Protozoa Parasitic in Frogs, Part II. 



349 



contractile vacuole is clearly visible. Occasionally I have 

 observed an individual which has lost its usual form, but is still 

 projecting pseudopodia. There is no indication of the differen- 

 tiation into anterior and posterior parts left, the body being 

 roughly rounded. The pseudopodia are round and large, and are 

 thrust out rapidly, but there is no locomotion. The contents 

 are propelled suddenly into these pseudopodia as they arise 

 (text figure 2). 



This may be an abnormality. Plate LXXI., Fig, 7, represents 

 an individual killed in osmic vapour, showing two nuclei at the 

 front end, one of which is slightly larger than the other. It is 

 the only binucleated example I have come across. 



In naming the animal I have placed it under the genua 

 Entamoeba, w^hich consists of species which are parasitic in the 

 intestines of animals, in contrast to the genus Amoeba, which 

 is considered to contain fresh water and marine forms only. 

 Doflein (2) uses these two genera, and although Walker in 1908 

 (6) regarded the division as unwarranted, I prefer to follow 

 Doflein's classification. In Walker's paper he says: — " Casa- 

 grandi and Barbagallo in 1897 proposed the generic name of 

 Entamoeba for amoebae parasitic in the intestinal tracts of anj- 

 mals. This new genus Entamoeba has been accepted by 

 Schaudinn (1903)," He goes on to say that it seems probable 

 that tlie parasitic amoebae exhibit all degrees of pftrasitism from 

 species restricted to one host, to species that can live either in 

 various hosts or free, and because of this he thinks the genua 

 Entamoeba does not appear to have any reason for existence. 



Comparing E. morula with Grassi's species, E. ranaritm 



