418 



PROTOZOOLOGY 



Fig. 190. 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, chromo- 

 somes reduced in number from 12 to 6; p, q, development of sporo- 

 blasts, each of which develops into a spore with three sporozoites. 



schizogony cytomeres first appear and then merozoites; altera- 

 tion of generations and of hosts which are marine annelids, mol- 

 luscs and crustaceans. 



Genus Aggregata Frenzel. Schizogony in a crustacean and 

 sporogony in a cephalopod; zygote produces many spores, each 

 with 3 sporozoites. Many species. 



