610 Malaria 



rings, measuring from one-fourth to one-third the diameter of the 

 corpuscle, are similar to those of P. vivax. Although the cytoplasm and 

 chromatin are slightly coarser and the cytoplasm may stain a little more 

 intensely than in P. vivax, it is difficult or impossible to distinguish the 

 two at this stage. After a few hours of growth, the vacuole disappears and 

 the cytoplasm becomes compact. P. malariae rarely shows pseudopodia. 



Fig. 13. 5. Plasmodium ovale: A. Normal red corpuscle. B, C. Young 

 parasites. D, E. Stages in growth; stippling of corpuscles indicated. F-I. Bi- 

 nucleate and multinucleate schizonts. J. Merozoites. K. Micrngametocyte. 

 L. Macrogametocyte. Semidiagrammatic. 



Pigment is deposited early and is appreciably more abundant than in 

 the other parasites of man. Even half-grown parasites may show as many 

 as 30-50 dark or almost jet-black granules. Older growth stages may form 

 bands, stretching more or less completely across the corpuscle. Such bands 

 are usually considered a diagnostic feature because they are so much more 

 common in P. malariae than in the other species. In addition to the 

 bands, growth stages are often seen as compact masses without pseudo- 

 podia. The mature schizont approximates the diameter of the corpuscle. 



