COCCIDIA 



467 



a cuttlefish, merozoites penetrate gut wall and develop into mi- 

 cro- and macro-gametocytes (h, k), and further into gametes (j-l); 

 anisogamy (m) produces zygotes; zygote nucleus contains 12 

 chromosomes which become divided into 2 groups of 6 in the first 



Fig. 217. 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. 



division (n, o); repeated nuclear division (p) forms many sporo- 

 blasts (q), each transforms itself into a spherical spore wdth 3 sporo- 

 zoites (Dobell; Naville; Belaf). 



