AMOEBAEA 221 



large glycogen vacuole which stains conspicuously with iodine. 



lodamoeha biitschli (Prowazek) ( = /. williamsi Prowazek) 

 (Fig. 87, g, h). Inhabitant of the large intestine of man. The 

 sluggish trophozoites vary in size from 9 to 13 microns. The cy- 

 toplasm is ill-defined and contains bacteria which are taken in as 

 food. The cysts are mostly of irregular shape and measure 6 to 

 15 microns in diameter. In the nucleus of the cyst, the large 

 endosome comes in contact with the nuclear membrane at one 

 point. A large iodinophilous vacuole. 



lodamoeha suis O'Connor. In the intestine of pig; widely 

 distributed. Indistinguishable from the last species. It is 

 considered by some that the pigs are probably reservoir hosts 

 of this human parasite. 



Genus Dientamoeba Jepps and Dobell. Small parasitic 

 amoeba of the large intestine of man. The number of the 

 binucleate trophozoites is often greater than that of the uni- 

 nucleate forms. The nucleus has a delicate membrane. Its 

 central endosome consists of several chromatin granules em- 

 bedded in plasmosomic substances and is connected with the 

 nuclear membrane by delicate achromatic strands. One species. 



Dientamoeba fragilis Jepps and Dobell (Fig. 87, i-k). Com- 

 mensal in the human intestine. 



Genus SchiXamoeba Davis. The nucleus of the trophozoite 

 is vesicular and without any endosome, but with chromatin 

 granules arranged along the nuclear wall. Each trophozoite 

 possesses one to many nuclei. The cyst nuclei which are formed 

 by the fragmentation of those of the trophozoite, possess a 

 large rounded chromatic endosome connected at one side with 

 the nuclear membrane by achromatic strands, in which are 

 embedded chromatin granules. Parasitic in the stomach of 

 salmonoid fish. One species. 



Schizamoeha salmonis Davis (Fig. 88, a, h). The amoeba is 

 sluggish and measures 10 to 25 microns in diameter. Multi- 

 plication by binary fission, the nuclear division being amitotic. 

 The amoeba contains from one to several nuclei. The cysts are 

 said to be usually more abundant than the trophozoites and 

 their appearance seems to be correlated with the amount of 

 available food. The cysts are spherical and measure 15 to 35 

 microns in diameter, being surrounded by a thin membrane. 



