MONOCYSTIS 



53 



reserve food material. This phase in the life-history is known 

 Before as the trophozoite phase. 

 The mature trophozoite lives for a time free in the cavity of the 



B 



FIG. 21. 



Mcnocyslis. A-D, Stages in growth of trophozoite. In D the " adult " trophozoite is seen as it 

 is found free in the cavity of the seminal vesicle ; in A, B and C it is seen to be contained in the 

 interior of the sperm-morula ; E, gametocytes in cyst ; F, formation of gametes ; /i-?, details of 

 process of syngamy ; G, cyst containing pseudo-navicellae ; H, pseudo-navicella free from cyst ; 

 I, group of sporozoites free from pseudo-navicella. 



[The details of syngamy are such as have been actually observed in Monocystis. Probably the 

 whole process resembles that shown in Fig. 22 which is taken from an allied genus, Stylorhynchus.] 



