224 MANUAL OF BACTERIOLOGY. 



ture in decomposing vegetable material and in the stomachs 

 of ruminant animals; a large, thick rod with round ends, 

 often arranged in chains; actively motile; anaerobic; forms 

 spores, which are located in the center of the bacillus and 

 give it a spindle-shaped form, or at one end when it has the 

 outline of a tadpole; has not been cultivated satisfactorily 

 on ordinary media; grows best at 35 to 40 C. ; decom- 

 poses carbohydrates with the formation of butyric acid ; 

 decomposes cellulose. Organisms of similar form have 

 been found as fossils belonging to the carboniferous period. 



Bacillus butyricus (Hueppe). Found in milk; appears 

 as a small, irregular rod, also forming threads; very actively 

 motile ; aerobic ; rapidly liquefies gelatin ; forms centrally 

 located spores; grows best at 35 to 40 C. ; grows rapidly 

 on ordinary media; coagulates milk, redissolving the coag- 

 ulum, producing also butyric acid. A large number of 

 bacteria, both aerobic and anaerobic, produce butyric acid 

 fermentation. 



Bacillus megatherium. Obtained by DeBary from 

 cooked cabbage-leaves ; common on plants and earth ; a large 

 bacillus with rounded ends, often forming chains; motile; 

 slowly liquefies gelatin ; aerobic ; forms spores, especially in 

 potato cultures; grows rapidly at room temperature on the 

 ordinary media. 



Bacillus mesentericus vulgatus (Potato bacillus). 

 Found on potatoes; common in earth; a large, long rod 

 with rounded ends, often forming long chains ; motile ; it 

 is stained by Gram's method ; liquefies gelatin ; aerobic ; 

 forms spores; grows rapidly, best at about 20 C. ; grows 

 on ordinary media, forming on potato a thin, wrinkled 

 membrane which spreads rapidly over the surface. It 

 coagulates milk, redissolving the coagulmn. It possesses 

 numerous flagella. The spores are extremely resistant to 

 heat. 



