594 BACTERIOLOGY. 



Stains with the usual aniline colors, but not by 

 Gram's method. 



Biological Characters. An aerobic, liquefying, motile 

 spirillum. Upon gelatin plates the vibrio Metschnikovi 

 grows considerably faster than the cholera vibrio; small, 

 white punctiform colonies are developed at the end of 

 twelve hours; these rapidly increase in size and cause 

 liquefaction of the gelatin within twenty-four to thirty 

 hours. At the end of three days large, saucer-like 

 areas of liquefaction may be seen, the contents of which 

 are turbid, as a rule. Under the microscope the 

 colonies appear as yellowish-brown granular masses, 

 which are in active movement, and the margins are 

 surrounded by a border of radiating filaments. In 

 gelatin stick cultures the growth is almost twice as rapid 

 as the cholera bacillus. In bouillon at 37 C. devel- 

 opment is very rapid, and the liquid becomes clouded 

 and opaque, and a thin, wrinkled film forms upon the 

 surface. On the addition of pure sulphuric acid to 

 twenty-four-hour peptone cultures a distinct nitroso- 

 indol reaction is produced. Milk is coagulated and 

 acquires a strongly acid reaction. The spirillum does 

 not clump and lose its motility with the diluted serum 

 from an animal immunized to cholera. 



Pathogenesis. The vibrio Metschnikovi is pathogenic 

 for fowls, pigeons, and guiaea-pigs. A small quantity 

 of a culture injected into the breast muscles of chickens 

 and pigeons causes their death with the local and gen- 

 eral symptoms of fowl cholera. At the autopsy the 

 most constant appearance is hypersemia of the entire 

 alimentary canal. A grayish-yellow liquid, more or 

 less mixed with blood, is found in considerable quan 

 tity in the small intestine; the spleen is not enlarged, 



