PLASMODIUM. 281 



234. Plasmodium cynomolgi Mayer. (Fig. 125 (PI. II).) 



Plasmodium cynomolgi, Mayer, 1908, pp. 314-22, pi. xxi ; Flu, 

 1908, pp. 323-30, pi. xxii ; Blanchard & Langeron, 1913, 

 pp. 529-42, pis. viii-ix ; pp. 599-607, pi. x ; Castellani & Chal- 

 mers, 1919, p. 515. 

 ■fPlasmodium cynomolgi (?), Donovan, 1920, p. 721. 

 Plasmodium cynomolgi, Miihlens, 1921, p. 1612-14, fig. 32 ; Wen- 

 yon, 1926, p. 969. 

 Plasmodium inui, Wenyon, 1926, p. 971 ; Knowles, 1928, p. 439 ; 



Reichenow, 1929, p. 1007, fig. 993. 

 Plasm,odium cynomolgi, Reichenow, 1929, pp. 1007—8, fig. 994. 

 Plasmodium inui (?),' Green, 1931, pp. 649-50 ; 1932, pp. 455-77, 

 7 figs. 

 ■\Plasmodium kochi (?) (part), Napier & Campbell, 1932, pp. 246-9. 

 ^Plasmodium sp. (part), Knowles & Das-Gupta, 1932, pp. 300-20, 



7 pis. & 6 charts ; Sinton & MuUigan, 1932, p. 324. 

 ■fPlasmodium inui var. cynomolgi, Sinton & Mulligan, 1932 a, 



pp. 396-405. 

 '\Plasmodium cynomolgi, Sinton, 1934 a, pp. 48—50 ; 1934 6, 

 pp. 392, 399-400 ; Mulligan, 1935, pp. 288-300, pi. iv, figs. 1-35. 

 Plasmodium cynomolgi, Coatney & Roudabush, 1936, p. 339. 



Young rings, 2-5 ju, in diameter, round, or oval, with promi- 

 nent chromatin dot and well- developed vacuole. Two or 

 three rings sometimes seen in same red corpuscle ; infested 

 corpuscle usually unaltered ; no stippling. Growing forms 

 often show marked amoeboid movement, resembb'ng that seen 

 in P. vivax. Pigment scanty, appears later, and is darker and 

 coarser than in P. inui ; vacuolation, especially in large 

 forms, not marked ; infected red corpuscles appreciably 

 enlarged and pale ; stippling resembling Schiiffner's dots, 

 conspicuous. Schizonts common in peripheral blood ; mature 

 schizonts with eight to sixteen merozoites irregularly scattered ; 

 pigment in small dense clump ; infected red corpuscles with 

 marked pallor and prominent stippling. A minute accessory 

 chromatin dot frequently seen in merozoites and young rings. 

 Schizogony cycle takes forty-eight hours to complete. Game- 

 tocytes intra-corpuscular or free, larger than the normal red 

 corpuscle. Female gametocytes round or oval ; cytoplasm 

 deep blue, chromatin small, compact, and eccentric ; pigment 

 not very abundant, and granules darker and coarser than in 

 P. inui. Male gametocytes smaller, cytoplasm staining 

 less deeply, chromatin central or peripheral, larger and less 

 deeply staining than in the female gametocytes. Sporogony 

 cycle in mosquitoes. 



Remarks. — P. inui was described by Halberstadter and 

 Prowazek (1907) from monkeys {Macaco) from Borneo. 

 Mayer (1908) described P. cynomolgi, which was generally 

 considered as identical with P. inui. He (1908) could obtain 

 no development in Culex pipiens nor in Aedes (Stegomyia) 

 segypti (Linn.) [^ Aedes argenteus] ; he observed small oocysts 

 in Anopheles maculipennis, but could not follow the complete 



