126 THE AMOEBAE LIVING IN MAN 



no means justified by the facts given. It is important to note also that 

 the faeces were twice examined carefully (after a purgative), and no 

 amoebae were found. Equally unconvincing to me is the account of 

 " amoebae " found in the urine of a woman at Sierra Leone by Wright 

 (1917). They were usually "quiescent," and measured usually 20-25 /* 

 in diameter. Cysts "were numerous," and many had " 2 and 3 nuclei." 

 The "cysts " had a diameter of about 20 to 25 yu,. Although the author 

 states that he " is persuaded to regard the amoebae as belonging to the 

 ' histolytica ' type," I am unable to find any grounds for such per- 

 suasion : nor is the statement that the patient " responded readily to 

 specific treatment with emetine hydrochloride " likely to command 

 assent from anybody who reads the recorded details in a critical spirit. 



Finally, Aravantinos and Michailides (1918) record the finding of 

 amoebae in the urine of a Greek boy with cystitis. They are said to 

 have been active, and uninucleate ; but they are not described or figured, 

 and were not investigated cytologically. The authors consider that the 

 amoeba was not E. histolytica. The case is supposed to have been cured 

 by lavage of the bladder with an infusion of ipecacuanha. During 

 treatment " cysts " appeared in the urine, but they are not described. 

 This is another very unsatisfactory case. 



It appears to me probable that most of the cases of " urinary 

 amoebiasis " hitherto described should be rejected, since there is not 

 sufficient evidence that the " amoebae " which were found really were 

 amoebae. There is, in fact, little to indicate that the bodies were even 

 protozoa in most cases — still less that they were amoebae or that they 

 belonged to any particular species. For my own part, I have little doubt 

 that jurgens (1892), Kartulis (1893), Posner (1893), Wijnhoff (1895), 

 Macfie (1916), Chalmers and O'Farrell (1917), and Wright (1917) really 

 found cells of various sorts and mistook them for amoebae. The 

 "amoebae" of Ward, Coles and Friel (1916) and Friel (1917) are self- 

 condemned; whilst the "amoebae" of Craig (1911) and Lynn (1914) 

 cannot be discussed in the absence of all descriptions of them. The 

 "amoebae" of Aravantinos and Michailides (1918) were possibly Tricho- 

 monas vaginalis. The degenerating amoeboid forms of this flagellate 

 can, as I know from experience, be mistaken for " amoebae," and they 

 occur in the bladder and urethra of males as well as of females. It is 

 possible that some of the other " amoebae " described were also this 

 organism in reality. 



By far the most satisfactory case of urinary amoebiasis yet recorded 

 seems to me to be that of Walton (1915). I see no reason to doubt that 

 he really found amoebae, and that these were — as he believed — E. 

 histolytica. There is no reason why this parasite should not occasionally 

 occur in the urine, though infection of the urinary system must always 

 be secondary to a primary infection of the large intestine. If E. histolytica 

 is found in the urine, therefore, a concomitant infection of the bowel 

 should also be present. This was so in Walton's case ; but the absence 

 of amoebae or cysts from the stools of some of the other cases speaks 

 against the supposition that the " amoebae " in the urine really were 

 E. histolytica. It is against all analogy to suppose * that the organisms 



* This I take to be the explanation which Macfie (1916) offers to account for the 

 absence of an intestinal infection in his case. He saj's he is " inclined to believe .... 

 that this patient may at some time have unconsciously harboured amoebae in his large 

 intestine," and that they somehow " found their way .... to the neighbourhood of 

 the seminal vesicles," and so emerged by way of the urethra. 



