PARASITES AND DISEASE (VEGETABLE PARASITES) 165 



testines. The swollen follicles may undergo resolution 

 or the process may go on to necrosis and sloughing. 

 This is due in part to a choking and obliteration of the 

 blood-vessels by the infiltration, and in part to the direct 

 action of the bacilli upon the cells. Following and de- 

 pendent upon the sloughing there occurs ulceration. 

 The necrotic tissue gradually separates, beginning at 

 the periphery of the gland, finally becoming detached and 

 leaving ulcers of varying sizes and depths. Upon the 

 separation of the slough, cicatrization begins. The 

 ulcers diminish in size, the floor becoming covered with 

 a layer of delicate granulations. The mucosa gradually 

 extends in from the edge, and a new growth of epithelium 

 is formed. The mesenteric glands are infiltrated, en- 

 larged, and softened, but seldom suppurate. The 

 spleen is enlarged and softened, and parenchyma tous 

 degeneration may occur in all the tissues of the body- 

 kidneys, liver, heart, blood-vessels, nervous system, 

 and bone-marrow. 



Morbid Physiology. In addition to interference with 

 the function of the intestines by the local manifesta- 

 tions of the disease, the toxin produces widespread dis- 

 turbances in other organs. Changes occur in the 

 blood, with an increase of the agglutinins, giving rise 

 to the Widal reaction, with, finally, the establishment of 

 immunity. The fever, apathy, delirium, and the various 

 parenchymatous degenerations are doubtless due to the 

 toxin. 



