14 ipostelsia 



pools which empty either only partly or else 

 almost entirely with the outgoing tide, the grass 

 is found attached both on the sides and at the 

 bottom. 



The manner of seed distribution of a plant 

 which has adopted this habitat is one of con- 

 siderable interest. Growing as the plant does 

 in places sul^jected to heavy wave action and 

 surf, it has become necessary to devise a scheme 

 for holding the seed in place until the young 

 ])lant lias anchored itself by its roots. It is af- 

 fected in the following manner. At the time of 

 maturity the uni-carpellate fruits are oblong 

 bodies with two emergences or projections to- 

 wards the base. As they are washed about on 

 the rocks, the softer outer tissue of these pro- 

 jections wears away so as to expose the harder, 

 inner portions in the form of two fish-hook-like 

 prongs. By means of these it is finally able to 

 grapple on to some algal holdfast or other likely 

 object, thus bringing the body to rest and per- 

 mitting the germinating seed to attach its rootlets 

 to the substratum. 



Another representative of the eel grasses, but 



