264 The Philippine Journal of Science 1913 



washings from lettuce and from the Manila water supply. These authors 

 maintained that all amoebse are, or may become, pathogenic. 



One of us (Walker, 1908) obtained in culture on Musgrave and Clegg's 

 medium an amoeba, "Amoeba hominis," from the intestinal tract of a woman 

 at necropsy which was at that time believed to be a parasitic species. No 

 tests were made of the pathogenicity of this amceba. 



Noc (1909) considers the amcebae found in dysenteric stools, in the sec- 

 tions of dysenteric intestines, and in liver abscesses to be identical with 

 an amoeba common in the drinking water in Indo China and which he has 

 cultivated on artificial media. Animal experiments with cultures from 

 both the water and the dysenteric stools gave negative results. 



Williams and Gurley (1910) produced attacks of typical bloody dysentery 

 in a kitten by feeding Amceba Umax cultivated from potato parings, while 

 a kitten fed the bacteria associated with the amoebje in culture showed no 

 symptoms. 



Greig and Wells (1911) believe that the amoeba found in the stools of 

 dysenteric patients and in the pus from liver abscesses in Bombay is not 

 Entamoeba histolytica Schaudinn, but the same species that is found in 

 Cochin China. This same amoeba, these authors state, is found in the 

 conduit water of Bombay. 



Gauducheau (1912) is of the opinion that the so-called Umax amoebas 

 are in size and structure like Amwba phagocytoides, cultivated by him in 

 1907, and found in the intestine of dysenteric cases and in water. These 

 amoeba, he says, are capable of multiplying in the intestine of animals, 

 and there can be no doubt of their parasitic nature. 



Chatton and Lalung-Bonnaire (1913) describe an amoeba {A^nceba Umax) 

 which they cultivated from a case of chronic intermittent diarrhoea and 

 which they believe to be the same as the amoeboid organism which they 

 found microscopically in the stools of the patient. 



One of us (Walker, 1911) has already determined that mor- 

 phologically the cultivable amoebae belong to the genus Amoeba 

 Ehrenberg. Species of this genus are characterized morpho- 

 logically by the more or less central position of the nucleus in the 

 resting organism, by the arrangement of the greater part of the 

 chromatin of the nucleus in a central karyosome, by the presence 

 (with rare exceptions) of a contractile vacuole, by the develop- 

 ment of mononuclear cysts ; and, biologically, by the absence of 

 schizogony in the encysted stage, by their ability to live non- 

 parasitically, and to multiply on artificial culture media (Plate 

 I, figs. 1 and 2) . 



Twenty feeding experiments have been made with cultures 

 from 11 different sources, representing 13 strains and 8 species 

 of Amoeba, as detailed in Table I. 



