FIG. 32. Monocystis, a SPOROZOON parasitic in the seminal vesicle of the 

 earthworm. A, the eight sporozoites (spz) escaping from the sporocyst. B, 

 a young trophozoite (tr) among the sperm-mother cells (sp) of the earthworm. 

 C, a free individual with a few withered sperm cells adhering to it. D, a mature 

 individual attached to the sperm-funnel (sf) of the earthworm. E, two mature 

 individuals joined side by side. F, two individuals have formed a cyst; en, 

 endocyst; ep, epicyst; n, nucleus. G, gametes (gam) formed by one individual 

 within the cyst. H, conjugation of gametes to form zygotes (zy). I, zygotes 

 that have secreted spore coat or sporocysts and have become sporoblasts (sp). 

 J, a single sporoblast in which the nucleus has divided, forming eight daughter 

 nuclei. K, a fully developed sporocyst containing eight sporozoites (spz). 

 (From Bourne, after Cuenot and Bourne.) 



