184 PARASITIC AMCEBJS OF MAN. 



from that composing the endoplasm. The ectoplasm 

 is hyaline in appearance and resembles that of Enta- 

 mceba histolytica, being very refractile and glass- 

 like. I have not been able to distinguish any differ- 

 ence in the appearance of the ectoplasm of this species 

 and that of histolytica. Under high power the 

 ectoplasm appears to be composed of multitudes of 

 minute granules suspended in a homogeneous plastic 

 substance. 



The endoplasm of this species has a grayish ap- 

 pearance and in the fully developed organism ap- 

 pears to be composed of various sized granules and 

 contains within it bacteria, crystals, and in most in- 

 stances, one or more vacuoles. In this species the 

 number of vacuoles is not as great as in Entamceba 

 histolytica, and not infrequently organisms are 

 observed in which no vacuoles are present. The 

 vacuoles are not contractile so far as I have been 

 able to observe. 



The Nucleus. The nucleus of this species is one 

 of its most characteristic features. It is compara- 

 tively large and is always well defined. The struct- 

 ure may be described as follows: Externally there 

 is a well marked nuclear membrane, sharply dis- 

 tinguished from the endoplasm, and very refractile; 

 internally there is a large amount of chromatin situ- 

 ated upon the inner side of the nuclear membrane 



