86 PARASITIC AMCEB.E OF MAN. 



were really cases of enteritis showing Entamoeba coll 

 in the feces. Aside from the zoological standpoint, 

 it is of great practical importance that we recognize 

 the fact that this non-pathogenic species occurs both 

 in health and disease in the intestine of man and that 

 we be able to differentiate between Entamoeba coli 

 and the pathogenic entamcebse. This is often a very 

 difficult matter when the organisms are few in num- 

 ber, and at certain stages of development, while it is 

 always true that considerable experience in the ex- 

 amination of the feces is required before such a 

 differentiation can be easily made. The exceedingly 

 superficial study that many practitioners make of 

 these parasites can never result in success in the dif- 

 ferentiation of species. 



MORPHOLOGY IN FRESH AND STAINED PREPARA- 

 TIONS. To secure living specimens of Entamaeba coli 

 it is always best to administer an ounce of magnesium 

 sulphate or a Seidlitz powder before examining the 

 feces, as this washes off the amoebae from the mucous 

 membrane and greatly facilitates their demonstration. 

 The technique employed in preparing such specimens 

 for examination has already been considered. 



Entamoeba coli consists of a mass of cytoplasm 

 containing a well-defined nucleus, and in a few in- 

 stances, one or more vacuoles. The differentiation 

 between the ectoplasm and the endoplasm is not well 



