COMPARATIVE STUDY OF AMCEB^. 263 



Akashi (1911) has recently described 4 species of amoebae parasitic in the 

 intestinal tract of man in Japan. Two of these are considered by this author 

 as probably identical with Entamoeba coli and Entamoeba histolytica respectively; 

 one he designates as Entamoeba tetragina, but states that he does not consider 

 it identical with the tetragina species of Viereck; and the fourth is said to 

 be a new species which the author does not designate by name. The descrip- 

 tions of these species are in Japanese with a brief abstract in German. The 

 chief point of interest in the inadequate descriptions (in German) is that re- 

 production takes place by '"schizogony" in the encysted stage in the two latter 

 species, with the formation of 4 nuclei in "Entamoeba tetragi/na" and the number 

 of niiclei not stated in Entamoeba sp. 



Musgrave and Clegg (1904) succeeded in producing a disease in monkeys 

 and man having the symptoms and lesions characteristic of amoebic dysentery , 

 by introducing into the intestinal tract of the experimental animals cultures 

 of amoebae grown in symbiosis with pure cultures of bacteria on an alkaline 

 agar medium consisting of beef extract 0.3 to 0.5, sodium chloride 0.3 to 0.5, 

 agar-agar 20.0, distilled water 1000.0, and made 1 per cent alkaline to phenolph- 

 thalein, not only from cases of amoebic dysentery but also from lettuce and from 

 the Manila water supply; and they were able, in certain cases at least, to recover 

 in cultures amoebae ft'om the experimentally infected animals. These authors, 

 therefore, concluded that any amoeba may become pathogenic when introduced 

 into the intestinal tract of man. 



Lesage (1905) cultivated an amoeba in 7 out of 30 cases of amoebic dysentery 

 on a culture medium consisting of agar which had been washed for a week in large 

 quantities of distilled water and on which the growth of bacteria was largely 

 inhibited. This amoeba presented many of the characters of Schaudinn's patho- 

 genic Entamoeba histolytica and is believed by this author to be the pathogenic 

 species. Lesage in a subsequent paper (1907) states that leucocytic extract is 

 a particularly suitable medium for the cultivation of the pathogenic amoebae. 

 This medium is prepared from the leucocytic exudate of tlie guinea pig. The 

 exudate is kept on ice for 24 hours and then centrifugated. The clear, super- 

 natant fluid is employed as the culture medium. In this medium Lesage cultivated 

 amoebae from cases of amoebic dysentery which were pathogenic. In 1908 Lesage 

 cultivated a non-pathogenic amoeba from the intestinal tract of man in the Tropics, 

 which is said to represent several varieties, and which this author considers to 

 be the non-pathogenic species of tropical countries, distinct from the non-patho- 

 genic Entamoeba coli of temperate climates, and to which he gave the name, 

 Entamoeba tropicalis. 



Walker (1908) cultivated amoebae in symbiosis with bacteria on Musgrave and 

 Clegg's medium, from tlie intestinal tracts of a large number of animals. These 

 amoebae included one species designated as Amoeba hominis from man. These 

 cultures were made post-mortem from the intestines of tlie animals and were 

 consequently believed to be true parasites. 



Gauducheau (1908) cultivated an amoeba, Entamoeba phagocytoides, from a 

 case of amoebic dysentery in Hanoi, Indo China, on ordinary agar, potato, and 

 other media inoculated with Bacillus typhosus or other bacilli. This amoeba 

 ingests red blood corpuscles, multiplies by binary and multiple fission, and pro- 

 duces spirilla-like bodies in its cytoplasm. 



Noe (1909) was able to cultivate an amoeba three times from amoebic liver- 

 abscesses and in five out of seven attempts from dysenteric stools in Indo China 

 on an agar culture medium 0.5 per cent alkaline to plienolphthalein. The same 

 species was also cultivated from the water. This amoeba differs in its morphology 



