92 



THE INVERTEBRATA 



Fig. 75. A diagram of the life cycle of Plasniodimn vivax. After Borradaile. 

 1-7, Schizogony (Merogony), asexual reproduction which takes place in 

 man. 8—13, Gamogony and syngamy, which take place in the stomach of a 

 mosquito. 14-20, Sporogony by the zygote (sporont), which takes place in 

 the body cavity of the mosquito, i, Infection of a red corpuscle. 2, Signet- 

 ring stage. 3, Amoeboid stage. 4, Full-grown schizont preparing to divide. 

 5, Multinucleate stage. 6, Rosette stage, corpuscle breaking up. 7, Free 

 schizozoites. 8, Infection of red corpuscles by young gamonts. 9, Full- 

 grown gamonts free in the mosquito's stomach. 10, 11, Formation of gametes. 

 12, Conjugation. 13, Zygote in the ookinete condition. 14, Invasion by zy- 

 gote of endoderm cell of mosquito. 15, Encystment. 16, Sporoblasts formed 

 by division of zygote (sporont). 17, 18, Formation of sporozoites. 19, In- 

 vasion by latter of salivary gland. 20, Sporozoites injected into blood of a man. 



