622 PROTOZOOLOGY 



lings is said to be highly fatal and appears often suddenly. In addi- 

 tion to the Simulium mentioned above, Simulium parnassum appears 

 to be a vector (Fallis, Davies and Vickers, 1951). 



Mathis and Leger: Macrogametocytes, oval; 14-15/x by 4.5-5.5/*; 

 several vacuoles in darkly stained cytoplasm. Microgametocytes, 

 oval; slightly smaller; cytoplasm stains less deeply. Infected host 

 cells about 48/* long; nucleus elongate. 



Huff found that (1) young schizonts are in macrophages of, and 

 also extracellularly in, the spleen and liver; (2) two types of schi- 

 zonts occur: one, "hepatic schizonts" in hepatic cells which cause 

 no distortion or alteration of the host cell, and the other, "megalo- 

 schizonts" in the blood vessels of, or extra vascularly in, the heart, 

 spleen, liver and intestine; (3) megaloschizonts become divided into 

 many cytomeres which give rise to numerous merozoites; (4) young 

 gametocytes occur in lymphocytes, monocytes, myelocytes and late 

 polychromatophile ery throblasts ; (5) the cells in which fully grown 

 gametocytes occur, appear to be macrophages. Life history and effect 

 on the blood of host birds (Fallis, Davies and Vickers, 1951); de- 

 velopment in ducklings (Chernin, 1952). 



Other reported species: L. smithi Laveran and Lucet (1905) in 

 turkey; L. bonasae Clarke (1935) in ruffed grouse; L. andrewsi 

 Atchley (1951) in chicken, etc. 



Family 3 Babesiidae Poche 



Minute non-pigmented parasites of the erythrocytes of various 

 mammals; transmission by ticks. 



Genus Babesia Starcovici (Piroplasma Patton). In erythrocytes of 

 cattle; pear-shaped, arranged in couples; sexual reproduction in fe- 

 male ticks in which developing ova, hence young ticks, become in- 

 fected with ookinetes, producing sporozoites which enter salivary 

 glands (Dennis). Taxonomy (Toit, 1918). 



B. bigemina (Smith and Kilborne) (Figs. 268; 269, a-d). The 

 causative organism of the haemoglobinuric fever, Texas fever or 

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

 thropod plays an important role in the transmission of a protozoan 

 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 knowledge of the develop- 

 ment of the organism. 



Sexual reproduction followed by sporozoite formation occurs in 

 the tick, Boophilus (Margaropus) annulatus; when a tick takes in 



