SPOROZOA, GREGARINIDA 381 



The repeated nuclear division is followed by formation of large 

 numbers of gametes (d-f) which unite in pairs (g). The zygotes 

 thus formed develop into spores, each possessing 8 sporozoites 

 (h). Meanwhile the host pupa emerges as an adult mosquito, and 

 the spores which become set free in the lumen of the tubules, pass 

 into the intestine, from which they are discharged into water. 

 Larvae swallow the spores and acquire infection. 

 Eugregarinina are divided into 2 tribes: 



Trophozoite not septate Tribe 1 Acephalina 



Trophozoite septate Tribe 2 Cephalina (p. 391) 



Tribe 1 Acephalina KoUiker 



The acephalines are mainly found in the body cavity and 

 organs associated with it. The infection begins by the ingestion of 

 mature spores by a host, in the digestive tract of which the sporo- 

 zoites are set free and undergo development or make their way 

 through the gut wall and reach the coelom or various organs such 

 as seminal vesicles. Young trophozoites are intracellular, while 

 more mature forms are either intracellular or extracellular. 



Spores with similar extremities 

 Spores biconical 

 Sporadins solitary 



Anterior end not differentiated .- . . 



Family 1 Monocystidae (p. 382) 



Anterior end with a conical or cylindro-conical trunk 



Family 2 Rhjmchocystidae (p. 384) 



Sporadins in syzygy 



Spores with thickenings at ends 



Family 3 Zygocystidae (p. 384) 



Spores without thickenings 



Family 4 Aikinetocystidae (p. 385) 



Spores not biconical 



Spores navicular Family 5 Stomatophoridae (p. 386) 



Spores round or oval 



No encystment Family 6 Schaudinnellidae (p. 387) 



2 sporadins encyst together. . .Family 7 Diplocystidae (p. 387) 

 Spores with dissimilar ends 



Spores with epispore Family 8 Urosporidae (p. 389) 



Spores without epispore Family 9 Allantocystidae (p. 391) 



Spores unobserved; grown trophozoites with cup-like depression at 



posterior end to effect syzygy 



Family 10 Ganymedidae (p. 391) 



