PARASITIC AMCEB^E OF MAN. 



capable of penetrating soft tissues and Schaudinn 

 claims that it is owing to this property that these 

 organisms push their way into the intestinal wall. He 

 says: 



" The harmless Ent amoeba coU with its soft pseu- 

 dopodia is unable to penetrate the healthy epithelial 

 layer of the intestine, while the dysentery amoeba by 

 means of its tough ectoplasm can do so. This is 

 easily observable upon fresh sections of infected cat 

 intestines in which the amoebae will crawl about for 

 hours, forcing the cells of the epithelium asunder, 

 thus working their way into the tissues." 



One has but to compare the firm appearance and 

 well defined ectoplasm of Entamceba histolytica with 

 the delicate ectoplasm of Entamceba coli to be con- 

 vinced of the truth of Schaudinn's arid Jiirgens's as- 

 sertion that the secret of the pathogenic action of 

 Entamceba histolytica lies partly in the ability of the 

 ectoplasm to penetrate the mucous membrane of the 

 intestine, a property not possessed by the ectoplasm 

 of Entamceba coli because of its delicate structure. 



The endoplasm, which comprises about two-thirds 

 of the body of the amoeba, is light grayish in color 

 and is composed of granular material enclosed within 

 an ill-defined reticular structure. It is much coarser 

 than the ectoplasm and less refractile. 



Inclosed within the endoplasm there are generally 



