424 



SPECIFIC MICRO-ORGANISMS 



parum, and greater success with PL malaria. Details of this work 

 have not yet been published. 



Plasmodium Vivax. The parasite of tertian malaria is dis- 

 tinctly different from the estivo-autumnal parasite. The young 



FIG. 198. Plasmodium 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 Schiiffner. X22oo. (After Do flein.} 



merozoit is i to 2/4 in diameter and practically not to be distin- 

 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- 

 A B 



FIG. 199. Plasmodium vivax. Multinu- 

 cleated stage preceding division and the stage 

 of. multiple division (sporulation) ; found in the 

 blood just before and during a chill. X22oo. 

 (After Do flein.} 



FIG. 200. Plasmodium 

 vivax. Double infection of 

 a red blood cell which is 

 considerably enlarged as a 

 result; Schuffner's stippling 

 slight. X22CO. (After 

 Do flein.} 



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. 

 This complete cycle of schizogony takes place in the peripheral 

 circulation and requires almost exactly 48 hours. 



