COCCIDIA 431 



Genus Chagasella Machado. Oocyst with 3 spores, each with 4 

 or 6 (or more) sporozoites; in hemipteroiis insects. 



C. hartmanni (Chagas). In gut of Dysdercus ruficolUs; oocysts 

 with 3 spores about 45At in diameter; spore with 4 sporozoites, 

 about 35/i by 15m. 



Family 2 Haemogregarinidae Leger 



With 2 hosts: vertebrates (circulatory system) and inverte- 

 brates (digestive system). 



Genus Haemogregarina Danilewsky. Schizogony takes place 

 in blood cells of vertebrates; merozoites develop into gameto- 

 cytes; when taken into gut of leech or other blood-sucking in- 

 vertebrates, sexual reproduction takes place; microgametocyte 

 develops 2 or 4 microgametes; sporozoites formed without pro- 

 duction of spores. 



H. stepanowi D. (Fig. 196). Schizogony in Ernys orbicularis and 

 sexual reproduction in Placohdella catenigera; sporozoites intro- 

 duced into blood of the chelonian host by leech (a), and enter 

 erythrocytes in which they grow (d-g) ; schizogony in bone-mar- 

 row, each schizont producing 12-24 merozoites (A); schizogony re- 

 peated (i); some merozoites produce only 6 merozoites (j, k) 

 which become gametocytes (l-o); gametogony occurs in leech; 4 

 microgametes formed from each microgametocyte and become 

 associated with macrogametocytes in gut of leech (p-r); zygote 

 (s) divides three times, and develops into 8 sporozoites {t-w). 



Haemogregarina are commonly found in various frogs (Fig. 

 195, g, h) and in fishes (Fig. 195, i-m). 



Genus Hepatozoon Miller. Schizogony in cells of liver, spleen, 

 and other organs of vertebrates; merozoites enter erythrocytes or 

 leucocytes and develop into gametocytes; in blood-sucking 

 arthropods (ticks, mites), micro- and macrogametes develop and 

 unite in pairs ; zygotes become oocysts which increase in size and 

 produce sporoblasts, spores, and sporozoites. 



H. muris (Balfour) (Fig. 195, n). In various species of rat; sev- 

 eral specific names were proposed on the basis of difference in 

 host, locality, and effect on the host, but they are so indistinctly 

 defined that specific separation appears to be impossible. Schi- 

 zogony in liver of rat; young gametocytes invade mononuclear 

 leucocytes and appear as haemogregarines ; when blood is taken 

 in by the mite, Laelaps echidninus, union of 2 gametes produces 



