PROTOZOA IN THE DIGESTIVE TRACT 



23 



nucleus, is typically surrounded by small spherules that 

 do not take stains so that the achromatic interspherule 

 substance may appear as a reticulum (Fig. 4, 3). There 



»|jwr^ 





\ 



4 



■■> 



6 7 9 10 



Fig. 4. lodamoeba biitschlii. X 1150. (original) 



1. A living amoeba. 



2-5. Stained amoebae. 



4, 5. Somewhat degenerated trophozoites. 



6. A fresh cyst. 



7-10. Stained cysts. 



may be small chromatin granules in this area. The endo- 

 some is found in various parts of the nucleus, and may 

 stain homogeneously or show a more deeply stained corti- 

 cal layer. The well developed nuclear membrane is free 

 from chromatin granules. 



Cysts 



1. Living specimens. Although spherical cysts occur, the 

 majority are ovoid, ellipsoid, triangular, pyriform, or square 



