CnYPrOGAMS 



189 



minate. The short floating filaments, often much stoutei 

 than those of the Bread Mold, may be distinguished by 

 the naked eye. Under the microscope they are seen to 

 compose an nnseptate branching mycelium, which pene- 

 trates the object upon which it grows. 



449. Rep rod net to II. — The more or less swollen ends of 

 some branches are seen to be filled with dense protoplasm 

 and to be cut off by 

 septa to form the A \ffl 

 zoosporaiu/ia (Fig. 

 308, a). The con- 

 tents finally breaks 

 up into numer(nis 

 rounded bodies which 

 finally escape from a 

 terminal opening in 

 the zoosporangium. 

 These bodies, the zoo- 

 spores, in some spe- 

 cies are motile from 

 the time they are set 

 free ; in other species 

 just after ejection 

 they surround them- 

 selves by a delicate 

 cell wall, from which 

 they soon escape and 

 swim away, soon to 

 germinate. 



450. Resting oo- 

 spores are formed 

 from egg cells, pro- 

 duced in spherical 

 oogonia (Fig. 308, 

 d), fertilized from 

 antheridial tubes (Fig. 309), which penetrate the oogonial 

 wall in order to reach the egg cells. After fertilization 

 the oospore surrounds itself with a thick wall. 



308. 



Water Mold: A, zoosporangium; B, es- 

 caped zoospores, belore becoming motile ; 

 C, zoospores in tlie active stage; /', 

 oogonia and antlieridia (a) . Tlie lower 

 oogonium contains an unfertilized egg 

 cell (e), and two young oospores (o) ; the 

 uioper sliows four mature oospores (sp). 



