290 MICROBIOLOGY 



but retains the coloring matter very feebly, or not at all, when 

 treated after the Gram method. 



Cultivation. This organism is readily cultivated on the 

 ordinary media. It is obtained in pure cultures from the 

 heart blood or liver of a fowl just dead from the disease. 



Agar. On this medium, at 37 C., the growth is moder- 

 ately vigorous. It has a grayish glistening appearance. Iso- 

 lated colonies are from 1 to 2 mm. in diameter, convex, and 

 with sharply defined borders. Agar plates emit a peculiar 

 penetrating odor, which differs decidedly from the pungent 

 odor given off by Bacterium suisepticum. The growth on this 

 medium resembles very closely that of B. suipestifer. 



Gelatin. In this medium the growth is less vigorous. In 

 stick cultures it is more abundant along the line of inocula- 

 tion than on the surface. Isolated colonies are about 0.25 mm. 

 in diameter, appearing to the unaided eye as homogeneous 

 bodies, but slightly granular under low magnification. On the 

 surface of the gelatin the colonies are granular and slightly 

 spreading. They are not characterized by any distinctive 

 markings. There is no liquefaction or softening of the 

 medium. 



Potato. On the surface of potatoes a delicate grayish yel- 

 low growth appears after forty-eight hours when kept at a 

 temperature of 35 C. Frequently there is no development, 

 owing, presumably, to the acids in .the potato. 



Bouillon. In alkaline peptone bouillon at 36 C. the 

 growth imparts a uniform cloudiness to the liquid within 

 twenty- four hours. If the bouillon contains much sugar the 

 reaction becomes acid, otherwise it remains alkaline. A gray- 

 ish friable sediment forms in the bottom of the tube. After 

 several days' standing the growth settles, leaving a clear 

 supernatant fluid. In a simple peptone solution containing 

 one-half of 1 per cent sodium chloride the growth is less vigor- 

 ous than in the one containing the meat juice. In meat ex- 

 tract bouillons the growth is likewise feeble. In acid peptone 

 bouillon there is a very faint cloudiness imparted to the 

 liquid. 



