042 NON-PATHOGENIC BACILLI. 



very siowiy ; in contact with the air the colonies are white : in the absence 

 of oxygen liquefaction does not occur and the colonies have a reddish- 

 brown or red color. Upon the surface of agar, in the incubating oven, a 

 slimy, gray layer is quickly developed. L pon potato no growth occurs in 

 the presence of oxygen ; when it is excluded a reddish-brown layer is de- 

 veloped. In milk, at the end of ten days, solution of the casein commences 

 without previous coagulation. 



292. BACILLUS RUBIOUS (Eisenberg). 



Found in water. 



Morphology. Bacilli of medium size, with blunt ends, often united in 

 long filaments. 



Biological Characters. An aerobic, liquefying, motile, chromogenic. 

 bacillus. Forms a shining, brownish-red pigment. Spore formation not 

 observed. Grows very slowly in the usual culture media at the room tem- 

 perature not in the incubator at 37 C. Upon gelatin plates form spheri- 

 cal, finely granular colonies, which are of a reddish color at the centre and 

 around which the gelatin is slowly liquefied. In gelatin stick cultures 

 liquefaction occurs slowly and a brownish-red pigment is formed. Upon 

 the surface of agar a brownish-red layer is developed, which quickly ex- 

 tends over the surface. A similar development occurs iipon potato not 

 limited to line of inoculation. Blood serum is liquefied by this bacillus. 





' 



9 

 * 



FIG. 213. FIG. 214. 



FIG. 213. Bacterium terrno of Vlgnal, from a bouillon culture. X 1,300. (Vignal.) 

 FIG. 214. The same from a culture fifteen days old. X 1500. (Vignal.) 



293. BACTERIUM TERMO OF VIGNAL. 



Found in the salivary secretions of healthy persons by Vignal, and de- 

 scribed under the name of Bacterium termo, which was formerly given to 

 various motile bacilli encountered in putrefying infusions, many of which 

 have been differentiated by modern methods and are described under differ- 

 ent names. 



Morphology. Bacilli from 1.5 to 2 n long, constricted in the middle, and 

 0.5 to 0.7 /abroad; never u*nited in chains or filaments; possess terminal 

 flagella. 



Biological Characters. An aerobic, liquefying, motile, chromogenic 

 bacillus. Forms in gelatin cultures a fluorescent yellowish-gray pigment. 

 Spore formation not determined. Grows at the room temperature in the 

 usual culture media better at a higher temperature. Gelatin cultures give 

 off a putrefactive odor. Upon gelatin plates, at the end of twenty -four 

 hours, small, white colonies are seen ; at the end of forty-eight hours these 

 have a diameter of two to five millimetres; the centre of the colony is white 

 and opaque, and it is surrounded by a zone of liquefied gelatin which is. 



