PATHOLOGICAL CHANGES. 333 



extent, the whole mesentery being filled with glandular masses. 

 In such glands there may be. acute inflammation, and occasion- 

 ally necrosis in patches occurs. 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 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 congestion. 

 Of all the solid organs it usually contains the bacilli in greatest 

 numbers. They can be seen in sections, occurring in clumps 

 between the cells, there being no evidence of local reaction round 

 them (Fig. 113). Similar clumps may occur in the liver in any 

 situation, and without any local reaction. In this organ, how- 

 ever, there are often small foci of leucocytic infiltration, in 

 which, so far as our experience goes, bacilli cannot be demon- 

 strated. Clumps of bacilli may also occur in the kidney. 



In addition to these local changes in the solid organs there are also wide- 

 spread cellular degenerations in the solid organs which suggest the circulation 

 of soluble poisons in the blood. 



In the lungs there may be bronchitis, patches of congestion and of acute 

 broncho-pneumonia. In these, typhoid bacilli may sometimes be observed, 

 but evidence of a toxic action depressing the powers of resistance of the lung 

 tissue is found in the fact that the pneumococcus is frequently found in such 

 complications of typhoid fever. 



The studies of Voinot and of Nichols show that the nervous system is often 

 seriously affected by marked alterations in the motor nerve cells of the ventral 

 horns of the spinal cord and in the cells of the posterior root ganglia, with 

 extensive degeneration of the peripheral nerves as well. Meningitis and 

 brain abscess have been reported by McDaniel and McClintock. 



The blood in typhoid fever in probably 80 per cent of all cases contains 

 the specific bacillus, as shown by the researches of Schottmliller, Auerbach 

 and Unger, and Cole; at times the bacilli precede the appearance of the 

 agglutination phenomenon. Judging from the results obtained by Karlinski, 

 Richardson, Gwyn, and others B. typhosus can be isolated from the urine in 25 

 per cent of all cases of the disease. That the rose-spots contain the bacilli 

 seems undoubtedly proven by the researches of Neufeld, Curschmann, and 

 Richardson. 



To sum up the pathology of typhoid fever we have in it a 

 disease, the centre of which lies in the lymphoid tissue in and 

 connected with the intestine. In this situation we must have an 

 irritant, against which the inflammatory reaction is set up, and 



