442 PROTOZOOLOGY 



by 4. 5-5. 5m, often vacuolated, nucleus with a distinct endosome; 

 microgametocyte slightly smaller; in teal duck (Querquedula crec- 

 ca), China. Herman (1938) observed a species of Leucocytozoon 

 in common black duck (Anas rubripes tristis), red-breasted mer- 

 ganser (Mergus serrator) and blue-winged teal (Querquedula dis- 

 cors) and hold that L. simondi and L. anatis are one and the same 

 species and therefore the latter name is synonymous with the 

 former. 



Family 3 Babesiidae Poche 



Minute non-pigmented parasites of erythrocytes of various 

 mammals; transmission by ticks. 



Genus Babesia Starcovici. In erythrocytes of cattle; pear- 

 shaped, arranged in couples; sexual reproduction in female ticks 

 in which developing ova, hence young ticks, become infected with 

 ookinetes, producing sporozoites which enter salivary glands 

 (Dennis). 



B. Ugemina (Smith et Kilbourne) (Figs. 202; 203, a-d). The 

 causative organism of the haemoglobinuric fever, Texas fever or 

 red-water fever of cattle; the very first demonstration that an 

 arthropod plays an important role in the transmission of a pro- 

 tozoan parasite; the infected cattle contain in their erythrocytes 

 oval or pyriform bodies with a compact nucleus and vacuolated 

 cytoplasm; the division is peculiar in that it appears as a budding 

 process at the beginning. We owe Dennis (1932) for our knowl- 

 edge of development of the organism. 



Sexual reproduction followed by sporozoite formation occurs in 

 the tick, Margaropus annulatus ; when infected tick takes in in- 

 fected blood into gut lumen, isogametes, 5.5-6/x long, are pro- 

 duced; isogamy results in motile club-shaped ookinetes, 7-12/x 

 long, which pass through gut wall and invade larger ova (1-2, in 

 one case about 50, ookinetes per egg) ; each ookinete rounds itself 

 up into a sporont, 7.5-12/^ in diameter, which grows in size and 

 whose nucleus divides repeatedly; thus are produced multinu- 

 cleated (4-32 nuclei) amoeboid sporokinetes, up to 15yu long, 

 which now migrate throughout embryonic tissue cells of tick, 

 many of which cells develop into salivary gland cells; sporoki- 

 netes develop into sporozoites before or after hatching of host 

 tick ; sporozoites bring about an infection to cattle when they are 

 inoculated by tick at the time of feeding. Texas fever once caused 



