THEILEEIA. 299 



referred to Babesia. Brumpt (1923) showed that usually the 

 infections are mild and the schizonts are not apparent, but in 

 intense infections they occiu" in large numbers in the internal 

 organs as well as in peripheral blood. This was confirmed 

 by Velu (1923), Doyle (1924), and Edwards (1925). Ed. 

 Sergent and his co-workers (1924) disagreed -vsdth Brumpt, 

 and stated that T. mutans never produces schizonts, but later 

 (1928) found a few of them. T. mutans and T. parva cannot be 

 differentiated morphologically, and Brumpt (1924) dijfferentiates 

 them biologically as follows : — 



Non-pathogenic, transmissible by direct blood inoculation; 

 persistence of parasites in the blood for long periods 

 (no immunity) T. mutans. 



Highly pathogenic, not transmissible by direct blood inocu- 

 lation ; no persistence of parasites after recovery (com- 

 plete immunity) T. parva. 



Du Toit (1931) recommends the provisional recognition of 

 four species of Theileria in cattle, viz., T. parva, T. dispar, 

 T. annulata, and T. mutans, and these show a gradual transition 

 from the most virulent T. parva to the avirulent T. mutans. 



Cooper (1926 a) remarked that T. mutans was almost 

 universally present in Indian cattle, and showed the occurrence 

 of Koch's " blue bodies " in this species. Datta (1938) has 

 found that the parasite multiples in the lymphoid tissue 

 generally, including that of glands, spleen, etc. 



Habitat. — ^Blood of bulls, Bos indicus Linn. (?), used for 

 Rinderpest hyper-immunisation : Punjab ; United Pro- 

 vinces, Muktesar ; Mysore, Bangalore. 



250. Theileria sp. 



fTheileria sp., " types A & B," Sen & Srinivasan, 1937, pp. 15-37, 

 pi. vii. 



Usually round or shghtly oval forms, having the appearance 

 of signet-rings, and uniformly 1-2 /x in diameter. Stained 

 with Giemsa's or Leishman's stain, the cytoplasm takes a pale 

 blue colour ; the chromatin stains well, two chromatin spots 

 being sometimes connected together. Koch's " blue bodies " 

 present. 



RemarJcs. — Sen and Srinivasan (1937) studied Theileriasis 

 of cattle in a large number of Indian hill bulls artificially 

 infected with a strain isolated from a fatal case at Muktesar. 

 They came to the conclusion that in the present state of our 

 knowledge it is impossible to rely on any morphological 

 features as an indication of the extent of the pathogenicity 

 of the organism. According to them, the diagnosis of the 

 species of Theileria would appear to depend on the quantitative 



