40 



amoebae may also be seen in the blood vessels and lymph spaces. 

 As the process progresses and as the lesions become more advanced 

 the effect upon the submucosa is more marked. The congestion i? 

 augmented, the edema is increased and the number of amoebae is 

 greater. There is usually also an increase in the mucoid changes 

 of the epithelium surrounding the lesion. In a few cases we have 

 seen a very low, atrophic mucous membrane and a comparatively 

 thin-walled gut, although there were extensive ulcerations. It is 

 reasonable to suppose that we were dealing in such cases with an 

 infection of a bowel previously the seat of a chronic enteritis. In 

 all the cases we have studied, regardless of the state of the mucous 

 membrane or submucosa, we have seen an extensive lymphoid cell 

 infiltration and at least a moderate hypertrophy of the lymphoid 

 apparatus. 



In all lesions, whether early or late, the character of the cellular 

 infiltration is the same in uncomplicated cases. It seems, if 

 amoebae can be demonstrated in the tissues and if at the same 

 time there is a pohniiorphonuclear infiltration, that bacteria are 

 playing an active part in the process, especially if with the infil- 

 tration there is an}* degree of nuclear fragmentation. In certain 

 cases infiltration with pol}Tnorphous leucocytes may be seen 

 about the margins of the ulcers, although at the base of the 

 lesions and in the submucosa they were present in but inconsid- 

 erable numbers. In some cases, although there were some or even 

 many, bacteria present, there was no process which seemed to be 

 directly attributable to these. It is possible that in such cases 

 these were simply the nonpathogenic, harmless commensals of 

 the amoebse. In others, bacteria seemed to play at least as 

 important a role as the amoebae, noticeably in those in which 

 there was diphtheritis and gangrene. It may be that the bacteria 

 play an important part in determining whether or not hemor- 

 rhages shall occur, for it is certain that in uncomplicated cases 

 thrombosis is a common and early occurrence. In many very 

 early stages the interglandular vessels of the submucosa may 

 be seen generally thrombosed. If an ulcer is filled with a 

 diphtheritic slough which is carried away suddenly, the chances of 

 the hemorrhages are much increased, as is the case in typhoid. 



Usually the necrotic process extends for some distance beyond 

 the ulceration and often beyond the amoeba, but in many instances 

 amoebae seem to be present in healthy tissue, notably in the early 



