SWINE PLAGUE. 



517 



aspects. The following forms may be seen — very minute, well 

 defined, prominent yellowish-whitish specks of the size of a 

 millet or hemp seed; then somewhat larger, more flattened, 

 prominent, circular or oval, yellowish patches (with which in 

 one case the whole mcuous membrane of the caecum seemed 

 quite covered) of the size of a hemp seed, up to abont one- 

 eighth of an inch in diameter ; next, flat, circular, or slightly 

 oblong patches, situated on the crust of a fold of the mucous 

 membrane, in size from one -eighth to one inch in diameter, 

 generally black or grey (from bile pigment), except a very con- 

 spicuous, and, I may almost say, characteristic prominent rim, 

 which is yellow. The ulcer generally shows a pale central or 

 eccentric disc, around which the rest of the ulcer is arranged as 

 concentric rings. Between these flat ulcers with concentric 

 layers, and those uniform, yellowish-white, prominent patches 

 and nodules, there are all interme- 

 diary forms. This is easily under- 

 stood, if it is borne in mind that as 

 the latter increase in size, the central 

 part is transformed into that black 

 or greyish mass. Besides these, there 

 are very often formed on the surface 

 of the mucosa minute whitish specks, 

 just perceptible by the unaided eye. 

 In one single instance have I seen 

 ulcerations of the lower part of ileum. 

 This case had exceedingly numerous 

 ulcerations of the large intestines. 

 The two ulcers of the ileum were 

 quite different from the ulcers gene- 

 rally found in the large intestine, for 

 they were oblong, deep pits, sur- 

 rounded by a thick, prominent wall 

 of swollen mucous membrane, very 

 much the same as ulcers of human 



typhoid. But under any circum- American pig slaughtered at Liver- 

 ]_ ,r ■ 1 pool, May 1879. 



stances tiie microscope reveals a «, iiio-cfecal opening, 

 marvellous difl'erence between the ^' ^' ^- Ulcers in various stages. 

 two diseases ; for in the pig these patches, whether nodules or 

 ulcers, have absolutely nothing whatever to do with lymphatic 



O'-T 



Fig. 14b. — Portion of caecum of 



