HAEMOSPORIDIA 



499 



cell nucleus not displaced; chicks are susceptible, but canaries re- 

 fractory. Experimentally it developed up to the oo cyst-stage in 

 Anopheles quadrimaculatus, though the sporozoites did not develop 

 (Coggeshall, 1941). 



Family 2 Haemoproteidae Doflein 



Schizogony occurs in the endothelial cells of vertebrates; mero- 

 zoites penetrate into circulating blood cells and develop into game- 

 tocytes; if blood is taken up by specific blood-sucking insects, 

 gametocytes develop into gametes which unite to form zygotes that 

 undergo changes similar to those stated above for the family Plas- 

 modiidae. 



Fig. 233. The life-cycle of Haemoproteus columhae. (Several authors), 

 a, a sporozoite entering an endothelial cell of the pigeon; b, growth of a 

 schizont; c, segmentation of multinucleate schizont into uninucleate 

 cytomeres; d-i, development of cytomeres to produce merozoites; j-m, 

 development of microgametes; n-p, development of macrogamete; q, 

 fertilization; r, s, ookinetes; t, a young oocyst in the stomach wall of 

 a fly; u, a ruptured mature oocyst with sporozoites. a-k, n, o, in the 

 pigeon, I, m, p-u, in Pseudolynchia maura. 



