THE MASTIGOPHORA 



133 



Pringsheim regards the larger ones as females, while the smaller ones 

 may be either male or female. 



Fig. 75. Cercomonas crassicauda Duj. [DALLINGER and DRYSDALE.] 

 A. Ordinary forms. B. Division stage. C. Conjugation of two individuals in amoeboid con- 

 dition. D-E. The copula. F. Sporulation. 



The fused mass (zygospore) encysts and dries, the color changing 

 from green to red. When remoistened, the contents again turn green 

 and break open the cyst, usually as a single swarm-spore, although 



