AMOEBAE IN MONKEYS 133 



amoebic abscess of the liver. It seems probable, therefore, that they 

 harbour a non-pathogenic Entamoeba like E. colt, with an 8-nucleate 

 cyst, and a pathogenic parasite like E. histolytica, with a 4-nucleate cyst. 

 These two species, if really distinct and valid, should probably be named 

 as follows : — 



(i) Entamoeba pithcci Prowazek, 191 2, emend. 

 Syn. : 



Entamoeba pitheci Prowazek, 191 2 {pro parte). 

 Loschia legeri Mathis, 191 3. 



f Entamoeba cercopitheci Macfie, 1915 (pro parte). 

 Entamoeba legeri Mathis & Mercier, 19 17. 

 Non-pathogenic. As yet indistinguishable from E. coli. Observed 

 also by Wenyon (1908), Brumpt (1909), and Behrend (1914), but not 

 named by them. 



(2) Entamoeba mtttalli Castellani, 1908. 

 Syn. : 



Entamoeba pitheci Prowazek, 1912 {pro parte). 



Loschia sp. Chatton, 191 2, 



Loschia duboscqi Mathis, 1913. 



Entamoeba chaitoni Swellengrebel, 1914. 



Entamoeba cercopitheci Macfie, 1915 {pro parte). 

 Probably a facultatively pathogenic tissue-parasite — causing dysentery 

 and liver abscess. At present indistinguishable from £. histolytica. 

 Observed probably by Musgrave and Clegg (1904), Strong {vide Kar- 

 tulis, 1913), Noc (1909), ? Franchini (1912), Behrend (1914), and Eich- 

 horn and Gallagher (1916), but not named by any of these authors. 

 Swellengrebel's form is, perhaps, a distinct species, but this is still 

 unproved. 



I have observed the cysts of both these amoebae in the faeces of 

 MacacHS rhesus* which I examined in London in the course of my work 

 with Dr. H. H. Dale {vide Dale and Dobell, 1917). At present I am 

 unable to distinguish them from those of E. coli and E. histolytica 

 respectively, and I think it by no means impossible that the amoebae are 

 really identical with these species. If this is so, then E. pitheci Prowazek 

 (with its synonyms) becomes a synonym of E. coli (Grassi) Casagrandi et 

 Barbagallo, and E. nuttalli Castellani (with its synonyms) a synonym of 

 E. histolytica Schaudinn. At present there are not sufficient data to 

 determine this point, and the question can only be decided by further 

 observation and experiment. There is, at all events, as yet no proof that 

 monkeys harbour Enlamoebae in any way different from those of man. 



• Attempts which were made to infect two of these monkeys with E. histolytica 

 were negative. 



