NON-PATHOGENIC BACTERIA 



93 



thrust for a short distance. Agar, a very beautiful yellow, 

 along the stroked surface. 



Sar cilia Aurantica. Flava, rosea, and alba are some of the 

 other varieties. Many are obtained from beer, 



Sarcina Ventriculi. (Goodsir.) (Fig. 47.) 



Origin. Stomach of man and animals. 



Form, Colorless, oval cocci, in groups of eight and packets 

 of eight. 



FIG. 47. 



Sarcina ventriculi from stomach-contents ; X 530. (Van Valzah and Nisbet.) 



Properties. Does not liquefy gelatine ; shows the reaction of 

 cellulose to iodine. 



Growth. Rapid. At end of thirty-six hours, round, yellow 

 colonies, from which colorless cocci and cubes are obtained. 



Habitat. They are found in many diseases of the stomach, 

 especially when dilatation exists. Also normally; increased 

 when fermentation occurs. 



Boas-Oppler Bacillus, also known as the Bacillus geniculatus. 

 Owing to the faculty possessed by this organism of growing in 

 the presence of amounts of lactic acid sufficient to check the 

 development of all other lactic-acid formers, it usually pre- 

 dominates in stomach-contents containing large amounts of 

 this substance. The parent type is composed of short rods, 

 but in the presence of considerable amounts of lactic acid these 



