SEX IN PROTOZOA 



TABLE IV 



Meiosis in Coccidia 



(All these reports show zygotic meiosis.) 



195 



Species 



Meiosis 



Karyolysis sp., sp. 



Haemogregarinidae 

 AdeU'o ovahi 



Adeleidae 

 AggrcgiUa ehcrthi 



Aggregatidae 

 Klossia helicis 



Adeleidae 

 Barrouxia sp. 



Eimeriidae 

 Adelina cryptocerci 



Adeleidae 

 Ovivora thalessemae 



Aggregatidae 

 Klossia loosei 



Adeleidae 

 Adelina deronis 



Adeleidae 



Zygotic 



On being taken into the digestive tract of a host, the sporozoites are 

 released (7) and they penetrate the gut wall (8) into the coelome 

 where they enter coelomic cells. The first generation of merozoites 

 (10 to 12) greatly increases the infection. The schizonts of the second 

 generation of merozoites (13, 14) are already differentiated as to 

 sex, about twice as many smaller merozoites being produced from a 

 male schizont than larger merozoites formed from female schizonts. 

 Young macrogamonts penetrate host cells and are joined by micro- 



FiG. U. Diagrammatic outline of life cycle of AdeVma deronis, 

 from Hauschka (1943). 



1, zygote, chromosomes undergoing synapsis; 2, metaphase, meiotic division of 

 zygote; 3, telophase, first zygotic division; 4, nuclear divisions in zygote, two divid- 

 ing faster than the other two; 5, sporogony, young spores; 6, fully developed spores; 

 7, release of sporozoites in host gut lumen; 8, penetration of gut wall by sporozoites; 

 9, 10, young schizonts; 11, 12, merozoites, first generation; 13, schizonts, second 

 generation; 14, 16, merozoites, second generation; 15, aberrant form of schizogony; 17, 

 young gamonts in host cell; 18, nearly full-grown gamonts; 19, nuclear division in 

 microgamont; 20, one microgamete penetrating macrogamete. 



