102 THE AMOEBAE LIVING IN MAN 



connexion with E. histolytica and Trichomonas, and has had other 

 remarkable and incredible characters attributed to it at different times. 



Elmassian (1909) found some small amoebae in human stools and 

 regarded them as naked forms of Chlamydophrys stercorea, which 

 Schaudinn (1903) had stated to occur in human faeces. The figures 

 (Elmassian, 1909, figs. 39, 40) apparently depict E. nana. They pro- 

 bably do not represent the rhizopod which Cienkowski (1876) called 

 Chlamydophrys, and which I have never seen in human stools. 



It seems to me probable that several of the Japanese workers have 

 also seen E. nana, but misinterpreted it. The " merozoites " of " Ent- 

 amoeba nipponica" described by Koidzumi (1909), the " young amoebae " 

 formed by the "schizogony" of E. coU, described and figured by 

 Akashi (1913), and similar forms of a " non-pathogenic tetragenous 

 amoeba" figured by Shimura (1916, 1918), probably or possibly all 

 depict E. nana. Wenyon (1912, 1913) undoubtedly saw E. nana and 

 recognized it as a distinct species (cf. Dobell and Jepps, 1917). He 

 figured a cyst later (Wenyon, 1915), but considered that it might belong 

 to the flagellate Chilomastix (" Teitaniitns ") niesnili. He found the 

 amoebae again in patients from Gallipoli (Wenyon, 19 16), and called 

 them ''Amoeba Umax"; but later, in a joint work (Wenyon and 

 O'Connor, 1917), named the species Entamoeba nana. 



As already pointed out elsewhere (Dobell and Jepps, 1917), the "free- 

 living amoebae from the human intestine" described by James (1914), 

 in Panama, were probably for the most part E. nana. This author states 

 that he saw preparations of Wenyon's amoebae, and that they were the 

 same as his own. This is probably correct; for I have also seen Wenyon's 

 original preparations, and they certainly contain E. nana. But James 

 says further that his amoebae were the same as those called " Vahl- 

 kampfia punctata Dangeard " by Chatton and Lalung-Bonnaire (1912). 

 Now these authors believed that they had found a "limax" amoeba 

 living in the intestine, and had succeeded in cultivating it. From their 

 account it seems certain that they really did cultivate "Amoeba punctata " 

 — which is Dimastigamoeba grnberi (Schardinger, 1899) Alexeieff, 19126, 

 a common free-living form which I have also cultivated from human 

 faeces, soil, and water. It has been described under many other names. 

 This organism, however, does not live in the intestine ; and moreover it 

 will not usually grow in cultures kept at the temperature of the human 

 body. It appears highly probable, therefore, that Chatton and Lalung- 

 Bonnaire were mistaken in supposing that the amoebae present in the 

 intestine of their patient were the same as those in their cultures. What 

 the intestinal forms really were it is impossible to tell from their account. 

 They may have been E. nana, but they may also have been /. biitschlii. 

 If James saw preparations of their cultivated form {'* A. pttnctata" — D. 

 grnberi), then he was also mistaken in supposing them to be identical 

 with the forms which he himself had found {E. nana). 



E. nana also appears to be the form that Craig (1913 b) saw in James's 

 preparations, and which he says was " a typical Vahlkampfia " : and a 

 similar form may have been seen by Whitmore (1913), who mentions and 

 depicts a "vegetative form of Vahlkampfia^' from a human stool. Flu 

 (1916) also found a "Vahlkampfia" which was said to live partly free and 

 partly in the intestine. Later (Flu, 1918) he appears to have come to 

 the conclusion that this was E. nana ; but he considers that this species is 

 merely a harmless "Umax amoeba adapted to a parasitic mode of life." 



