HEMORRHAGIC SEPTICEMIA GROUP 303 



by agglutination may be practicable, but further work is needed 

 before its usefulness can be ascertained. 



Transmission. The means by which the organism spreads 

 from one animal to another, and by which it gains entrance to the 

 body, is not well understood. 



Other Hemorrhagic Septicemias of Animals 



Organisms belonging to this group have been isolated from a 

 considerable number of other animal diseases in addition to the 

 ones which have already been described. Rabbit septicemia or 

 rabbit plague (Bacillus cuniculicida) , pneumoenteritis, or hemor- 

 rhagic septicemia of sheep and of the horse, infectious pneumonia 

 of goats, Biiffelseuche or pasteurellosis of the buffalo, dog typhoid 

 or dog pasteurellosis, hemorrhagic septicemia of elephants, of 

 geese, wild birds, and many other animals have been ascribed to 

 Bacillus septicemice hcemorrhagicce. As has been before stated, the 

 evidence in some of these cases seems to be inconclusive. 



Bacillus pestis 



Synonyms. Bacterium pestis; B. pestis bubonicce. 



Disease Produced. Bubonic plague in man and rodents. 



Yersin and Kitasato, in 1894, independently described the or- 

 ganism which causes bubonic plague. Since that time it has been 

 isolated and described by many observers in numerous outbreaks. 



Distribution. The disease is endemic in parts of China and 

 India. At various times it has spread as an epidemic over the 

 entire civilized world. Cases have been reported within recent 

 years in most of the civilized countries, but it has not gained a 

 foothold and spread in any countries except those of southern 

 Asia and China. 



Morphology and Staining. The Bacillus pestis morphologi- 

 cally resembles the other members of this group. It is small 

 usually about 0.5 to 0.75 by 1.5 to 2 it. It sometimes occurs in 

 short chains, but is usually single. Involution forms are produced 

 so readily upon appropriate culture-media, such as partially 

 desiccated agar and salt agar, that their development has been 

 regarded as diagnostic. Capsules may sometimes be demonstrated 

 on culture-media, but not in tissues. The bipolar staining of 



