VEGETABLE ORGANISMS IN HUMAN FECES 37 



F. Some Vegetable Organisms in Human Feces 



There are many bodies that occur in human feces that 

 may be mistaken for the motile stages or cysts of Protozoa. 

 Of these the most confusing are probably the vegetable 

 organisms known as Blastocystis hominis, and the yeasts. 



1. Blastocystis hominis (Plate III, Fig. 8). This organism 

 is frequently found in stools containing intestinal Protozoa 

 and often occurs when Protozoa are absent. It is usually 

 spheroidal in shape and very variable in size, ranging from 

 3 to 20 microns in diameter. The smaller specimens are 

 often oval, with granular contents that stain yellow in 

 iodin-eosin stain, and with a peripheral film of pink. They 

 may easily be confused with Endolimax nana. The large 

 specimens possess a refractive homogeneous center and an 

 outer granular coat which contains refractive granules and 

 stains pink in iodin-eosin stain. 



2. Intestinal yeasts (Plate III, Fig. 9). Certain yeasts 

 are normally present in human feces and may be mistaken 

 for protozoan cysts. In the iodin-eosin stain they take on 

 a red color at once which is sufficient to distinguish them 

 from protozoan cysts. Some of them also are found in the 

 process of budding. Other cyst-like bodies also occur in 

 human feces; these may be degenerating organisms, or the 

 spores of molds (Plate III, Fig. 10). Certain of these may 

 correspond to what Wenyon and others have called "iodine 

 cysts;" bodies that have been identified by Dobell as belong- 

 ing to an amoeba to which the name lodamoeba butschlii 

 has been given. 



