DOUBTFUL AMOEBOID ORGANISMS 135 



description given. Consequently, I think all the names will have to be 

 abolished. There are also many other imperfectly described amoebae 

 recorded from stools, but fortunately most of them have not been named. 



Several different workers have cultivated amoebae from the pus of 

 liver abscesses. In every case these were free-living species, and not 

 E. histolytica — so far as can be determined from the descriptions. 

 Gauducheau (191 2) obtained his "Entamoeba pha^ocytoides" from this 

 source, and Musgrave and Clegg and others had previously obtained 

 other amoebae in a similar manner. Liston and Martin (191 1) and 

 Martin {191 1) described two species of "amoebae from liver abscesses " 

 — a "large" and a "small." Their cultures were obtained originally 

 from Wells, in India, whose paper on "Aerial contamination as a fallacy 

 in the study of amoebic infections by cultural methods" (Wells, 1911) 

 probably contains the true explanation of the origin of their organisms. 

 Liston and Martin's "small amoeba" I am unable to identify, from the 

 incomplete description. Their " large amoeba" is— as I have elsewhere 

 (1914) pointed out — a species closely related to the forms placed in the 

 genus Hartiiiannella by AlexeieiT (1912 a), of which the type is H. 

 hyalina Dangeard (= Amoeba hyaliua Dangeard, 1910). 



" Leydenia gemniipara Schaudinn, 1896." — In ascitic fluid from two 

 patients with abdominal malignant growths, Leyden and Schaudinn 

 (1896) discovered some peculiar bodies which they interpreted as 

 amoebae. To these Schaudinn gave the new name Leydenia geunni- 

 para ; but he stated subsequently (Schaudinn, 1903) that they were 

 really the naked amoeboid forms of the shelled rhizopod Chlamydophrys 

 siercorea Cienkowski (1876). This organism, according to Schaudinn, 

 lives coprozoically in human faeces, but the amoeboid forms of it may 

 be found occasionally in the intestine. "Leydenia" has been regarded 

 as a very questionable rhizopod by many workers already, and I fully 

 share their doubts. 



I have never encountered Chlamydophrys in human faeces ; and the 

 amoeboid forms, if they ever do occur in the intestine of man, must be 

 excessively uncommon. It should be remembered that Schaudinn 

 recognized only two species of amoebae in man — E. coli and E. 

 histolytica: and I suspect that his " Chlamydophrys" a.moehAe were really 

 E. nana, which occurs so commonly but which he did not know. I have 

 already pointed out that this is probably the correct interpretation of 

 the "Chlamydophrys" found by Elmassian (1909), and so far as I am 

 aware no other worker has "confirmed" Schaudinn's observation. I do 

 not doubt that Chlamydophrys may occasionally occur in stale human 

 faeces, though I have never encountered it. It certainly occurs in the 

 dung of various animals, and in sewage beds.* But that there is any 

 connexion between this organism and " Leydenia," or any of the 

 amoebae of the human bowel, I regard as highly improbable. We do 

 not know how Schaudinn convinced himself of the identity of these 

 different forms, as he adduced no evidence for his statements ; and it is 

 not to be forgotten that most of his other statements about the amoebae 

 of man were incorrect. 



I have little doubt that "Leydenia" itself was not an amoeboid 



* I have studied the organism in the faeces of frogs and toads (Dobell, 1909) : and 

 I may record that my friend the late Mr. C. H. Martin showed me, some years ago, 

 a fine culture of Chlamydophrys which he obtained in material from a sewage farm. 



