PARASITES IN MALARIAL FEVER 25 



the more resistant sexual forms are produced instead of 

 asexual schizonts. Ross gives reasons for believing that 

 they take ten days to form. In the earlier stages they 

 affect the red cells like schizonts and cause them to 





FIG. S.a to e, Phases in the asexual development of the malignant 

 malarial parasite; P.falciparum, x to z, phases in the sexual development 

 x y z, of the female ; x l y ] z l , of the male. 



become adhesive, but by the time the gametocyte is fully 

 developed the red cell is reduced to a mere decolorized 

 shell and is no longer adhesive, and so circulates with the 

 blood throughout the body and in the peripheral cir- 

 culation. If these gametocytes, the potentially sexual 



