THE ALG^E. 



105 



water near the bank. The plant stem may be only a few 

 inches in length, or it may reach a length of some feet. 



FIG. 60. Cham fragilis. E is a single leaf, consisting of one cell and show- 

 ing the neutral line ; the arrows show the movement of the protoplasm in 

 cyclosis. B is a ripening antheridium. A is an archegonium showing the 

 mature egg cell surrounded by spiral cells and surmounted by a crown of 

 cells. D is a manubrium with its surrounding cells. At C are represented 

 the filaments of cells in which the antherozoids are produced. F and G 

 show the ciliated antherozoids after they have been set free. The cortical 

 cells on the stem are not shown in the figure. All are highly magnified. 



The diameter is seldom much greater than two or three 

 millimeters. 



The leaves grow in whorls from points on the stem 

 called nodes. The lengths of stem between the nodes 



