BUREAU OP ANIMAL INDUSTRY. 631 



veloped sufficiently a tube of beef -infusion jjeptone was inoculated 

 from one of tliem. In this way a liquid culture was obtained from 

 the progeny of a single germ, although the preceding cultures had 

 been found pure. 



Three days later (October 4) the following? inoculations were made: Two mice, -J^" 

 each; 1 guinea-pig, i"; 1 pigeon, J«; 2 rab'oits, i and i% respectively; and 2 pigs, 5"== 

 and 3.5". Of these animals the pigeons, the guinea-pig, and the pigs remained 

 well. One of the mice escaped several days after inoculation; the other remained 

 apparently well until Octolfer 18, two weeks after inoculation, when it was found 

 dead. This long i)eriod of incubation and sudden death were characteristic of hog- 

 choli.'ra. An examination confirmed the nature of the disease. The spleen was 

 enormously enlarged with a mottled grayish and bright-red surface. The liver 

 very large, dark red, and dotted with minute whitish points of coagulation necrosis, 

 found so uniformily in inoculated mice last year. Both liver and spleen contained 

 the oval bacterium in large numbers. The lungs were deeply congested. 



Both rabbits succumbed on the seventh day, about eight hours apart. The lesions 

 were also the same as those observed heretofore. In No. 1, at the place of inocula- 

 tion, there was a small area about i inch in diameter over which the fascia covering 

 the muscles was infiltrated and thickened. There was no peritonitis, but the fat 

 about the kidneys contained patches of injected capillaries. The spleen was very 

 much tumefied, its dimensions being 6'^™, 1"^™, i""^. It was very soft and dark. The 

 liver was large; rather pale. On its surface were scattered whitish points and 



Eatches of coagulation necrosis, most numerous about the portal fissure. Kidneys 

 ut shghtly reddened. The lungs were deeply congested; the pleural sm-faces were 

 mottled everywhere with blood-red points and patches. The stomach was normal. 

 In the duodenum, at the pylorus, a band of hemorrhagic deposit encircled the tube. 

 For i inch farther the mucosa was covered with petechise. 



In the spleen, liver, lung, and kidney the bacteria of hog-cholera were very abun- 

 dant; in blood from the heart quite scarce. Cultures in nutrient liquids from liver 

 and blood proved pure. The movements of the bacteria were exceedingly active 

 when examined in a drop suspended from a cover-glass. The tube cultures in gela- 

 tine from the spleen and hver contauied the same bacterium. 



In the second rabbit rigor mortis was marked an hour after death. Locally a 

 thick pasty infiltration had formed in the subcutaneous connective tissi^e, surrounded 

 by injected vessels. Tlie spleen, liver, lungs, and kidneys presented precisely the 

 same lesions as were found in the first rabbit. There was a slight amount of serum 

 in peritoneal cavity, not containing bacteria, as a tube of beef infusion inoculated 

 from it remained sterile. The extravasation at pylorus was limited to a small 

 patch. There was, however, a circumscribed area on serosa of large intestine cov- 

 ered with petechias. The bacteria were abundant in spleen and Hver; absent in 

 cover-glass preparations of kidney, lung, blood, and peritoneal fluid. A liquid cult- 

 ure of blood contained the motile bacterium only. Tube cultures in gelatine inocu- 

 lated from the spleen and the liver also proved pure. 



These autopsies, the microscopic examination of the organs, and 

 more especially the invariably pure cultures from each animal, con- 

 firmed the supposition that the microbe obtained in Illinois was the 

 same as the one causing hog-cholera in the East. The fact that 

 ■ neither pigs nor pigeons nor guinea-pigs died does not in the least 

 weaken this conclusion. The experiments on preventive inoculation 

 show clearly that large doses of liquid cultures can be borne with im- 

 punity by the majority of swine when introduced beneath the skin. 

 The microbe may have been of a less Adrulent variety than the one 

 with which inoculations were made last year. On the other hand, a 

 most virulent case of hog-cholera was produced by feeding pure 

 cultures, as the follo%ving notes will show: 



A pig was kept without food for over twenty-four hours. A 2i per cent, solution of 

 sodium carbonate in meat broth was then given to it. Of this it consumed about one 

 liter, taking thus about 25 grams of the salt. It was then fed with about 50« of gela- 

 tine cultures and 100" of liquid cultures of the hog-cholera bacteriimi obtained from 

 rabbits wliich had succumbed to inoculation; one was obtained from the original 

 gelatine culture of the spleen made in Champaign County, Illinois. The animal was 

 found dead December 4, scarcely three days after feeding. Tiiis was the briefest pe- 

 riod of iUness thus far observed. The lesions were very pronounced. Pyramids of 



