14 Postelsia 
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 subjected to heavy wave action and 
surf, it has become necessary to devise a scheme 
for holding the seed in place until the young 
plant has 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-lke 
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 cel grasses, but 
