PLASMODIUM. 273 



The Cycle in the Mosquito. — ^The development in the mos- 

 quito is on the same Hnes as in Laverania malarise. As the 

 gametocytes of P. vivax are the largest, the zygotes and 

 oocysts of this species are also probably larger than in the 

 other species. The pigment produced in this species is of 

 a hght brown colour, while that in the other two species of 

 human malarial parasites is dark brown or black : thus 

 zygotes and oocysts with light brown pigment will be those 

 of P. vivax. 



Remarks. — Grassi (1900) and Schaudinn (1902 a) described 

 certain changes in the female gametocyte which they inter- 

 preted as parthenogenesis. J. D. Thomson (1917) and Wenyon 

 (1926) have refuted the theory and explained that the appear- 

 ances observed may be due to a red corpuscle being infected 

 with two or more parasites, which may both be schizonts, 

 or a schizont and a gametocyte, and thus combinations of all 

 sorts of appearances may result. 



Chalmers and Archibald (1920) described what they call 

 the " tenue " phase of P. vivax, having the same relation to 

 this species as P. tenue Stephens has to Laverania malarias. 



James, Nicol, and Shute (1933) gave a description of the 

 life-cycle of Plasmodium ovale Stephens, with different 

 characters to separate the species from the other malarial 

 parasites. According to them the parasite is identical with 

 that described by Craig in 1900 and 1914, but is distinct from 

 P. camarense Emin. Giovannola (1935) beheves that P. ovale 

 is a modification of P. vivax after a long residence in the 

 human host, and cites historical, cHnical, and morphological 

 evidence to support his claim. 



Habitat. — Blood of man in almost all parts of India {vide 

 map on p. 279), and in the body of several species of Anopheles, 

 such as A. annularis Van der Wulp, A. culicifacies Giles, 

 A. fluviatilis James (=.4. listoni Liston), A. maculatus Theo., 

 A. minimus Theo., ^. philippinensis Ludl., A. stephensi Liston, 

 A. sundaicus Rodenwaldt, and A. varuna Iyengar. 



233. Plasmodium malariae (Laveran). (Fig. 124 (PL I).) 



Malarial parasites, Laveran, 1880 a, p. 158 ; 1881, pp. 627-30 ; 



1882, p. 737. 

 Oscillaria malar iee (part), Laveran, 1883, p. 113. 

 Plasmodium var. quartana, Goigi, 1885 ; 1886 ; 1890. 

 Amoeba malarise febris quartanee, Celli, 1891. 

 Plasmodium, malarise quartanee, Celli & San Felice, 1891. 

 Hcemam,ceba febris qu^artanse, Marchiafava & Bignami, 1891. 

 Hsemammba malarise, Grassi & Feletti, 1892, p. 10. 

 Hsemamceba laverani var. quartanarum, Labbe, 1894, p. 170. 

 ^Hssmam^cBba malarise, Ross, 1898, pp. 133—6. 

 Plasmodium malarise quartanum, Labbe, 1899, p. 82, fig. 147 b. 

 Plasmodium malarise, Liihe, 1900, p. 460 ; Neveu-Lemaire, 1900, 

 p. 8, pi. i, fig. 1. 

 SPOR. T 



