INVERTEBRATA. 



H III IV 



425 



Vlllb 



JVJS- -- Vila 



XVIII 



XVII 



XII! 



XIV 



Fia,207. DIAGRAM ILLUSTRATING THE LIFE-HISTORY OF THE MALARIAL PARASITE. 

 I.-V. 6, successive stages in the growth of the trophozoite within a red corpuscle. 

 7-9, division of trophozoite into merozoites. VI., trophozoite in crescent form, 

 becoming a gametocyte. VII. a, VII.fi, male and female crescents. VIII. a, VIII.6, 

 male and female ovals. IX. a, IX.S, male and female gametocytes ; IX.a, the male 

 with divided nucleus. X.a, formation of male gametes; X.6, female gamete 

 which has ejected a particle of chromatin. XI. and XII., conjugation. XIII., 

 the motile zygote which penetrates the epithelium of the mosquito's stomach. 

 XIV. -XVIII. , development of the sporozoites. Stages above the dotted line occur 

 in the human host, those below in the mosquito. (After Minchin, Ark Sporozoa in 

 Lankester'o Treatise on Zoology.) 



