PLATE 16 



Fig. 7. Encysted Chilomastix showing tlie typical pyriform cyst with its wall 

 at the anterior end thickened. 



Pig. 8. Spheroidal cyst with large chromatoidal bodies near the parabasal 

 and parastyle. 



Fig. 9. Cyst viewed from the aboral side. The body within the cyst has 

 become inverted with the anterior end at the large end of the cyst. 



Fig. 10. Cyst showing normal appearance of encysted flagellate. Spiral 

 groove shown as clear line on the right side. Parabasal exposed within the cyto- 

 stome. 



Fig. 11. Ovoidal cyst containing numerous chromatoidal bodies in cytoplasm. 

 Body inverted within the cyst. 



Fig. 12. Subspheroidal cyst. 



Fig. 13. Prophase of mitosis. Centrosome, blepharoplasts and rhizoplasts 

 have divided, and the new cytostome with parabasal and parastyle has appeared. 



Fig. 14. Prophase of mitosis. A slightly later stage with the cytostome en- 

 larging. 



Fig. 15. A still later stage of the prophase, with the new cytostome fully 

 developed and the chromatin of the nucleus beginning its reorganization for 

 mitosis. 



1 142 J 



