PATHOLOGICAL CHANGES. 311 



extensive leucocytic emigration, and sometimes small 

 haemorrhages may be observed. It is at this period that 

 the typhoid bacilli are most numerous in the patches, 

 groups, occurring between the cells, being easily found. 

 There now takes place a necrosis of the cells which may 

 involve the whole tissue of the patch, and a slough forms 

 which, being cast off, leaves an ulcer. This necrosis is 

 evidently in chief part the result of the action of the toxic 

 products of the bacilli, which now gradually disappear 

 from their former positions, though they may still be 

 found invading the deeper tissues and at the spreading 

 margin of the necrosed area. They are also described as 

 occurring in the lymphatic spaces of the muscular coat. 

 It is important to note that the ulcers in a fatal case of 

 typhoid may vary much in numbers. The whole lower 

 third of the small intestine may be ulcerated, or only two 

 or three ulcers may be present even in a case where death 

 has occurred by exhaustion. Further, small ulcers may 

 also occur in the lymphoid follicles of the large intestine. 



The condition of the mesenteric glands in typhoid is 

 important. Those corresponding to the affected part of 

 the intestine are usually enlarged, sometimes to a very 

 great extent, the whole mesentery being filled with glandular 

 masses. In sucli glands there may be acute inflammation 

 attended with haemorrhages, and even necrosis in patches 

 may occur, but this is never the outstanding feature as in 

 the case of the Peyer's patches. Sometimes on section 

 the glands are of a pale-yellowish colour, the contents 

 being diffluent and consisting largely of leucocytes. Typhoid 

 bacilli may be isolated both from the glands and the 

 lymphatics connected with them, but here the B. coli is in 

 addition often present. 



The spleen is enlarged, on section usually of a fairly 

 firm consistence, of a reddish-pink colour, and in a state of 

 acute congestion. Of all the solid organs it usually con- 

 tains the bacilli in greatest numbers. They can be seen in 

 sections, occurring in clumps between the cells. There is 

 no evidence of local reaction round these clumps. Similar 





