AMOEBAE OF THE INTESTINAL TRACT. 149 



lesions of the intestine is not known. That they are 

 able to penetrate the epithelial lining of this organ has 

 been abundantly proven by the work of Jiirgens, 

 Schaudinn, and others, and by their presence in the 

 tissues as shown in microscopic sections. It is possible 

 that they secrete a toxin which causes the initial de- 

 struction of the epithelial cells which enables them to 

 penetrate beneath the mucous membrane, and that 

 this toxin has much to do with the production of the 

 lesions in the deeper tissues, but of this we have no 

 definite proof. 



In microscopic sections of the intestine of patients 

 dying of amoebic dysentery, it may be stated that, 

 almost without exception, the amoebae are present in 

 the necrotic tissue forming the wall of the ulcers and 

 in the surrounding tissue. They are most abundant 

 in the submucous coat, but are often observed in the 

 muscular coat when the ulceration has extended to 

 that region.- When present they are always sur- 

 rounded by numerous leucocytes and other evidence 

 of inflammatory action. They are most numerous 

 in the areas which are situated nearest the region of 

 greatest degenerative changes, and it is rather rare 

 to find them in the necrotic tissue overlying the ulcers 

 or composing the edges. Amoebae may be observed 

 lying within the lymph spaces and sometimes within 

 the lymphatics and veins. When the disease has ex- 



