574 



PROTOZOOLOGY 



Fig. 246. The life-cycle of Aggregata eberthi (Dobell). a, a mature 

 spore; b, germination of spore; c-f, schizogony; g, a merozoite, swal- 

 lowed by Sepia; h-j, development of microgametes; k-1, development 

 of macrogamete; m, fertilization; n, o, first zygotic division, chromosomes 

 reduced in number from 12 to 6; p, q, development of sporoblasts, each of 

 which develops into a spore with three sporozoites. 



Genus Merocystis Dakin. Sporogony in the kidney of the whelk, 

 Buccinum; schizogony unknown, in another host (possibly a crab); 

 microgametocytes produce first C3^tomeres which in turn form 

 microgametes; anisogamy gives rise to zygotes, zygote forms many 

 sporoblasts, each developing into a spore; spore spherical, with 2 

 sporozoites. One species. 



M. kathae D. (Fig. 247, a, b). In the kidney of Buccinum un- 

 datum; spores spherical, about 14^ in diameter. Patten (1935) 



