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University of Calif ornm Publicaiions in Zoology [Vol. 20 



in providing a structural and functional basis for the persistence of 

 infections by these two tlagellates during and after palliative treat- 

 ment. 



The dimensions of the active flagellate are quite variable, both in 

 size and in extension. Twenty active individuals averaged 19.6/i in 

 length, with a range of 13 to 24/x. Stained flagellates range from 9.6 



Fig. A. CMlom-astix mesnili (Wenyon). Normal flagellate viewed from the 

 ventral or oral side and showing all the structures of the body. X 6370. 



Fig. B. Cyst of Chilomagtix mesnili, viewed from the ventral or oral side. 

 X 6370. 



Abbreviations: cent., centrosome; cent, k., central karyosome; cyst, cyst wall; 

 oyt., cytostome ; cyt. f,., eytostomal flagellum or undulating membrane ; int. rhiz., 

 intranuclear rhizoplast; I. a. fl., left anterior flagella; nuo., nucleus; n-iu}. rhiz., 

 nuclear rhizoplast; par. b., parabasal body; purast., parastyle; perist. f., peri- 

 stomal fiber; prim, hleph., primary blepharoplast ; r. a. fl., right anterior flagellum; 

 seo. bleph., secondary blepharoplast; spir. gr., spiral groove; tert. bleph., tertiary 

 blepharoplast; tr. rhiz., transverse rhizoplast. 



