FILAMENTOUS GREEN ALG& 



243 



ciliated swimming spores are formed from the protoplasm of a 

 single cell. These escape, and after the swimming period come 

 to rest, germinate and produce the Ulothrix thread again. In 

 sexual reproduction similar biciliate swimming gametes are 



Fig. 187. 



Zoogonidia of (Edogonium escaping . 

 At the right one is germinating and 

 forming the holdfasts, by means of 

 which these algae attach themselves to 

 objects for support. (After Prings- 

 heim.) 



Fig. 1 86. 



Portion of thread of 

 ocdogonium, showing 

 chlorophyll grains, and 

 peculiar cap cell walls. 



Fig. 188. 



(Edogonium undulatum. with 

 ob'gonia and dwarf males; the 

 upper obgonium at the right has a 

 mature oospore. 



formed which unite in pairs to form zygospores (fig. 185). 

 Cladophora, Ch&tophora, Drapernatidia, etc., are branched forms 

 with a similar method of reproduction. 



378. (Edogonium. (Edogonium is an example of the second 

 kind of sexual reproduction. The thread like plant is simple. 



