140 



EEPORT OF THE BUREAU OF ANIMAL INDUSTRY. 



denum reddened. A grayish viscid exudate between the cascum and colon, on 

 liver and spleen. The exudate consists chiefly of swine plague bacteria, which are 

 also present in the spleen and blood. 



The following table gives the results of cultivation and inoculation 

 experiments : 



From the notes and the tabulated results it will be seen that the dis- 

 ease under examination is not true hog cholera. This is abundantly 

 proved by the absence of hog cholera bacilli from the spleen in all cases 

 examined. In true hog cholera these bacilli are rarely missed when 

 bits of spleen tissue are taken for culture, and in many cases a prick 

 of the platinum wire into the spleen is sufficient to produce a copious 

 growth. In the second place, inoculation of rabbits with material 

 from intestinal ulcers is also quite invariably successful in true hog 

 cholera in isolating the bacilli. Lastly, inoculations of rabbits from 

 diseased lung tissue in hog cholera are successful in most cases. We 

 have in the investigation before us therefore not the slightest evi- 

 dence that hog cholera germs were present in the diseased animals. 

 It might be objected that some of the inoculations were made so long 

 after the material had been collected that the specific germs died 

 meanwhile or were destroyed by the multiplication of putrefactive 

 organisms. But this objection may be answered by the fact that 

 hog cholera bacilli are very hardy, and could not have been destroyed 

 in the time elapsing between post mortem examination and inoculation 

 into animals, which was either seven or sixteen days, as indicated in 

 the table. During this period great care was taken to keep the ma- 

 terial in the cold and in a condition favorable to drying (sterile test 

 tubes plugged with cotton wool). Drying fails to destroy hog chol- 

 era bacilli, especially when, surrounded by or embedded in other 

 material, within one month at the shortest. When these facts are 

 taken into consideration, the disease can not be pronounced hog 

 cholera, although strikingly resembling it in most of the animals 

 examined. There is but one alternative to be considered. The germ 

 producing the disease in the intestinal tract may not be accessible by 

 the methods which were used, '/. e. , it may not be capable of infect- 

 ing rabbits and mice and destroying them. It may be limited to the 

 mucous membrane of the digestive tract so that it can not be obtained 

 in cultures, made from internal organs, such as the spleen. This 

 theory seemed at first a probable one when a few of the inoculated 

 rabbits died with what appeared to be metastatic abscesses in the 

 walls of the caecum, in one case in the heart nrnscle, although all 

 the cultures from these animals remained sterile. It seemed reason- 



