286 ORGANISMS RESEMBLING BACILLUS TYPHOSUS. 



4. Its growth in media containing sugar is accompanied 

 by the evolution of gas and a peculiar odor. 



5. Milk is coagulated within from thirty-six to forty-eight 

 hours. The color of litmus-milk is changed to red because 

 of the formation of acid. 



6. In nutrient gelatin or agar containing lactose and litmus, 

 and of a slightly alkaline reaction, the colonies of the colon 

 bacillus are red, those of the typhoid bacillus blue. 



7. When grown in solutions of peptone the colon bacillus 

 produces indol ; the typhoid does not. 



8. The colon bacillus grows luxuriantly, whereas the typhoid 

 bacillus does not grow at all, in asparagus solutions. 



9. The colon bacillus gives the agglutination reaction with 

 the blood of animals inoculated with this bacillus, but not 

 with typhoid blood. Bacillus typhosus agglutinates only with 

 typhoid blood. 



Bacillus Enteritidis. 



This organism was cultivated by Gaertner from the tissues 

 of a cow suffering from an intestinal disease ; and from the 

 spleen of a man who was poisoned by eating some of the flesh 

 of the cow. 



The morphology of bacillus enteritidis is almost identical 

 with that of the colon bacillus. 



It also resembles it in culture, except that the growth on 

 potato is white or yellowish-white. It does not produce indol. 



It is differentiated from the colon bacillus by its ability to 

 cause infection when swallowed and the absence of the indol 

 reaction. It differs from the typhoid bacillus in that it coagu- 

 lates milk, produces acids and gases, and does not agglutinate 

 with typhoid blood. 



Bacillus Dysenteriae (Shiga's Bacillus). 



During a recent epidemic of dysentery in Japan, Shiga 

 succeeded in isolating a characteristic organism from the intes- 

 tinal discharges of dysentery patients. 



Morphology and biology : The organism belongs to the colon 

 group. It is a short, thick rod, with rounded ends, has no 



