26 HOG C^EOLEKA 



cholera. In later years Uhlenhuth and his co- 

 workers reported finding it in the intestinal tracts 

 of many healthy swine. Jordon, in this country, 

 was unable to identify it in any normal hogs which 

 he examined, and neither was Tenbroeck. Both 

 of these investigators regard Uhlenhuth 's work as 

 inconclusive owing to the fact that he did not 

 differentiate correctly between B. suipestifer and 

 B. paratyphoid B. Smith states that the only dis- 

 tinction that can be made between the two is that 

 the former is pathogenic for rabbits, while the 

 latter is not. 



Eabbits and guinea-pigs succumb to small sub- 

 cutaneous injections of cultures of B. suipestifer, 

 rabbits being somewhat more susceptible. Swine 

 are not easily infected with subcutaneous injec- 

 tions, but large intravenous doses prove fatal. 

 According to Welch, small doses may lead to for- 

 mation of the "button ulcers" observed in chronic 

 hog cholera, and Smith secured like results by 

 feeding pigs bouillon cultures. 



The part played by this organism in producing 

 swine disease in the field is not well defined, as 

 most work with it ceased as soon as the filterable 

 virus was accepted as the cause of epizootic hog 

 cholera. There is good evidence that it is one 

 cause of the "button ulcers " just mentioned, and 

 it is likewise probable that, acting in the role of 

 secondary invader, it is responsible for the en- 



