BUREAU OF ANIMAL INDUSTRY. 



651 



The extensive necrosis of tlie mucous membrane of the csecum and 

 upper portion of colon, witli the absence of any acute inflammation 

 elsewiicre, gave evidence of a chronic case of hog-cholera. No. 20G, 

 though still alive, is emaciated. 



The two remaining check pigs, which were exposed with the pre- 

 ceding animals in the same infected pen, both died of hog-cholera. 

 No. 211 found dead June 21. The most marked changes were a small 

 number of ulcers on a pale mucous membrane scattered over the caecum 

 and colon. No. 210 lived a month longer than its mate. The exist- 

 ence of hog-cholera was demonstrated by a general necrosis of the 

 mucous membrane of the ceecum and an extensive pigmentation in 

 the remainder of the large intestine. The lungs were adherent in 

 places and much congested. 



When we gather together the facts presented by this experiment 

 we shall find a certain number of interesting deductions springing 

 therefrom. In the first place we note the peculiarity of the intes- 

 tinal lesions of the two animals which died from some unknown cause, 

 presumably not hog-cholera. We next jjoint to an additional dem- 

 onstration of the specific nature of the bacterium of hog-cholera, 

 for out of eight inoculated four died, and the age of the lesions cor- 

 responded well with the length of time elapsing between inoculation 

 and death. 



Those animals which resisted the inoculation were in part protected, 

 as two among four were still alive on August 17, and the remaining 

 two died, probably from effects of the ulceration, months after ex- 

 posure. 



♦These animals were one and a half months old at date of inoculation. 



t Checks. 



Having determined that even large doses of liquid cultures of the 

 bacterium of hog-cholera can be borne without producing the dis- 

 ease in most cases, it was thought advisable to make two inocula- 

 tions of strong virus, a first one with a small quantity and a second 

 with a large quantity. 



First inoculation, April 21: Nos. 214, 227, 223, and 222 received i<=<' 

 of a tliird culture in beef infusion containing 1 per cent, each of pep- 

 tone and glucose. The liquid was diluted with sterile salt solution 

 so as to make ■^'"'. It was injected one-half beneath the skin of each 

 thigh. 



Second inoculation: After waiting two weeks in order to determine 

 whether the inoculation had not produced the disease, a second in- 

 jection was practiced May G, the thirteenth and fourteenth culture 

 of the same series being used for this purpose. The animals received 



