A GAl continued.- CLASSIFICATION. 



169 



The fruiting portions are somewhat thickened as shown in the hgure. 

 Within these portions are numerous oval cavities opening by a circular pore, 

 which gives a punctate appearance to these fruiting cushions. Tufts of hairs 

 frequently project through them. 



365. Structure of the conceptacles. — On making sections of the fruiting 

 portions one finds the walls of the cavities covered with outgrowths. Some 

 of these are short branches which bear a large rounded terminal sac, the 



Fig. 175. 

 Portion of plant of Fucus show- 

 ing conceptacles in enlarged ends ; 

 and below the vesicles (Fucus 

 vesiculosus). 



Fig. 176. 

 Section of conceptacle of Fucus, showing 

 oogonia, and tufts of an.heridia. 



oogonium, at maturity containing eight egg cells. !More slender and much- 

 branched threads bear narrowly oval antheridia. In these are developed 

 several two-ciliated spermatozoid,^-. 



366. Fertilization. — .At maturity the spermatozoidsand egg cells float out- 

 side of the oval ca^dties, where fertilization takes place. The spcrmatozoid 



