "X 



^ * 



Tubercle bacilli in sputum, carbol-fuchsin, and methylin blue. Zeiss 1:12 oil 

 immersion. 



the 24th of March, before the Physiological Society of Berlin, 

 in the year 1882. 



Origin. In various tubercular products of man and other 

 animals. 



