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ago some interesting observations were made and recorded in 

 Holland by Kuenen (1918). As practically no notice has hitherto 

 been taken of his work, I propose to summarize it here. 



Kuenen, who appears to have been unaware of the observations 

 made in this country, is already known for his careful work on 

 amoebiasis in the Dutch East Indies. Having there studied the 

 intestinal protozoa of Europeans and natives, it occurred to him, 

 on his return to Holland, that similar investigations carried out 

 at home might yield interesting results. He therefore began to 

 study the stools of certain hospital patients in Amsterdam. 

 Before long he found some who were passing cysts of E. histolytica, 

 and although some of these carriers were found — as was to be 

 expected — to be persons who had been in the tropics and there 

 suffered from dysentery, he also, to his surprise, found several 

 cases of E. histolytica infection in Dutch residents who had never 

 been abroad. The following is a short summary of the indigenous 

 cases recorded. 



Case 1. — A dock-worker. Though E. histolytica cysts were re- 

 peatedly found in his stools, he showed no sj'mptoms referable to 

 his infection during his stay in hospital. He had never been 

 abroad, but had worked on board ships plying between Holland 

 and the Indies, and had therefore very probably been in contact 

 with colonial carriers of the parasite. 



Case .2. — A military patient — a miner by calling. No in- 

 testinal symptoms could be elicited, and no history of association 

 with friends or relatives who had been in the Dutch Indies. 

 E. histolytica cysts were present in the stools. 



Case 3. — A boy of 12, from Amsterdam. He had been suffer- 

 ing from dysentery, with intermissions and relapses, for 8 months. 

 Typical E. histolytica amoebae were found in the bloody mucous 

 stools. 



Case 4. — Another boy of 12, also from Amsterdam. Had 

 suffered from diarrhoea or dysentery, with intermissions, for 

 5 months. At different times he passed typical adult, precystic, 

 and encysted forms of E. histolytica in his stools. 



The last two patients (Gases 3 and 4) had scarcely ever spent 

 a single day out of their native city. They were unrelated and 

 unacquainted with one another. The stools of all the other 

 members of their families were examined, but none of them 

 found infected with E. histolytica. The father of Case 3 had 

 spent 3 weeks in the Indies some 20 years previously ; but apart 

 from this no indications of a possible colonial contamination 

 through other members of the two families could be discovered. 

 Both patients were treated with emetine hydrochloride hypo- 

 clermically, and were cured of their symptoms but remained 

 carriers of the parasite. 



Case 5. — A married Amsterdam woman of 32. Since 18 years 

 old she had had attacks of diarrhoea, sometimes with blood and 

 mucus. Many cysts and precystic forms of E. histolytica were 

 found in her loose stools. No contact with relatives from the 

 Indies could be established. The husband and two daughters of 



