No. 422.] PHYLLOSPADIX AS A BEACH-BUILDER. 103 
the body of it as in a sling of tough, compact tissue, com- 
posed of elongated lignified cells. Further, this endocarp, 
prolonged downward, forms the axes of the arms; and, finally, 
it produces a great number of very long and thick-walled 
cells, which lie loosely imbedded in the softer substance of 
the “fin” (f). These “fibers” may be easily separated from 
one another, and from the enclosing exocarp, except at their 
lower ends, where they are conjoined with the endocarp of the 
arms. These slender lignified cells are the Fasern of Ruprecht, 
and now it is to be inquired how i 
they are metamorphosed into the a 
barbs of Fig. 3. 


2. -tesla 
= ps "i -endocarp 
When the ripe fruit is ready to [ uw" 
break loose from the spadix, its 
arms have grown longer and Dex 
: ; . grammatic 
stiffer, as in Fig. 3, but are still, section of 
of course, enclosed in the exo- 
carp. Now the fruit begins 
to drift about, — flung against the rocks, washed up on the 
beach, and sucked back again, bruised and scoured, in the 
swirling sand and pebbles of the undertow; and after a little 
of this rough-and-tumble existence the spongy exocarp begins 
to wear away, leaving exposed, in the arms and about the upper 
part of the seed, the hard endocarp, while about the base (7.¢., 
the lower middle part of Fig. 3) there is laid bare the smooth 
surface of the shell-like testa. But the important point is that 
the exocarp in which the barbs are imbedded is also got rid of. 
It easily flakes off and is washed away, and then, with a little 
more sand-scouring, the freed barbs, springing apart a little, 
stand out clean, like so many whalebones. 
Now our “anchoring mechanism” is uncovered and ready for 
use. By this time, too, the seed may be ready to pe 
and, for the safe putting forth of leaves, a fixed abiding place 
is necessary. The seed must be anchored, and, the e 
being ready, the next requisite is a suitable anchoring groun 
‘Along our coast there are various species of coralline hend 
weeds (Corallina, Amphiroa) which abound wherever t 
are rocks between tidelines. These alge have slender, 
