94 RESEARCH IN PROTOZOOLOGY 



amoebae excyst. He transferred the amoebae forming hyaline pseu- 

 dopodia, producing eight nucleate-cysts and known as E. muris, 

 Grassi, 1881, and E. dccimiani, Rudovsky, 1921, to the genus 

 Councilmania and described C. muris as showing greatest disper- 

 sion of the karyosome and C. decumani as showing least dispersion 

 of the karyosome in the resting stage. 



In the light of recent experience, however, I am inclined to 

 consider C. muris and C. decumani as representing division phases 

 of the same species, and consider C decumani as a synonym of 

 C. muris. 



Another form with granular pseudopodia was noted and was 

 named Endamwba ratti. The cyst of this amoeba answered to the 

 common description oi E. coli in that the karyosome of the resting 

 nucleus was massed and excentric. 



Hegner (1926a) found no cysts of the amoeba he named E. 

 dipodomysi, but the nuclei of the trophozoites he figures resemble 

 amoebae which produce eight-nucleate cysts more than nuclei of 

 amoebae which produce four-nucleate cysts. Since this amoeba pro- 

 duced hyaline pseudopodia it appears to be more closely related to 

 C. muris than to E. ratti. E. dipodomysi should not be accepted as a 

 good species until cysts are described and until adequate animal 

 transfer experiments have been performed, proving that the host- 

 parasite relation between this and other amoebae of rats is rigid. 



The genus Councilmania is still held sub judice by some proto- 

 zoologists who consider that the hyaline pseudopodia described for 

 Councilmania and the granular pseudopodia ascribed to E. coli 

 represent mere physiological phases of the same amoeba. The dis- 

 persed condition of the karyosome, ascribed to Councilmania, is 

 also regarded by some merely as a mitotic phase of the excentric 

 massed karyosome described for E. coli. Budding, through the 

 cyst wall, previously described as a generic character for Council- 

 mania, does not appear any longer to be restricted to Councilmania, 

 for a similar phenomenon has recently been described for E. his- 

 tolytica, lodamwba, and the author has seen it in Endamoeba coli. 

 Thus, whether these buds be artifacts as Wight and Prince 

 (1927) hold, whether they represent phases of a single escaping 

 amoeba through a pore in the cyst wall as recently described in 

 detail for E. histolytica by Dobell (1928), or whether they repre- 

 sent escaping amoebulae as was originally described by Kofoid and 

 Swezy (1921), is of small consequence. The important facts are 



