80 



SEAWEEDS 



size. In the last-mentioned genus the stalk is long, 

 slender and solid at the base, but becoming hollow 

 and broader above ; near the top it expands into a 

 globular or elongate pear-shaped bladder, bearing 





Fio. 16. Macrocystis pyrifera. 

 phyllous leaves at base of stem, 

 Reduced. 



a, diagrammatic sketch of habit, the sporo- 

 b, apex of frond showing leaves splitting off. 



two bunches of leaves. In Macrocystis, the most 

 gigantic of all the forms, attaining frequently a 

 length greater than that of any other plants and 

 measuring hundreds of feet, the leaves are formed on 

 one side only of a scimitar-shaped blade by parallel 



