182 



PROTOZOOLOGY 



Fig. 78. Sexual fusion in Copromonas subtilis, X1300 (Dobell). 



tained results which seem to indicate that there is no physiological 

 or sex differentiation between the fusing gametes. In the much- 

 studied Sporozoa, for example, Plasmodium, the two gametes are 

 both morphologically and physiologically differentiated, and sexual 

 fusion always takes place between two anisogametes. 



Fig. 79. Sexual fusion in Trinema linearis, X960 (Dunkerly). a, an 

 organism in life, with the resting nucleus and two contractile vacuoles; 

 b, union of two individuals; c, fusion of the organisms in one test, sur- 

 rounded by cyst membrane; d, older cyst; e, still older cyst with a single 

 nucleus. 



