606 Malaria 



Fig. 13. 2. Plasmodium vivax, semidiagrammatic: A. Uninvaded red cor- 

 puscle, in outline. B. Young ring. C. Marginal form. D. Older ring stage; 

 Schiiffner's dots indicated in cytoplasm of the corpuscle. E-G. Growth stages. 

 H-K. Binucleate, tetranucleate and multinucleate schizonts. L. Formation 

 of merozoites. M. Microgametocyte. N. Macrogametocyte. 



preparations. With continued growth of the parasite, the corpuscle is 

 gradually enlarged to about 2-4 times the normal size and may be dis- 

 torted. Invaded corpuscles are usually decolorized and may show small 

 eosinophilic granules, Schiiffner's dots, possibly derived from the granules 

 of reticulocytes. The percentage of corpuscles showing Schiiffner's dots 

 may vary from patient to patient — for example, from 13.2 to 36.4 per 

 cent in specific cases (51). By the end of 36 hours, growth has practically 

 ceased and nuclear division is under way. At this point, the schizont 

 almost fills the enlarged corpuscle. After about 46 hours or less, depend- 



