EXPLANATION OF PLATES 



All figures were drawn with camera lucida from specimens of Giardia enterica 

 from smears of human stools, fixed in hot Schaudinn 's fluid and stained with 

 iron haematoxylin by the wet film method. Magnification of all figures 3200 

 diameters. 



PLATE 23 



Fig. 1. Typical active vegetative phase viewed from dorsal surface, showing 

 axostyles, parabasals, cytostomal fibers, intra- and extranuclear rhizoplasts, centro- 

 somes, and full complement of flagella. 



Fig. 2. Obliquely lateral view of free flagellate, showing the concave, 

 sucker-like cytostome on ventral face. Note parabasal rhizoplasts extending 

 to the axostyle from the ends of the parabasals. 



Fig. 3. Ventrolateral view of active flagellate with cytostome somewhat 

 expanded. 



Fig. 4. Dorsal view. Prophase with four chromosomes within the nucleus. 



Fig. 5. Ventral view. Prophase with chromatin arranged in an axial 

 spireme; paradesmose present on nucleus at left with the daughter centrosomes 

 at its ends. Note thickened intracytoplasmic flagella. 



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