AMOEBA OF THE INTESTINAL TRACT. 



one or more vacuoles, non-contractile in character. In 

 some of the larger parasites these vacuoles are very 

 numerous, and such organisms are probably degen- 

 erating. Besides the vacuoles, small oval bodies are 

 often observed, the nature of which is still in doubt, 

 although they are generally interpreted as being the 

 nuclear portion of the spores which bud from the 

 organism. Red blood corpuscles, crystals, and bac- 

 teria are generally observed lying within the endo- 

 plasm. 



The Nucleus. It is generally difficult to dis- 

 tinguish a nucleus in this species, a fact which serves 

 to assist in differentiating it from Entamceba coti, the 

 nucleus in the latter being visible in nearly every 

 organism as a distinct body possessing a well marked 

 nuclear membrane, masses of chromatin and a definite 

 karyosome. The nucleus of Entamceba histolytica is 

 generally situated excentrically in the endoplasm, 

 often near the boundary of the ecto- and the endo- 

 plasm, or it may be in contact with the border of the 

 ectoplasm, being flattened out against- it. The size 

 varies with the stage of growth of the parasite, but it 

 averages about 5 microns in diameter. When the 

 organism is moving the nucleus continually changes 

 its position and it is exceedingly difficult to study it at 

 this time, owing to its continual disappearing from 

 view within the endoplasm. 



