SWINE FEVER. 353 



administered with milk to two pigs. Five days afterwards one pig 

 died ; and the mesenteric glands were congested, and the mucous 

 membrane showed spots of necrosis. The other pig was killed, and 

 there were ulcers in the colon. In a third experiment, eight pigs 

 were fed with milk and broth cultures. These pigs were all killed 

 at different dates, and most of them had ulceration of the colon ; 

 in control experiments the intestine was normal. 



M'Fadyean compared his bacillus with a culture of the hog- 

 cholera bacillus, and found that the American organism grows at a 

 lower temperature in gelatine, and colonies appear in plates much 

 earlier. They produce a less transparent and thicker growth, and 

 much greater turbidity in broth and a more abundant sediment. 

 On potato they form an abundant growth at 37 C., at first 

 yellow, later brown, with considerable resemblance to a glanders 

 culture. 



Colonies upon gelatine-agar are distinguished by their opacity 

 and sharp outline. Agar, potato, and broth cultures of the American 

 organism consist of short ovoid forms like the bacilli of fowl cholera, 

 while the bacillus isolated by M'Fadyean has a closer resemblance 

 to the bacillus of glanders. M'Fadyean asserts that the American 

 organism is not pathogenic to the pig. Pigs after feeding on broth 

 cultures remained healthy, and showed no trace of swine fever when 

 killed from one to three weeks afterwards. On the other hand, 

 broth cultures of his bacillus produced the characteristic ulceration 

 of the bowel. M'Fadyean claims, therefore, to have discovered the 

 true pathogenic organism of swine fever. He does not appear to 

 have compared this bacillus with that obtained from the epidemic 

 of swine fever at Marseilles. From the description of the mor- 

 phological and other details there seems to be a close resemblance 

 between the two. 



Not less than three and possibly four species of bacilli have been 

 cultivated from swine fever, two at different times by Klein, one 

 by Reitsch Jobert and Martinaud, and one by M'Fadyean ; and 

 cultures of all these bacilli have been credited with producing swine 

 fever in experimental animals, and each one has been pronounced 

 to be the contagium of the disease. We must conclude either that 

 contaminated cultures were inoculated in some cases, or, what is 

 far more probable, the swine fever which resulted in experimental 

 animals was due to accidental infection ; and until a bacillus has 

 been cultivated from swine fever from which another investigator 

 can prepare sub-cultures, and with those sub-cultures produce the 

 typical u Iterations of swine fever in pigs on a farm, or on premises 



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