2 14 



THE GERM-PLASM 



differentiated into somatic cells and germ-cells. The hetero- 

 plastid genus I'oh'ox must have arisen phyletically from a 

 homoplastid form : but we can hardly imagine that there can be 



Fig. 17. — I. Pandoritia iiiorni:;. — A colony of swarming cells. II. A colony 

 which has given rise to dangliter-colonies: — all the ceils are similar to one 

 another. (After Pringsheini.) III. A young individual of I'ohw.v minor, still 

 enclosed within the parent (after Stein) : the cells are diflerentiated into somatic- 

 and germ-cells. 



