PATHOGENIC BACTERIA 147 



The microscopic appearances in no way resemble the cholera 

 colony. 



Stab-cultures. The gelatin is liquefied from above down- 

 ward, like a stocking in appearance, and in three days is 

 completely liquid. 



Potato. At ordinary temperature a thick gray layer cover- 

 ing the whole surface. 



Water. It soon perishes in water. 



Staining. Ordinary anilin dyes. 



Pathogenesis. For man it has no specific action. If it is 

 injected into guinea-pigs, prepared as described under the 

 cholera bacillus, they die, the intestines having a foul odor, 

 and the bacilli then found in great numbers. 



Spirillum Tyrogenum (Deneke). Origin. In 1885 Den- 

 eke found in old cheese a spirillum very similar in appearance 

 to the cholera spirillum. 



Form. The same as the cholera vibrio. 



Properties. Very motile, liquefy gelatin. 



Growth. They grow quicker than the cholera, and slower 

 than the Finkler; they are also facultative aerobic. 



Colonies. At first resemble cholera colonies; have, however, 

 a yellow-green iridescence and are more irregular; also grow 

 more rapidly. 



Stab-cultures. A thick line along the needle-track and yellow 

 colonies forming at the bottom; on the surface a bubble of air 

 similar to the cholera. The gelatin is liquid in two weeks; on 

 agar, rapid slimy yellowish growth. 



Potato. At brood-heat a thin yellow membrane, but not 

 always constant. Staining, as cholera bacillus. 



Pathogenesis. When injected into animals prepared as for 

 the cholera bacillus, a certain number die. 



Vibrio Metchnikovi (Gamaleia). Origin. In the intes- 

 tines of fowls suffering from a gastro-enteritis, common in 

 Russia. Gamaleia found a spirillum which bears so close a 

 resemblance to the cholera bacillus, both in form and growth, 

 that it cannot be distinguished by these characteristics alone. 



Form. As cholera bacillus. 



