SPOROZOA 



443 



guished, but very early in its growth it becomes actively ameboid 

 and extends irregular and slender processes into the protoplasm 

 of its host cell. As the parasite enlarges, the erythrocyte, often 

 but not always, becomes swollen, paler, and shows a coarse granu- 



FlG. 206.- — Plasmodiufn vivax. Stages of growth in the asexual cycle, commonly 

 seen in the peripheral blood. Three of the cells show granules in the hemoglobin, 

 the stippling of Schilffner. X2200. (^After Doflein.) 



lation, the stippling of Schueffner. The parasite often attains 

 a diameter greater than that -of the average blood cell before it 

 segments. The segmentation gives rise to from 15 to 30 mero- 

 zoits which enter new erythrocytes and begin the cycle anew. 



Fig. 207. — Plasmodium vivax. Multinucleated 

 stage preceding division and the stage of multiple 

 division (sporulation) ; found in the blood just be- 

 fore and during a chill. X2200. (AfUr Doflein.) 



Fig. 208. — Plasmodium 

 vivax. Double infection of 

 a red blood cell which is 

 considerably enlarged as a 

 result ; SchiifEner's stippling 

 slight. X2200. {After 

 Doflein.) 



This complete cycle of schizogony takes place in the peripheral 

 cfrculation and requires almost exactly 48 hours. 



The young parasites destined to become gametocytes ex- 

 hibit relatively less ameboid movement. Their pigment exists as 

 large granules, some of them even rod-shaped. The macrogame- 

 tocyte attains a diametef of 15 to 25/4 and usually destroys its 



