AMCEBJE OF THE INTESTINAL TRACT. 



by the existence of a non-pathogenic species, Enta- 

 mceba coll; that experiments upon animals are re- 

 liable provided they are properly controlled; that 

 direct infection of susceptible animals has been 

 abundantly proven; and that the argument that the 

 pathogenic species have not been cultivated is not a 

 valid one as disproving their relation to dysentery, 

 as many other organisms undoubtedly connected with 

 disease have not been cultivated. 



In support of the causative relation of certain 

 species of amoebae to dysentery we have the following 

 facts: 



1. The absolutely characteristic pathology of 

 amoebic dysentery. 



2. The constant presence of the pathogenic 

 species in the characteristic lesions and their absence 

 from the lesions of other kinds of dysentery. 



3. The constant presence of the amoebae in the 

 peculiar form of abscess of the liver complicating 

 amoebic dysentery. 



4. The experimental production by feeding and 

 inoculation experiments, of a disease in susceptible 

 animals presenting the same pathological lesions as 

 those of human amoebic dysentery. 



The evidence mentioned above applies in the case 

 of Entamceba histolytica and Entamceba tetragena, 

 the two pathogenic species which had been thoroughly 



