LIFE HISTORY OF PRORODON GRISEUS. 



307 





FIG. i. Whole mount drawing of Prorodon griseus to show structure, ph., phar- 

 ynx; c. v., contractile vacuole; a. p., anal pore. 



FIG. 2. Encysted forms; a., temporary cyst; b., conjugants within cyst; c., 

 escape from cyst; d., binary fission within cyst; e., cyst shell; /., individual within 

 permanent cyst. 



FIG. 3. Expanded conjugants. 



FIGS. 4, 5 AND 6. Different stages in the binary fission of free forms. 



FIG. 7. Conjugating individuals, early stage. 



FIG. 70. Early conjugation before union of conjugants is effected. 



FIGS. 8, 9 AND 10. Micronuclei in different stages of the first maturation 

 division. 



