BUREAU OP ANIMAL INDUSTRY. 613 



only eight days after infection. Tlie skin on abdomen was reddened in patches; 

 tlie subcutaneous tissue diffusely. The superficial inguinals, as well as the glands 

 in the abdomen, were deeply congested, the cortex more especially. Those of the 

 thorax wore nearly pa,le. The spleen was dotted with a few punctlform elevations. 

 Beneath the epicardium and endocardium of both auricles and the endocardium of 

 the left ventricle were extensive patches of extravasated blood. Kidneys enlarged 

 and congested throughout. The lesions of the ileum, caecum, and colon in this ani- 

 mal were quite as extensive as those of the case just described; there were noiilcers 

 in the rectum, however. Those of the colon had black centers, pointing to a recent 

 origin from blood extravasations on the surface of the mucous membrane. 



In the spleen of this case the characteristic bacteria of hog-cholera were exceed- 

 ingly numerous, as determined by cover-glass preparations. Two hquid cultures 

 proved pure when tested on gelatine plates. In the needle tracks of a tube culture 

 in gelatine innumerable colonies appeared in a few days. Inoculations from sub- 

 sequent cultures proved equally positive. 



Pig No. 156 was fed with the viscera of No. 159 February 18, and, after manifest- 

 ing the usual symptoms of hog-cholera, died February 25, seven days after feed- 

 ing. Among the marked lesions produced by the disease was a complete necrosis 

 of the upper two-thirds of the colon, with scattered ulcers along the lower third. 

 About an eighth of a foot of the lower portion of the small intestine, beginning at 

 the valve, was necrosed, without manifesting distinct ulceration, for which the pe- 

 riod of disease was evidently too brief. In the spleen there were numeroua small 

 grayish spots, probably centers of necrosis, as they showed no longer cell structure 

 when crushed on a shde and stained. The fundus of the stomach was also deeply 

 congested. 



The spleen, to which organ the microscopic examination was limited, contained 

 the characteristic oval bacteria, as shown by cover-glass preparations. Three liquid 

 cultures made from the same organ were found to be pure cultures of the same 

 microbe when tested by line cultures, A tube culture in gelatine developed in each 

 needle track numerous non-hquef ying colonies. 



In these animals the mode of introduction of the virus determined 

 the seat of the severest lesions. It is prohable that the food passes 

 quite rapidly through the small intestine; that in the stomach the 

 action of the bacteria is more or less limited, because they have not 

 suflficient time to multiply, and probably becaus'e hindered by the 

 acid condition of the organ, though they will multiply with consid- 

 erable vigor in slightly acid solutions. The prolonged stay of the food 

 in the large intestine permits multiplication, and thereby causes the 

 first and severest lesions to appear here. When these have become 

 very extensive, so as to paralyze the action of the large intestine, the 

 ileum becomes involved in a similar manner, possibly by a partial 

 stoppage of the infectious matter in this portion of the intestine. 

 This view is supported by the evidence of the above and otheTvost 

 mortem examinations in which the disease was produced by feeding. 



This mode of infection by feeding viscera w.as used to keep up the 

 disease at the experimental station, as simple infection in pens could 

 not always be relied upon in furnishing cases for investigation. 

 These few cases might therefore be supplemented by many others to 

 show the ease with which infection may take place in this way. 

 ^ In general two types of disease appear. In one the lesions are 

 limited quite exclusively to the alimentary tract, involving the 

 stomach, the large intestine, and often the ileum, less frequently the 

 jejunum. There may be complete necrosis of the mucosa in the colon 

 and ileum, with intense reddening of the fundus of the stomach. 

 The internal organs are but slightly affected. There are few or no 

 hemorrhages, and the bacterium is very scarce in the spleen and 

 other organs, so that its presence is only determinable by culture. 



In the other type the extensive local lesions are replaced by hem- 

 orrhagiclesions of the internal organs, involving the spleen, kidneys, 

 lymphatic glands, lungs, and serous membranes generally. Besides 

 these, the mucous membrane of the stomach and intestines may be 



