24 PARASITIC AMGEB^E OF MAN. 



Simple Division. This method of reproduction 

 is asexual in nature and consists of a primary division 

 of the nucleus, which may be either mitotic or amitotic 

 in character, followed by the division of the cyto- 

 plasm, two amoeba* being thus produced. This 

 method of reproduction occurs in all species of 

 amoebae, so far as is known. 



Schizogony. This method of reproduction is also 

 asexual in nature and is accomplished by the division 

 of the karyosome by primitive mitosis, after which the 

 nuclear chromatin becomes collected around the 

 nuclear membrane while the cytoplasm rids itself 

 of all foreign material. When this is completed, 

 the chromatin divides into from four to eight little 

 masses, the nuclear membrane ruptures and the 

 chromatin masses become free in the endoplasm. 

 Finally, the cytoplasm divides into as many parts 

 as there are chromatin masses, and a number of 

 daughter amoebae are thus formed. This process will 

 be described in detail in the consideration of En- 

 tamceba coli, and Entamaeba tetragena. 



Gemmation. This process of reproduction, as 

 observed in amoebae, was first described by Schaudinn 

 as occurring in Entamceba histolytica. In consists 

 in amitotic division of the nucleus, the chromatin 

 being dispersed in the cytoplasm, and collecting at 

 the periphery of the organism where it is budded off, 



