38 



HALF AN HOUR WITH SEAWEEDS. 



ingly curious, and well worth a little further 

 consideration. Each of the little frustrules has a 

 minute opening, through which their contents escape. 



Fig. 8. 



\ 



Serrated Wrack (Fucus serratus). 



If we cut one of these tips or tubercles across, then 

 each frustrule will be seen representing a cell or 

 internal cavity, enclosing, in one plant, what are 

 called antheridia, and, in another, the spores (see 



