112 



PRACTICAL BOTANY. 



FIG. til. Fucus vesiculosus. An entire frond is represented, the lower part 

 at C, the upper part at D. At C is seen the disk by which the plant was 

 attached to a rock or other support. At M are seen the enlarged ends of 

 branches bearing the conceptacles in which the reproductive cells are pro- 

 duced. At 6, antheridia with paraphyses are represented ; at c, an oogo- 

 nium with paraphyses ; at d, a ripened oogonium with egg cells ready to 

 burst forth. 



The sexual reproduction is better understood. Certain 

 branches become swollen at the ends. In these enlarge- 

 ments the sexual organs develop. The antheridia may be 



