-en. 



H. 



Fig. 39- 



Figures illustrating the stages of the life cycle of the malarial parasite found 

 in Anopheles. A, crescent-shaped gametocytes of Plasmodium i>n- 

 maculatum of pernicious tropical malaria ; Q the microgametocyte ; 

 $ the macrogametocyte. B, further stages in the development of 

 the microgametocyte and the macrogametocyte of Plasmodium 

 vivax ', the nucleus of the macrogametocyte has divided unequally to 

 form a polar body, pb. C, the nucleus of the microgametocyte has 

 broken up into eight karyosomes, ky, each surrounded by a ring of 

 chromatin granules ; the polar body has separated from the macro- 

 gametocyte. D, formation of microgametes from the microgametocyte. 

 E, a single microgamete ; ky, the central karyosome. F, fertilisation 

 of the macrogamete by the microgamete ; J.Q , male pronucleus ; n *j? , 

 female pronucleus. G, the motile zygote or ookinete ; en, fertilisation 

 nucleus, ff, the ookinete (oocyst) surrounded by a very delicate cyst 

 wall, at rest in the tissues of the wall of the stomach of the mosquito ; 

 n, nucleus ; /, pigment. /, multiplication of nuclei in the oocyst. K, 

 the protoplasm of the oocyst has divided into numerous sporoblasts, 

 sp. l>l, each containing a nucleus. Z., early formation of sporozoites 

 from the sporoblasts. M, a ripe oocyst full of minute sporozoites, spz, 

 which are escaping by the bursting of the cyst ; rp, residual protoplasm 

 containing an abortive nucleus (B-G after Schaudinn, the remaining 

 figures after Grassi. The figures are not all drawn to the same scale.) 



