THE KELPS 



209 



into a hollow float that rests on the surface of the water and 

 bears a number of strap-shaped leaves. The sea palm (Postelsia, 

 Fig. 197) is another remarkable form, with a thick, strong stalk 

 about a foot high, which bears a crown of small leaves and 

 somewhat resembles a palm tree in miniature. Macrocystis and 



FIG. 1H> 



FIG. 197 



FIG. 196. The sea otter's cabbage (Nereocystis) 

 Adapted from Postels and Ruprecht 



FIG. 197. The sea palm (Postelsia) 



Nereocystis grow in deep water, but the sea palms are found on 

 the rocks, where the surf breaks so heavily that the tough 

 elastic stems are bent over at right angles by the force of 

 every wave. 



The kelps reproduce by zoospores developed in one-celled 

 sporangia that are formed in large patches upon the leaves. 



