534 Malaria 



The gametocytes of the parasite remain for some time in 

 the red corpuscles without division, but, finally, become free 

 spherical bodies. Two sizes can be made out, one a little 

 larger, the macrogametocyte or female, the other, the 

 microgametocyte or male. Bach has protoplasm, with a tend- 

 ency to take a blue-gray color and appear uniformly granu- 

 lar, except that at some part of the periphery of each there is 

 a circular or semicircular area that is free from granules. 

 This area is larger in the microgametocyte. 



Fig. 174- Fig- J 75- 



Figs. 174, 175. Gametocytes of plasmodium malariae: 85, The macro- 

 gametocyte; 86, the microgametocyte (Kolle and Wassermann). 



II. Plasmodium Vivax (Grassland Feletti,* 1890). This 

 is the most common of the malarial parasites of man, and 

 occasions the " benign " tertian fever. It is a large parasite, 

 the full-grown schizont (meroblast) , ready to form merozoits, 

 and the gametocytes all exceeding the size of the red blood- 

 corpuscles. It matures in forty-eight hours, but not with 

 mathematic precision. In single infections the greater 

 number of the parasites are of the same age and present the 

 same appearance, but various shapes and ages may be found 

 together. In double infections, with paroxysms every day, 

 parasites of different ages may be found. 



The youngest form in which the parasite can be observed 

 is that of a tiny ring in a red blood-corpuscle. The periphery 

 of this ring (when the blood is stained with polychrome 

 methylene-blue) is outlined with blue, at one side there is 



* " Centralbl. f. Bakt. u. Parasitenk.," 1890, vn, 396; 1891, x, 449, 

 481, 517. 



