AMOEBINA 317 



E. gingivalis (Gros) {E. huccalis Prowazek) (Fig. 145, i-k). 

 Fairly active amoeba; a few lobopodia are formed and retracted 

 rapidly; 10-40ju long, the majority measuring 10-20^1 in diame- 

 ter; cytoplasm distinctly differentiated; endoplasm with host tis- 

 sue cells, bacteria, etc.; nucleus similar to that of E. histolytica, 

 but endosome not always central; multiplication by binary fis- 

 sion; cyst is unknown, and therefore transmission of the amoeba 

 from man to man is considered to be direct. 



This amoeba is the first endoparasitic amoeba known to man 

 and was observed by Gros in 1849 in human tartar. As to the ef- 

 fect of the amoeba upon the host, some workers believe that it is 

 the probable cause of pyorrhoea alveolaris, while the majority of 

 investigators are inclined to think that it is a commensal of the 

 human mouth. 



E. gedoelsti Hsiung (E. intestinalis (Gedoelst)). In colon and 

 caecum of horse; 6-13^ by 6-11^; endomsome eccentric; bacteria- 

 feeder. 



E. equi Fantham. 40-50/u by 23-29ju; nucleus oval; cysts tetra- 

 nucleate, 15-24/x in diameter; seen in the faeces of horse; Fan- 

 tham reports that the endoplasm contained erythrocytes. 



E. hovis Liebetanz. 5-20^ in diameter; in stomach of cattle. 



E. ovis Swellengrebel. Cyst uninucleate; in intestine of sheep. 



E. caprae Fantham. In goat intestine. 



E. polecki (Prowazek). In colon of pigs; 10-12yu in diameter; 

 cyst uninucleate. 



E. debliecki Nieschulz. In intestine of pig; S-lOju in diameter; 

 cyst uninucleate. 



E. venaticum Darling. In colon of dog; similar to E. histolytica; 

 since the dog is experimentally infected with the latter, this 

 amoeba discovered from spontaneous amoebic dysentery cases 

 of dogs, in one of which was noted abscesses of liver, is probably 

 E. histolytica. 



E. cuniculi Brug. Similar to E. coli in both trophic and en- 

 cysted stages; in intestine of rabbits. 



E. cohayae Walker (E. caviae Chatton). Similar to E. coli; in 

 intestine of guinea-pigs. 



E. muris (Grassi). Similar to E. coli; in intestine of rats and 

 mice. 



E. gallinarum Tyzzer. In fowls intestine; cysts octonucleate. 



E. testudinis Hartmann. In intestine of turtles, Testudo graeca, 

 T. argentina, T. calcarata and Terrapene Carolina. 



