150 BOTANY. 



tition, and in it very small biciliate antherozoids are de- 

 veloped in great numbers. The female organ (oogone) is 

 short and ovoid in outline, and usually stands near the 

 male organs. In it a partition forms near its point of 

 union with the main tube; the upper portion becomes an 

 oogone, and its protoplasm condenses into a rounded body, 

 the germ-cell : at this time the wall of the oogone opens. 



Fig. 78. — Reproduction of green felt (Vaucheria sessilis"). A^ formation 

 of a zoospore ; B, zoospore come to rest ; C, zoospore germinating ; X), E, 

 young plants ; w, root-like holdfasts ; ¥., plant with sexual organs. Mag- 

 nified sibout 30 times. 



and permits the entrance of the antherozoids which were 

 set free by the rupture of the antherid-wall. 



267. Upon coming into contact with the germ-cell the 

 antherozoids mingle with it and disappear; the germ-cell 

 immediately begins to secrete a wall of cellulose about 

 itself, and it thus becomes a resting spore. After a period 



