186 



University of Calif ornia Publications in Zoology [Vol. 20 



DISTINCTIONS BETWEEN COUNCILMANIA LAPLEVRI AND 

 ENDAMOEBA COLI 



Since these two species both have eight-nucleated cysts the number 

 of nuclei can not be utilized to separate the two infections as in the 

 case of the separation of E. dysenteriae from the two species under 

 discussion. There is, however, a group of characteristics which may 

 serve in the critical diagnoses of infections by Cmincilmania. The 

 most reliable one, the distribution of the chromatin in the nucleus, is 

 fortunately most evident in the commonest stages, the eight-nucleate 

 cyst. The available diagnostic characteristics are set forth below. 



Councilmania lafleuri 



Endamoeha coli 



Very active, pseudopodia thrust out 

 suddenly, ectoplasm sharply separ- 

 ated from endoplasm. 



Red blood corpuscles ingested readily. 



Peripheral chromatin in a thin layer, 

 karyosome large, excentric, with 

 halo, or often seen in premitotic 

 condition with chromatin dispersed 

 in granules in a sphere, ring, or 

 skein, without halo and often central. 



Sluggish, ectoplasm not sharply sep- 

 arated from endoplasm. 



Red blood corpuscles not ingested 

 normally. 



Peripheral chromatin in a thicker 

 layer, karyosome small, spherical, 

 with halo, generally excentric. 



Encysted Stage 



Cyst wall very thick. 



Spheroidal, ellipsoidal or asymmetri- 

 cal, less often spherical. 



Less readily stained. 



Glycogen body more resistant to iodine. 



Nuclei with little peripheral chroma- 

 tin and large, generally central or 

 but slightly excentric, dispersed 

 karyosome. 



Chromatoidal bodies less acicular in 

 early stages, fasciculate, massed 

 centrally in later stages and con- 

 tributing to chromophile buds. 



Chromophile ridge forms a bud through 

 a pore in the cyst wall, which de- 

 taches uninucleate amoebulae. 



Cyst wall thin. 



Generally spherical. 



More readily stained. 



Glycogen body stains readily in iodine. 



Nuclei with more peripheral chroma- 

 tin and small, excentric, massed 

 karyosome. 



Chromatoidal bodies more distinctly 

 acicular, with less central massing 

 and no relation to segregation of 

 chromophile cytoplasm. 



Budding unknown. 



