420 



SPECIFIC MICRO-ORGANISMS 



in general has been most thoroughly studied by Grassi. 1 PL falcip- 

 arum is the parasite of estivo-autumnal or pernicious malaria of 



FIG. 191. Plasmodium falciparium, forms in the asexual cycle (schizogony). 

 A, Multiple infection of an erythrocyte, showing signet rings and parasites attached 

 to the external surface. B and C, Growing parasites with Mauer's granules in the 

 erythrocytes. D, Growing parasite without granulation of the hemoglobin. E, Half- 

 grown parasite showing pigment. F, and G, Multiple division (sporulation), rarely 

 seen in the peripheral blood. (After Doflein.} 



man. The young organism is i to 1.5/4 in diameter. It pene- 

 trates a red blood cell and enlarges. A vacuole appears in the 



center, giving the parasite the 

 appearance of a signet ring, the 

 setting being represented by 

 the nucleus or chromatin gran- 

 ule which stains violet red with 

 the Romanowsky stains. The 

 parasite attains a diameter of 

 about 6/j, when it segments to 

 produce 7 to 16 merozoits or 

 agametes which enter new ery- 



FIG. 192. Section through a capil- 

 lary in the brain, showing numerous di- 

 viding forms of the non-pigmented type 

 of PL falciparum. (Stained prepara- 

 tion.) From Doflein after Mannaberg.) 



throcytes and repeat the cycle. 

 The larger stages of this cycle of schizogony are rarely seen 

 in the peripheral circulation, and the segmentation of the 



1 Grassi: Die Malaria, lite Auflage, Jena, 1901. 



