FERTILIZATION BY EXOGAMY 



151 



of maturity manifesting themselves in other ways than by size changes. 

 In other cases the conjugating cells are reduced in size, but without 

 differences of a sexual character, and in still other cases there is a 



Fig. 64 



Ameba diploidea, Hartmann and Niigler. A and B, ordinary individuals at early and 

 mid-pliases of division; C, D, E, union of two indi\'iduals within cyst, and fusion of the 

 double nuclei in each cell; F, ameba after fusicjn of cell bodies, now with two nuclei, creep- 

 ing out of cyst. 



