41 



FIG. 2. , Plant of Fucus vesicuJosui, with air vesicles and fertile tips of 

 frond reduced ; b, male conceptacle of F. serratus ; c, female conceptacle ; 

 d, antheridia ; e, oogonium emerging from outer membrane ; /, oosphere, with 

 antherozoids. b, c, d, e, and /highly magnified. (After Thuret and Bornet.) 



