The Human Malarial Parasites 



507 



tuates in the formation of from fifteen to twenty-five small, rounded 

 or ovoid, pale, unpigmented bodies, the merozoits or spores. * These 

 become freed from the pigment and attached to new red corpuscles, 

 in which they are easily recognized as the "tiny-rings" that begin 

 the schizogonic cycle. The gametocytes of the tertian parasite, the 

 "free spheres," as they are sometimes called, are large, rounded or 

 slightly ovoid bodies, with a uniformly dull bluish-gray or grayish- 

 green protoplasm, in the interior of which there is always a circular 

 or semicircular area peripherally or centrally situated, and colorless. 

 Except in this area the pigment is distributed throughout the parasite. 

 The larger or macrogametocyte, the female parasite, measures 10 

 to 14 ju in diameter. It has a greenish or grayish-green or almost 



'-^^•' 



Fig. 184. — Parasite of tertian malarial fever: a, b, c, d, e, f, g, Growing pig- 

 mented parasite in the red blood-corpuscles; h, spores formed by segmentation 

 of the parasite — no rosette is formed, but concentric rings of the cytoplasm divide; 

 i, macrogametocyte; i, microgametocyte with spermatozoits. 



colorless protoplasm, containing an oval or bean-shaped colorless 

 area almost haK as large as the organism itself. Yellowish-brown 

 pigment in short, broad rods is sparingly scattered throughout the 

 substance elsewhere. 



The microgametocyte or male form is approximately the size 

 of a red blood-corpuscle— 8 to 9 /^ in diameter. It stains more deeply 

 than its mate and contains more and coarser pigment granules. 



in. Plasmodium Falciparum (Welch, f 1897).— This is the 



Synonyms—Oscillana, malarias pro parte, Laveran, 1881. Hasmamoeba 

 gaecox, Grassi et Feletti, 1890. Laverania malarias, Grassi et Feletti, 1890. 

 Haemamoeba malariae praecox, Grassi et Feletti, 1892. Hsemomenas praecox, 

 Ross, 1899. Plasmodium malarias praecox, Labb6, 1899. Plasmodium prse- 



Bass asserts that Plasmodium vivax produces 32 merozoits. 

 [Article "Malaria" in "A System of Practical Medicine by American 

 Authors," 1897, p. 138. 



