STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 5 1 





Fig. 43. — Life history of malaria parasite, Plasmodium prcecox. i. Sporozoite, 

 introduced by mosquito into human blood; the sporozoite becomes a schizont. 2. 

 Young schizont, ^hich enters a red blood corpuscle. 3. Young schizont in a red 

 blood corpuscle. 4. Full-grown schizont, containing numerous granules of melanin. 

 5. Nuclear division preparatory to sporulation. 6. Spores, or merozoites, derived 

 from a single mother-cell. 7. Young macrogamete (female), derived from a mero- 

 zoite and situated in a red blood corpuscle. 7a. Young microgametocyte (male) 

 derived from a merozoite. 8. Full-grown macrogamete. 80. Full-grown micro- 

 gametocyte. In stages 8 and 8a the parasite is taken into the stomach of a mos- 

 quito; or else remains in the human blood. 9. Mature macrogamete, capable of 

 fertilization; the round black extruded object may probably be termed a "polar 



