E. histolytica infection acquired in England ; but at the time it 

 appeared probable — as Wenyon inferred — that the patient had 

 contracted his infection ' from material from some carrier case 

 who had been at the dock or on the transport '.• 



The second case was one which has been recorded by Dr. G. 0. 

 Low and myself (Low and Dobell (1916), Case 3). The subject 

 was a young man who attended my class, in 1916, for instruction 

 in the routine examination of stools, in order to take up the work 

 of diagnosis at a military hospital. Like the other members of 

 the class, he subjected his own stools to careful microscopic 

 examination, and was surprised to find that he was passing cysts 

 of E. histolytica — an observation which I was able to confirm. 

 This worker had never at any time suffered from dysentery, 

 persistent diarrhoea, or other intestinal disorder, and displayed 

 no symptoms of intestinal disturbance at the time of the dis- 

 covery. He had, however, been abroad— to Switzerland, Southern 

 France, and Northern Italy — though never in the tropics or in 

 any places where amoebic disorders were known to be prevalent, 

 and had resided in England for the preceding five years. It 

 seemed probable, at the time, that he had accidentally acquired 

 his infection in the laboratory, \n the course of examining stools 

 containing cysts of E. histolytica. Two circumstances, however, 

 led me to doubt the correctness of this supposition. In the first 

 place, this worker was particularly careful and cleanly in his 

 work — in fact, so fastidious, owing to his natural repugnance to 

 handling stools, that he seemed the least likely of any member of 

 the whole class to acquire an infection accidentally. The second 

 point was this : he was infected with a race of E. histolytica 

 forming cysts of unusually large size,^ and — so far as I could 

 ascertain at the time — no sample of faeces containing similar 

 cysts had been examined by him whilst he was working with me. 

 I am now inclined to believe that in this case the infection was 

 really not acquired in the laboratory, but that the subject was a 

 contact carrier who had unknowingly been infected for some 

 years at least, and had contracted his infection very pTobably in 

 the British Isles. 



There is one other case which became known at about the 

 same time and which ought, perhaps, to be placed in the same 

 class as the two just mentioned. This is the case recorded by 

 Worster-Drought and Eosewarne (1916). The patient was a 

 soldier who had never left England, but had lived all his life in 

 or near Manchester. He enlisted in 1915, and was admitted to 

 the Royal Herbert Hospital, Woolwich, in the following year, 

 with a typical attack of acute amoebic dysentery. E. histolytica 

 was found in his stools ; and he recovered rapidly, and apparently 

 completely, as a result of emetine treatment. No carriers of 

 E. histolytica could be found among this patient's companions ; 

 but whilst it is certain that he was a case of amoebic dysentery 



^ That the cysts were those of E. histolytica there can be no question : and con- 

 firmation — if it were needed — is supplied by the fact that the infection was entirely 

 eradicated by treatment with emetine bismuth iodide. 



