THE GREGARINES AND COCCIDIA 



347 



(6) The body of the female sporont rounds itself off and bursts 

 the host-cell. At the same time the karyosome is expelled from 

 the nucleus (Fig. 75, p. 146 ; Fig. 152, ?,#?). It is then ripe 

 for fertilization as a complete and mature macrogamete. 



The process of gamete -formation varies considerably in its details in other 

 coccidia, though similar in all essential points to that of C. schubergi. The 

 most important difference is that in many coccidia as, for instance, in Addea 



FIG. 154. Addea ovata: association of sporonts and gamete-formation. A, The 

 two sporonts associated ; in the male ( $ ) the nucleus beginning to break 

 up into chromidia ; B the nucleus of the male sporont resolved into chro- 

 midia ; C, formation of four secondary nuclei from the chromidia ; D, in the 

 male gametocyte four microgametes are formed from the four secondary 

 nuclei of the previous stage ; in the female gamete the nucleus has taken the 

 form of a fertilization-spindle. After Dobell. 



ovata (Fig. 154) the two sporonts do not remain separate, as in G. schubergi, 

 but associate in pairs ; a small male sporont (gametocytej attaches itself to 

 the larger female form, and the gametes are then produced. In correlation 

 with this habit, a great reduction in the number of the male gametes takes 

 place, four only being produced. In Addea (Chagasia) hartmanni, Chagas 

 states that two or even four microgametocytes attach themselves to the 

 female gametocyte ; Dobell also figures attachment of two male sporonts 

 in A. ovata. 



