IV.] FOUNDATION OF A THEORY OF HEREDITY. IQ-J 



i 



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

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

 cells alike. III. A young individual of Volvox minor (after 

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

 been parthenogenetically produced. The con'^tituent cells are 

 divided into somatic cells {sz), and germ-cells {kz). 



