596 



FERTILIZATION 



Another noteworthy point here is that if the two amoebae which en- 

 cyst together are derived from the same parent, the process is a case of 

 autogamy or pedogamy; if not, it is delayed hologamy. 



C D 



Figure l4l. Sappinia (Amoeba) diploidea. A, the binucleate vegetative form; B, two 

 such individuals (sister cells ?) encyst within a common capsule and in each amoeba 

 the two nuclei fuse together; C, the bodies of the two amoebae now unite, and the two 

 fusion nuclei undergo two "reduction divisions," C, D, after which the nuclei lie side 

 by side, as in A, throughout the vegetative period. (After Hartmann and Niigler, 1908.) 



The hfe history of the Foraminifera has been a subject of controversy 

 for many years. Since the pioneer researches of Lister (1895), which 

 were confirmed by Schaudinn (1903) and others, it has been generally 

 believed that the life history of Polysiomellma crispa is fairly repre- 

 sentative of the group. According to these investigators, alternation of 



