SEXUAL PHENOMENA IN THE PROTOZOA 



231 



gametes and microgametes occurs during the same day, and after a 

 similar period of asexual increase, showing that the same ultimate 

 causes probably operate in each. The macrogamete is distinguished 

 from the schizonts by the possession of a reserve store of nutriment, 



Fig. 128. Life-history of a Coccidium. [SCHAUDINN.] 



a. b, c, schizonts and asexual reproduction (schizogony). The merozoites at c repeat the cycle 

 or pass on to the following stages: d, e,f, development of the female or macrogamete; A, i,j, 

 development of the male gametes; g, copulation; k and /, stages in the formation of the spores 

 and sporozoites. 



in the form of granules, which are used in the later development 

 The storage of these granules begins in the young merozoite (Fig. 

 128, e-g] and in the close vicinity of the nucleus. 1 The nucleus is 

 not essentially different from that of the schizont, but at one stage, 

 according to Schaoidinn, a large amount of chromatin is thrown out of 



1 Cf. yolk-formation in eggs of Metazoa ; see Wilson, The Cell, p. 155. 



