ENTAMOEBA HISTOLYTICA 21 



ment of Archangel, to look for work in Petrograd. Here he contracted 

 dysentery, and after spending about 5 months in hospital, died from 

 an intercurrent attack of pneumonia. Losch has left descriptions of the 

 patient, the parasites, and the post mortem findings, which leave no room 

 for any doubts concerning the interpretation of his case. 



Losch's patient suffered from a persistently relapsing dysentery, with 

 bloody mucous stools in which large numbers of very active amoebae 

 were often present. They measured, when rounded, 20-30 /i as a rule, 

 though sometimes more ; and " not seldom " they contained red blood 

 corpuscles, and occasionally leucocytes and fragments of epithelial cells. 

 Their ectoplasm was clearly differentiated from their endoplasm, and 

 each amoeba possessed a vesicular nucleus with a well-defined membrane 

 and a minute central nucleolus — points which are all illustrated by good 

 figures. Attempts were made to infect 4 dogs, by mouth and rectum, 

 with fresh stools containing the parasites. One dog contracted dysentery, 

 with numerous amoebae in its evacuations, and was ultimately killed. 

 A post mortem examination showed that its large intestine v/as ulcerated, 

 amoebae being present in the ulcers and in the intestinal contents. 

 When the patient died, the autopsy revealed a similar condition of 

 ulceration in his large intestine. Losch considered that his amoebae 

 were different from any previously described, and proposed to call them 

 " Amoeba coli." Though he remained in doubt as to the precise relation 

 of the parasites to the patient's disorder, he appears to have believed that 

 they were not the primary cause of the dysentery, but acted rather as 

 mechanical irritants which prevented the healing of the dysenteric 

 ulcers originally caused by some other agency. 



Losch studied another case of amoebic dysentery later at Kieff. It 

 was recorded by Massiutin (1889), who described four other cases of 

 amoebic infection — all probably (?) infections with E. coli — and who 

 also considered that amoebae do not directly cause dysentery. The 

 "Amoeba coli" found by Grassi (1879 a), and studied by him and other 

 Italian workers subsequently, was — in all probability — wrongly identified 

 with Losch's amoeba. It was, for the most part, Entamoeba coli — not 

 E. histolytica. 



The next discovery of importance, after Losch's observations, was 

 made by Koch in 1883, though not published until a few years later 

 (Koch and Gaffky, 1887). In conducting inquiries for the Cholera 

 Commission sent to Egypt and India in 1883, Koch had occasion to make 

 post mortem examinations of 5 cases of dysentery — 2 of them compli- 

 cated with liver abscess. Sections of the intestinal ulcers of 4 of these 

 cases revealed " peculiar amoeboid structures," of variable shape and 

 "about 1^-2 times as large as white corpuscles." They were present in 

 sections only, or in material from the bases of the ulcers — never in the 

 dejecta or gut contents : and in one case they were also present in the 

 capillaries round the wail of the liver abscess. Koch appears to have 

 regarded these bodies as " amoebae," but his observations, at the time, 

 were by no means unequivocal. There can be little doubt now, how- 

 ever, that he actually observed £. histolytica, apparently for the first time, 

 in the primary lesions in the bowel and also in its secondary site of 

 infection in the liver. 



Further observations upon the occurrence of amoebae In dysentery 

 were soon recorded in Egypt by Kartulis (1885, et scq.). In his first 

 paper (1885) he described, from 6 cases, "giant amoebae ?" which do 



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