THEILBRIA. 295 



PiROPLASMiDEA Under H^MOSPOBIDIA on grounds of practical 

 convenience, and have divided the order into four famihes 

 (see p. 209). 



The two families, Theileriidae and Babesiidse stand in much 

 the same relationship to one another as Hsemoproteidse to 

 Plasmodiidae. 



Genus THEILERIA Bettencourt, Franca, & Borges, 1907. 



Piroplasma (part), Stephens & Christophers, 1903 b, pp. 335-6; 



Theiler, 1904, pp. 1-20. 

 Theileria, Bettencourt, Franca, & Borges, 1907, pp. 341-9 ; Nuttall, 



Fantham, & Porter, 1909, pp. 325-40 ; Gonder, 1910 a, pp. 143- 



64 ; 1910 b, pp. 49-52 ; 1911 a, pp. 222-31 ; 1911 b, pp. 170-8 ; 



Minchin, 1912, pp. 379-80, 382; Nuttall, 1913, pp. 302-20; 



Hegner & Taliaferro, 1924, p. 305 ; Wenyon, 1926, pp. 992, 1029- 



39 ; Knowles, 1928, pp. 457-9 ; Reichenow, 1929, pp. 1022-7 ; 



Kudo, 1931, p. 289 ; Calkins, 1933, p. 566 ; Reichenow, 1935, 



p. 377. 



With the characters of the family. 



Remarks. — It is not easy to decide whether a particular 

 form met with in the blood is a Theileria or a Babesia. In the 

 former, schizogony takes place in the endothehal cells of the 

 capillaries of the internal organs, and forms produced there 

 enter the red corpuscles and are seen in the peripheral blood. 

 Unhke Babesia, they do not multiply in the red corpuscles. 

 The blood is consequently not infective when inoculated to 

 healthy animals imless endothelial cells containing schizonts 

 happen to be present. 



248. Theileria parva (Theiler). (Fig. 144.) 



Piroplasma bigemina, a stage of, Koch, 1898. 



Piroplasma kochi, Stephens & Christophers, 1903 6, pp. 335-6, 

 fig. 75. 



Piroplasma parvum, Theiler, 1904. 

 ■\Piroplasma parvum, Lingard, 1907, p. 274, pi. vii, fig. 1, 8. 



Theileria parva, Bettencourt, Franca & Borges, 1907, pp. 341-9, 

 pis. xvii, xviii ; Nuttall, Fantham & Porter, 1909, pp. 325-40. 

 '\Piroplasma parvum, Gaiger, 1910, p. 66. 



Theileria parva, Gonder, 1910 a, pp. 143-64 ; 1910 b, pp. 49-52 

 1911 a, pp. 222-31 ; 1911 b, pp. 170-8 ; Minchin, 1912, p. 382 

 Nuttall, 1913, pp. 302-20 ; Castellani& Chahners, 1919, pp. 498-9^ 

 fig. 164 ; Hegner & Taliaferro, 1924, p. 305 ; Saceghem, 

 1925, pp. 651-60; Wenyon, 1926, pp. 1029-34, fig. 428; 

 Sergent, Donatien, Parrot, Lestoquard, & Plantiu-eax, 1926; 

 p. 1362 ; 1927 a, pp. 489-506, 3 figs. ; 1927 b, pp. 721-84 

 23 figs. ; 1927 c, pp. 161-87, 5 figs. ; Knowles, 1928, p. 457 

 figs. 106, 107 ; Reichenow, 1929, pp. 1032-4, figs. 1007-11 

 Kudo, 1931, p. 289, fig. 122, i ; du Toit, 1931, pp. 547-8 

 Reichenow, 1935, p. 377. 



The Cycle in Cattle. — The sporozoites injected by the tick 

 collect in the spleen, lymphatic glands, and other organs, 

 penetrate the endothelial cells of the capillaries, grow rapidly, 



