640 



RErullT OF THE COMAMSSIONEIl OF AGRICULTURE. 



lire. The throe remaining animals wore apparently unatl'ected nearly 

 two months after exposure. At this time No. VJ7, which apj^eared 

 rather thin, was killed, to determine if any ulcerations were present. 

 But the mucous membrane of the intestine was entirely normal, with 

 no indications of former ulcerations. 



Autopsy notes of No. 199. — Slight extravasation in subcutaneous connective tissue. 

 Spleen somewhat enlarged, filled with blood, friable; considerable effusion in peri- 

 toneal cavity. Right lung in part hepatized; pleuritic adhesions to chest- wall; hem- 

 orrhage in and about pelvis of kidney; lymphatic glands purplish; extensive and 

 deep ulceration of the mucosa of large intestine. 



Pig 197, killed for examination, was very ansemic. There was some pale serum in 

 abdominal cavity. The kidneys and lymphatic glands showed evidence of chronic 

 inflammation. The lungs were exceedingly pale. No evidence of inflammation or 

 ulceration in any portion of the intestinal tract. 



It must he borne in mind that these animals were constantly ex- 

 posed for a period of several months to the virus of the disease, and 

 that a continual struggle between the organism and the invading 

 parasites must have been going on, which naturally would tend to 

 lower the vitality. Such severe conditions as these are probably 

 never realized among herds. 



The later history of No. 300 does not, however, bear out the first 

 supposition that complete immunity was attained. After being con- 

 tinually exposed in the infected pen from April 20 to Juno 21 it was 

 removed to a clean pen, where it continued to grow very weak. It 

 died July 12. The autopsy revealed a plastic pleurisy over the right 

 lung and a fibrinous exudate upon the epicardium. The mucosa of 

 the csecum was extensively necrosed; in the colon the ulcers were 

 isolated; the solitary follicles were very prominent, A small bit 

 from the epicardial exudate was placed beneath the skin of two mice. 

 One of them died on the eighteenth day. The spleen was greatly en- 

 larged. Numerous hog-cholera bacteria were present in this organ 

 and liver. The epicardial exudate of the pig must have contained 

 but very few, for they could not be demonstrated in cover-glass 

 preparations. The long period of time from the inoculation of the 

 mouse to its death is also evidence of a very small quantity of virus. 



No, 157, inoculated with the rest, became quite lame in the hind 

 limbs, so that it was thought best not to expose it to the disease in 

 the infected pen for the time being. It soon recovered its power of 

 locomotion, and was transferred to the infected pen May 25 and re- 

 moved therefrom June 28. In the new pen it grew rapidly weaker 

 and died Juii^ 28, On post morte^n examination the right lung was 

 found entirely hoDatized and adherent to the chest-wall. The mucosa 

 of ca3cum and colon was studded with large and deep ulcers; that oi' 

 the fundus of stomach was deeplj'' congested. 



It became desirable to determine whether repeated subcutaneo;;s 



