PROTOZOA IN THE DIGESTIVE TRACT 43 



]:)ecome clearly noticeable near the center of the sucking 

 disc. 



2. Stained specimens. The bilateral symmetry of the 

 flagellate is clearly revealed (Fig. 11, ^5, 4). Along the me- 

 dian line of body there are seen two parallel rods rmming 



f- 



m 



S 6 7 8 



Fig. 11. Giardia intestinalis. X 1150. (original) 



1, 2. Li\ing trophozoites in front and side views. 

 3, 4. Stained trophozoites in front and side views. 



5. A fresh cyst. 



6, 7. Stained cysts. 



8. A stained cyst in an end view. 



lengthwise. These are axostyles. Near the anterior end of 

 the axostyles, there is an ovoid nucleus on either side. The 

 two nuclei are similar in size and for the most part in 

 structure. The nuclear membrane is comparatively thick 

 and there is ordinarily one endosome in the center of the 

 nucleus. There is sometimes present a deeply staining rod- 



