HAEMOSPORIDIA 505 



Babesia occur also in sheep, goats, pigs and horses. 



B. canis (Piana and Galli-Valerio), Pyriform bodies 4.5-5m long; 

 the organism causes malignant jaundice in dogs; widely distributed; 

 transmitted by the ticks: Hacmaphysalis leachi, Rhipicephalus san- 

 guineus, and Dermacentor reticulatus. 



Genus Theileria Bettencourt, Franga and Borges. Schizogony 

 takes place in endothelial cells of capillaries of viscera of mammals; 

 certain forms thus produced enter erythrocytes and appear in 

 the peripheral circulation. 



T. parva (Theiler) (Fig. 236, i-l). In the cattle in Africa, cause of 

 African coast fever; intracorpuscular forms 1-2/x in diameter; trans- 

 mitted by the tick, Rhipicephalus evertsi. 



^ %^ ^ ^ 



Fig. 237. Toxoplasma gondii. X about 1750. (Chatton and Blanc) 

 a, isolated organisms; b, 2 trophozoites; c, organisms undergoing binary 

 fission; d, a host cell with many organisms which developed by repeated 

 binary fission. 



Genus Dactylosoma Labbe. In blood of reptiles and amphibians; 

 schizogony and gametocytes in erythrocytes; invertebrate hosts 

 unknown. 



D. ranarum (Kruse) (Fig. 236, m-s). In European frogs; schizonts 

 4-9m in diameter; 4-16 merozoites, 2-3m by 1-1. 5m; gametocytes 

 5-8Mby 1.5-3/i. 



Genus Toxoplasma NicoUe and Manceaux. Minute intracellular 

 parasites in leucocytes and endothelial cells of various mammals, 

 birds and reptiles; round or ovoid; ordinarily not common in periph- 

 eral blood; often abundant in the liver, spleen, bone marrow, lung, 

 brain, etc.; reproduction by binary fission. The genus has been often 

 mentioned in connection with exo erythrocytic schizogony of Plas- 

 modium. Many "species" have been designated by various observers 

 on the basis of the difference in host species. 



T. gondii N. and M. (Fig. 237). In Ctenodaclylus gundi, a rodent 

 in North Africa; a variety of experimental animals susceptible to it; 

 crescentic; 4-6m by 2-3m; division occurs intra- or extra-cellularly. 



