COPROZOIC AMCEB^ 257 



disappear, though some observers, such as Rogers, chiini that it will. 

 The writer with O'Connor observed a case in Egypt of a liver abscess 

 which was draining after operation. Active amoebae were constantly 

 present in the pus in spite of the administration of large doses of emetine 

 both subcutaneously, by the mouth, and by injection into the abscess 

 cavity. Here it would seem that failure of the emetine to reach the tissues 

 in which the amoebse were actually living, possibly as a result of defective 

 circulation, would account for the residt. 



The action of emetine in getting rid of infection of 7. butschlii 

 was first noted by the writer and O'Connor (1917) in Egypt. The same 

 result was obtained by others, as recorded by Dobell, Gettings, Jepps, 

 and Stephens (1918). If it is correct that emetine only acts on E. histo- 

 lytica indirectly by its influence on the tissues of the host, and has no 

 action on E. coli and other intestinal amoebae, it is difficult to understand 

 how it affects I. butschlii, which, as far as we know% is similar in habits to 

 E. coli. 



In some cases of E. histolytica infections emetine fails to act, and in 

 these it can only be supposed that the intestine is in such a condition that 

 the tissues in which the amoebae are living are not reached by the emetine, 

 possibly as the result of defective circulation in certain portions of semi- 

 necrotic mucosa. The view that emetine resistant strains of E. histolytica 

 exist requires definite proof, of which at present there is none, before 

 it can be accepted. There also does not seem to be any evidence that 

 the administration of emetine wall cause a sudden encystment of amoebae 

 in the gut, as has been claimed. When it is understood that encystment 

 is not a simple process, but depends first of all on the production of pre- 

 cystic amoebae, it is difficult to see how this can be brought about in a 

 short time. It is possible that, if precystic amoebae are present at the 

 time of administration of emetine, this might accelerate their encystment. 



There is no evidence that the cases which resist emetine do so on 

 account of the presence of cysts. Certain resistant cases, as noted by 

 the writer and O'Connor (1917), appear never to pass cysts, free active 

 amoebae alone being found in the stools whenever these are examined. 



AMCEB^ CULTIVATED FROM FAECES— COPROZOIC AMCEB^. 



The fact that amoebae develop in faeces after they have been passed, 

 and on the surface of agar plates inoculated with f^ces, has misled ob- 

 servers into believing that they had been able to cultivate the intestinal 

 amoebae. Kartulis (1891) claimed to have cultivated amoebae of the 

 human intestine, but it was pointed out by Celli and Fiocca (1894, 1895), 

 and Casagrandi and Barbagallo (1895, 1897), that the cultures contained 



I. 17 



