PLASMODIUM. 



293 



246. Plasmodium ratulse Donovan. 



■^Plasmodium ratufse, Donovan, 1920, pp. 719-20. 

 Plasmodium ratufce, Wenyon, 1926, p. 974 ; Knowles, 1928, p. 442 ; 

 Reichenow, 1929, p. 1009. 



Very similar to P. vivax of man. Gametocytes predominated, 

 and in a few films the female gametocytes exceeded in number 

 the male forms. 



Remarks. — The species is similar to, if not identical with, 

 P. vassali (Laveran, 1905), the parasite first found by Vassal 

 in Sciurus grisemanus in Annam. 



Habitat. — Blood of the giant squirrel, Ratufa indica 

 Erxleben : Bombay, Malabar. 



247. Plasmodium tyrio de Mello, Fernandes, Correa, & Lobo. 



(Fig. 143.) 



"fPlasmodium tyrio, de Mello, Fernandes, Correa, & Lobo, 1928, 



pp. 513-16, figs. 1-28. 

 Plasmodium tyrio, Coatney & Roudabush, 1936, p. 340. 



Young trophozoites usually circular or oval, very regular ; 

 aberrant or fusiform forms very rare. Ring-forms show a 



G 



H 



Fig. 143. — Plasmodium tyrio de MeUo, Fernandes, Correa, & Lobo. 

 A, B, ring-forms ; C, D, rosette-forms ; E, F, male gameto- 

 cytes ; 6, H, female gametes. (After de Mello, Fernandes, 

 Correa, and Lobo.) 



precocious division of the nucleus into two or three granular 

 masses united together. Schizonts irregular in form, resemble 

 those of P. vivax, and even when fully developed do not 

 cover the entire area of the corpuscle. Large black pigment 

 granules appear irregularly in the cytoplasm of the parasite. 

 Schizogony takes place in the peripheral blood. The number 

 of merozoites varies from four to eight. Gametocytes spherical 

 or ovoid. Male gametocytes almost devoid of pigment ; 

 when the pigment is present, it is in the form of fine dark 

 granules dispersed round the nucleus. Female gametocytes 



