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HANDBOOK OF PROTOZOOLOGY 



Each trophozoite increases in size, and finally two encyst to- 

 gether. These are gametocytes. Within the cyst membrane, 

 the nucleus in each gametocyte undergoes repeated division, 

 forming a large number of small nuclei which by a process of 

 budding transform themselves into numerous gametes. The 

 gametes may be isogamous or anisogamous. Each of the 

 gametes produced in one gametocyte unites with one formed 

 within the other, so that a large number of zygotes are produced. 

 Each zygote becomes surrounded by a resistant membrane 

 and its contents develop into the sporozoites which are usually 



Fig. 123 The development of Lankesteria culicis. 

 X about 500. (After Wenyon). 



a. Entrance of sporozoites into the epithelial 

 cell and growth stages of trophozoites. 



b. Trophozoite free in the host gut lumen. 



c. Association of grown trophozoites in pair, 

 d-f. Stages in gamete-formation. 



g. Gametogony. 



h. Development of spores from zygotes. 



i. A spore. 



j. Germination of spore in the host gut. 



eight in number. These spores germinate when taken into the 

 alimentary canal of a host animal and the liberated sporozoites 

 undergo changes outlined above. 



