DOUBTFUL AMOEBOID ORGANISMS 139 



To my mind it seems probable that they are merely large cells in the 

 organs studied. It seems premature to discuss the systematic position 

 of this amoeba, therefore, before we know that it really is one. 



It is difficult to understand how infection takes place if " E. mortina- 

 ialiiim" really is an amoeba. Smith and Weidman (1914) consider that in 

 both their cases the mother was primarily infected, and the child acquired 

 its infection " from some as yet unknown focus in her." " Doubtless," 

 they say, "the parasites are harmless for the adult mother; while for the 

 fetus, especially when impaired by luetic taint, they may well prove 

 pathogenic and capable of destroying life." Doubtless : but one would 

 like some evidence before accepting these speculations as facts. For the 

 present it will suffice to notice that *' E. rnortinataHiim" differs radically 

 from all species of amoebae proved to occur in man. 



" Entamoeba polecki Prowazek, 191 2." — Most of the species of 

 Entamoeba described at various times by Prowazek have already been 

 identified : but there remains one of his species which has not yet been 

 mentioned. This is an organism — or organisms — which he named 

 " Entamoeba polecki " (Prowazek, 191 2). It has been justly remarked by 

 James (1914) that "this writer worked with very insufficient material" : 

 and the present species forms no exception. James, indeed, even doubts 

 whether the name " E. polecki'' was really given to "entamoebae or 

 something else." 



In a very brief note Prowazek (1912) states that he found the 

 organism in a pig, and also in the stools of a child, in Saipan (Ladrone 

 Islands). It is said to be " 10-12 fi large " ; and it is stated further that 

 in " older faeces " amoebae measuring only 5 /x, were also observed, which 

 copulate in pairs and encyst. A few figures are given, but they are 

 difficult to interpret. There is nothing to show that this " species " is 

 not a mixture of amoebae* from pigs and human beings confused with 

 free-living species from stale human stools. 



In view of the astonishing habitat and development ascribed to this 

 organism, the absence of evidence in support of Prowazek's statements, 

 and the fact that no recognizable description has yet been published, I 

 consider that " E. polecki " is a species which should be rejected. 



'^Entamoeba dysenteriae enropeae Popper, 1917." — Under this name 

 another " new amoeba " has recently been described by Popper (1917). 

 It was found in the stools of patients suffering from dysentery in Galicia 

 and Hungary. Although it is described at length, it is impossible to 

 recognize, in the description, anything which greatly resembles an 

 amoeba. Most of the cytological characters necessary for its determina- 

 tion are not recorded ; and the account shows such obvious ignorance 

 of amoebae generally, and of the intestinal amoebae of man in particular, 

 that it can hardly be doubted that Popper's "new amoeba" is really 

 a mixture of cells — and possibly other bodies— from dysenteric stools. 

 I shall not discuss this " organism " further. But I may note the following 

 as samples of the author's observations, and in justification of my 

 rejection of this species. " E. dysenteriae enropeae " is a " colourless cell " 



* I note that Brumpt (1913) and Pestana (1917) regard '' E. polecki'' as a svnonym 

 of £". coli^ and that Hartmann (1913) retains it as an independent species. Neither of 

 these views appears to me justifiable. 



