40 MANUAL OF HUMAN PROTOZOA 



anterior and the pointed posterior end (Fig. 10, 2, 3). A 

 large ovoid vesicular nucleus is located near the anterior 

 end. It is characterized by a distinct membrane which sur- 

 rounds an endosome and reticulated achromatic substance 

 in which chromatin granules are suspended. Four flagella 

 arise from the blepharoplasts present near the anterior mar- 



# 



Fig. 10. Trichomonas hominis. X 1150. (original) 



1. A living trophozoite. 



2, 3. Stained trophozoites. 



gin of the nucleus. The fifth flagellum bordering the undu- 

 lating membrane also takes its origin in a blepharoplast. 

 The line of attachment of the undulating membrane is 

 marked by a fibril which is known as costa. Unlike the 

 flagellates already described, Trichomoims hominis has an 

 endoskeleton, the axostyle, which is colorless or only faintly 

 stained so that it appears a clear median line. The pos- 

 terior portion of the axostyle usually extends beyond the 

 body surface. The cvtostome is a clear crescentic area 

 along the side of the nucleus opposite the undulating mem- 

 brane. The body cytoplasm is granulated or alveolated, 

 and often contains bacteria in food vacuoles. Some ob- 

 servers noticed erythrocytes in this flagellate in bloody 



