210 PARASITIC AMOEBA OF MAN. 



contain blood erythrocytes may be observed within 

 the endoplasm, as this parasite is phagocytic for these 

 cells. Bacteria and other crystals occur within the 

 endoplasm as in other amoebae. 



Motility. This species is actively motile, the 

 pseudopodia being short and blunt. Koidzumi states 

 that the pseudopodia do not change their shape dur- 

 ing motion. 



Reproduction. Entamceba nipponica reproduces 

 by simple division, schizogony, and by the formation 

 of daughter amoebae within a cyst. In reproduction 

 by simple division, Koidzumi states that the nucleus 

 divides amitotically into two portions, followed by the 

 division of the cytoplasm. Simple division has been 

 observed even in the very young amoebae. 



Schizogony is initiated by the crescent or spindle 

 shaped masses of chromatin changing to spheres of 

 nearly equal size, which vary in number from six to 

 eight, and remain attached to the nuclear membrane 

 by a delicate filament. The nuclear membrane gradu- 

 ally disappears and the chromatin masses become 

 free in the cytoplasm. Each mass is then surrounded 

 by a portion of the latter and the entire organism 

 breaks up into as many young amoebae as there are 

 masses of chromatin. The young amrebae are oval 

 in shape and measure about 5 microns in diameter. 

 The cytoplasm is dense in appearance and stains 



