GENUS: lODAMCEBA 243 



philic body the writer (1915e, 1916), who first described it, called it an 

 " iodine cyst," as its exact nature was not clear. Both the cysts and amoebae 

 were found in a case by Kuenen and Swellengrebel (1917), and Brug (1919) 

 came to the conclusion that the amoebae seen by Kuenen and Swellengrebel, 

 and which they had called " Pseudolimax," were in reality amoebae of which 

 the "iodine cyst" represented the encysted stage. Kofoid, Kornhauser 

 and Swezy (1919), and Brug (1921), believe that /. butschlii is a large 

 race of E. nana, and express the opinion that lodamceha is a synonym of 

 EndoUmax, and Boeck and Stiles (1923) support them in this conclusion. 

 It seems, however, that the genus lodamceha is much better defined than 

 these observers maintain. 



IODAM(EBA OF MAN. 



lodamoeba butschlii (Prowazek, l9l'2)—Synonijmjj. — Tlicre seems to be con- 

 siderable doubt as to the correct name of this amoeba. Prowazek (1912«) gave a very 

 brief and incomplete description of an amoeba which he saw in a child in the Caroline 

 Islands. He gave it the name Entamceba butschlii. A single cyst is figured, and if 

 it represents one of the " iodine cysts " it is evidently deformed or degenerate. D obeli 

 (1919) comes to the conclusion that Prowazek was actually describing the "iodine 

 cyst " and its amoeboid stage, and that the human parasite should therefore be known 

 as lodamoeba butschlii. It is quite evident that the figures given by Prowazek cannot 

 represent either E. coli or E. histolytica. The size of the amoebfe excludes the possi- 

 bility of its being EndoUmax, nana, and from what is now known of the intestinal 

 amoebae of man the only amoeba which Prowazek could have observed is the one now 

 under discussion. On the other hand, Brug (1921) believes that another amoeba, 

 previously described by Prowazek (1911, 1912) as Entamceba williamsi, was a mixture 

 of the "iodine cyst " and Entamoeba coli. In support of this contention he states that 

 he has examined Prowazek's original preparations, and has seen in them the iodine 

 cysts and the amoeba, an observation which has also been made by Noller (1921). 

 There can be no doubt, however, that Prowazek's description and figures were based 

 chiefly on Entamceba coli, and though some of the forms described by him may have 

 been other amoebae, the name E. williamsi must become a synonym of E. coli. The 

 fact that Brug and Xoller have found the " iodine cyst " and its amoeba in the original 

 preparations does not prove that Prowazek actually described them. Taliaferro 

 and Becker (1922) support Brug and Noller in their contention that the correct 

 specific name must be williamsi. Brug further considers that the amoebae belong 

 to the same genus as EndoUmax nana, while Kofoid, Kornhauser, and Swezy (1919) 

 concluded that they are merely large races of EndoUmax nana. Eodenhuis (1919) 

 also expressed the opinion that the amoeba belonged to the genus EndoUmax, and 

 proposed to name it EndoUmax jjileonucleatus. Cauchemez (1921) has studied this 

 organism, and, in agreement with Byumpt, comes to the conclusion that it cannot be 

 identified with either of Prowazek's amoebae, E. williamsi or E. biitschUi, and proposes 

 to name it lodamoeba wenyoni, Brumpt, 1921. This is undoubtedly incorrect, for 

 if it is necessary to reject both of Prowazek's names, the correct name will be 

 lodamoeba pileonacleata. It seems, therefore, best to consider the organism as 

 identical with Prowazek's E. butschlii, and to name it lodamoeba butschlii, as Dobell 

 (1919) has done. Kuenen and Swellengrebel (1917) used the name "Pseudolimax," 

 but not as a generic title, though Brumpt (1922) has adopted it as the generic name 

 for this amoeba, to which he refers as Pseudolimax wenyoni. 



