SPOROZOA 



IOI 



merozoites, and round off in the gut. The microgametocyte, or 

 spermatogone, has the same character, but is smaller ; it applies 

 itself like a cap to one pole of the oogamete, which has 

 rounded off; it then divides into four sperms, whose cytoplasm 



FiG. 34. Life-history of Coccidium schubergi. a, Penetration of epithelium-cell of host 

 by sporozoite ; b-d, stages of multiple cell- formation in naked state (schizogony) ; e,f, 

 formation of oogamete ; g, conjugation ; h-j, formation of sperms (s) ; k, development 

 of zygote (fertilised ovum) to form four spores ; I, formation of two zoospores (or 

 sickle germs) in each spore. (From Calkins's Protozoa, after Schaudinn. ) 



is not sharply separated; one of these then separates from the 

 common mass, enters the oogamete, and so conjugation is effected, 

 with an oosperm as its result. This latter mode of conjugation 

 is that of Adelea ovata and Coccidium lacazei : the former is 

 probably the more primitive and the commoner. The sperms 



