45 



Relation of the ama'ha' to the tissues. — The mucous membrane: 

 It is not known whether the amoebaa are able to attack or pass 

 through an intact mucous membrane ; in fact, it seems probable that 

 in order for them to enter the deeper layers of the intestine there 

 is some change from the normal (Schaudin). It is possible that 

 catarrhal conditions, however slight, are accompanied by erosion, 

 or necrosis of even a few of the superficial cells, and would offer 

 the necessary conditions for invasion. It is at any rate certain 

 that the amoebae have less influence on the epithelial cells than on 

 the supporting tissue in many glands. That this is true may be 

 demonstrated repeatedly. The amoebse may be seen either in the 

 lumen or between the lining cells and the basement membrane. 

 As a rule in these cases the epithelium detached has lost no more 

 of its normal character than might be expected, and if adherent it 

 seems more healthy than w^ould be imagined in the presence of an 

 organism whose power of causing cellular destruction is as great as 

 it is in the case of the amreba. Generally speaking, epithelium 

 seems to have as great resistence to the amoeba as has muscular 

 tissue. 



^luscle : In all works on amoebiasis attention has been called to 

 the lack of resistance the connective tissue offers to the progress of 

 the organisms. Attention has been repeatedly called to the fact 

 that the extensive ulcerations are in form and situation dependent 

 upon this quality in the submucosal layer of the intestinal wall. 

 The priliminary feature of the changes in this position is oedema, 

 which, after invasion by the amcebse, is followed by swelling of 

 the fibers and cells, infiltration wdth round cells, and lymphocytes, 

 sometimes accompanied by fibrin formation. The nuclei of the 

 swollen cells become paler, the appearance of fibrillation is lost, and 

 the tissue becomes hyaline or necrobiotic. A further feature of the 

 process is that new tissue is found early and this has the appearance 

 of granulation tissue. Suppuration, as previously indicated, prob- 

 ably does not occur in the uncomplicated disease. 



Blood vessels : Just how the organisms enter the blood vessels 

 can not be satisfactorily stated. In some sections they are seen 

 in large nvmibers, in the same or others they may be in the peri- 

 vascular lymph spaces, or they may appear immediately beside 

 the endothelium of the capillaries. It is possible that they enter 

 directly through the capillary walls liy virtue of tlicir inherent 



