AMOEBAE OF THE INTESTINAL TRACT. 



When motionless no distinction can be made be- 

 tween the ecto- and endoplasm, but when moving, 

 even in the smallest amoebse, these two divisions of 

 the cytoplasm can be easily distinguished, the endo- 

 plasm being more refractive than the ectoplasm and 

 apparently of greater consistence. The endoplasm 

 comprises about three-fourths of the substance of 

 the parasite and is finely granular in structure, while 

 the ectoplasm appears homogeneous in structure and 

 of very slight consistence. The endoplasm may con- 

 tain bacteria, diatoms, crystals, and occasionally one 

 or more red blood corpuscles. 



The greater degree of refraction of the endo- 

 plasm of Paramceba hominis, as compared with the 

 ectoplasm, serves to distinguish the amoebic stage of 

 this parasite from Entamceba histolytica and Enta- 

 mceba tetragena, in which the ectoplasm is more re- 

 fractive than the endoplasm; and from Entamceba 

 coli, in which there is practically no distinction be- 

 tween the ecto- and endoplasm. 



The nucleus can be easily distinguished in even 

 the smallest amoebse ; it is a refractive, spherical body, 

 surrounded by a rather thick, very refractive, granu- 

 lar nuclear membrane, which in the larger organisms 

 appears to be composed of brightly refractive rods 

 arranged end-to-end around the periphery of the less 

 refractive nuclear substance, or of large granules 



