220 FAMILY: AMCEBID^ 



and the production of an eight-nucleated cyst. The nucleus differs from 

 that of E. coli in that the karyosome is dispersed instead of being a com- 

 pact granule. During mitotic division of the nucleus it is claimed that 

 eight chromosomes are present in place of the six which E. coli is said to 

 possess. The most characteristic feature, however, and the one on which 

 the new genus is based, is that in the host in which the cysts are formed 

 the encysted amoeba buds off, through a pore in the cyst, eight small 

 amoebje. Associated with the pore is a deeply staining band termed 

 the chromophile ridge. As has been explained above, the exact method 

 of exit of E. coli from its cyst is not known, so that the budding process 

 cannot be held to distinguish the new genus Councilmania from Entamoeba. 

 There would be more reason to place Entamoeba gingivalis in another genus, 

 because encysted forms have never been discovered. It appears, how- 

 ever, from the description and figures, that the supposed budding process 

 through a pore is most reasonably explained as a result of rupture of the 

 cyst and the consequent extrusion, by pressure or collapse of the cyst, of 

 hernia-like portions of the cytoplasm together with the nuclei. The 

 writer has seen exactly comparable appearances in cysts of E. coli which 

 have been ruptured by pressure of the cover-glass. As the liquid beneath 

 the cover-glass evaporates the pressure on the cysts is increased, so that 

 rupture takes place and portions of cytoplasm with nuclei can be seen 

 to escape. Similar ruptured cysts are often encountered in the ordinary 

 stained preparations made by the smear method. The writer has pre- 

 parations containing ruptured cysts which may be in the two, four, or 

 eight nucleated stage (Fig. 101, 15). They contain chromatoid bodies, 

 and bear a striking resemblance to the budding cysts described by Kofoid 

 and Swezy (1921rt). Werner (1912) gave a figure of a similarly ruptured 

 cyst showing a hernial protrusion including two nuclei. Casagrandi and 

 Barbagallo (1897) figure a cyst which is supposed to illustrate the natural 

 emergence of amoebae, but it is not improbable that they were observing 

 an artificially ruptured cyst. The writer has seen in stained preparations 

 similar ruptured cysts of E. histolytica with bud-like extrusions containing 

 one of the four nuclei. In view of the work of Sellards and Theiler (1924), 

 who have shown that kittens may be infected with E. histolytica by 

 injecting material containing cysts only, it is possible that E. coli may 

 sometimes emerge from its cyst while in the large intestine, and that 

 some of the appearances of budding may be due to this. It is nevertheless 

 a fact that artificial rupture of cysts of E. coli will give rise to forms 

 which are said to be characteristic of C. lafleuri. The deeply staining 

 band called the chromophile ridge, which is supposed to have some con- 

 nection with the development of the pore, is probably an artifact in 

 many cases, the result of irregularities in staining produced by folds or 



