CHAPTER XVIII 

 BACILLACE^: THE SPOROGENIC ANAEROBES 



The bacteria of this group are hindered in their development 

 by the presence of free oxygen and their artificial culture is ordi- 

 narily successful only when they are protected from oxygen, at 

 least in the early stages of development. Like the sporogenic 

 aerobes, they live in the soil, but they are associated here more 

 especially with decomposing materials of animal origin, and are 

 less frequently found in soils which have not received fertihzers 

 from animal sources. There is good reason to believe that their 

 essential habitat is the intestinal canal of animals, especially the 

 mammals, and that their life in the soil does not represent the 

 most active stage of their existence, but that they reach the soil 

 with animal excreta and the bodies of dead animals and continue 

 to live in the soil for a considerable period. For this group of 

 bacteria the Committee of the Society of American Bacteriologists 

 has suggested the generic nam.e, Clostridium Prazmowski 1880. 



Clostriditim Edematis (Vibrion septique). — Pasteur in 1877 

 injected infusions of putrid flesh into laboratory animals and 

 produced a fatal subcutaneous edema with penetration of the 

 bacteria into the blood in some instances. The organism which he 

 called "Vibrion septique" was found to be an obligate anaerobe, 

 the first anaerobic organism ever recognized. Koch (1881) 

 studied the organism in pure culture on soHd media and named 

 it Bacillus edematis maligni. 



The bacillus is very widely distributed in soil and dust, and 

 is very common in the feces of herbivorous animals. It is es- 

 pecially abundant in putrefying animal matter. The cell is about 

 ifi thick by 3 in length, although considerable variation in size 

 and shape occurs. It is usually slightly motile and possesses 



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