ARTIFICIAL PRODUCTION OF TUBERCLE. 1$ 



substance of the patches. Ulceration also occurs in specks in them, but it 

 seldom affects the whole patch. 



In the cEecum, the patches are also much enlarged ; but the single follicles 

 are less distinct than in the small intestine. Ulceration of the whole or of 

 portions of the patch are not uncommon ; and, when present, they have often 

 a cheesy floor, in which are numerous small granulations, like those seen in the 

 floor of a tuberculous intestinal ulcer in man. Thickening of the margin is 

 less marked; but in explanation of this, it may be stated that the mucous 

 membrane of this portion of the intestine is much thinner in the guinea-pig 

 than in man. With this exception, they present all the characters of the 

 tuberculous as contrasted with the typhoid ulcer of the intestine. The soHtary 

 glands of the small intestine are occasionally enlarged ; sometimes also they 

 are cheesy. 



Microscopic examination of Peyer's patches in the stage of enlargement 

 shows cells crowded in the follicles in a manner similar to that observed in the 

 lymphatic glands and in the spleen, and in many parts undergoing fatty dege- 

 neration. Once I have seen a bloody slough adhering to the ulcerated surface, 

 and once punctiform extravasations in other parts of the mucous membrane 

 of the intestines. With the last exception, I have seen no other signs of 

 haemorrhage. The ulcers always spring from Peyer's patches or from tlie 

 solitary glands, and not from other parts of the intestine. The stomach has 

 always been unaffected. 



The mesenteric glands are almost invariably affected, even when distinct 

 changes are not discoverable in the intestine itself. One gland shows this 

 most prominently ; viz., the large one situated in the part of the mesentery 

 attached to the ileo-csecal valve. The large glands in the hilus of the liver and 

 the gastro-hepatic omentum are also very commonly affected. Their changes 

 are similar to those of the axillary glands. 



In the peritoneal cavity, dropsy is very common. Lebert attributes it to 

 the obstruction of the circulation through the liver, and I think with reason. 

 I have once seen hsemorrhage into the cavity. I could not discover its source, 

 but all the branches of the portal vera were loaded with blood. The chief 

 change, however, to which I wish to direct your attention in this part occurs 

 in the omentum. Here, scattered thickly through the tissue, are found 

 granules varying in size from a pin's point to a poppy-seed, seldom much 

 larger. They precisely resemble the grey granulations found in tuberculous 

 peritonitis in man, except that I have only once found any sign of inflam- 

 matory action attending the process. This was in a case of general tuber- 

 culous peritonitis following abortion. 



