IV.] FOUNDATION OF A THEORY OF HEREDITY. 207 



I. Pandorina mornm (after Pringsheim), a swarming colony. 

 II. A colony divided into sixteen daughter colonies ; all the 

 cells alike. III. A young individual of I'ohwx luiuor (after 

 Stein), still enclosed in the wall of the cell from which it has 

 been parthenogeneticaily produced. The constituent cells are 

 divided into somatic cells (^sz), and germ-cells {_kz). 



