84 ZOOPHYTES. 
that break over them. The microscopic germ of a Gorgonia developes 
a polyp barely visible to the naked eye, which has the power of pro- 
ducing a secretion from its base. ‘The polyp buds, and finally the 
growing shrub is covered with branches and branchlets, many a 
mere thread in thickness, which stand and wave unhurt in the 
agitated waters. The same secretions fix it to its support, and so 
strongly, that even the rock comes away before the zoophyte will 
break from its attachment. ‘Tens of thousands of polyps cover the 
branches, like so many flowers, spreading their tinted petals in the 
genial sunshine, and quiet seas, but withdrawing when the clouds 
betoken a storm. 
“Excelsior” is the grave motto of the zoophyte. Ever upward, 
they continue growing and elongating, although death is at work 
below, with as rapid progress. A beautiful provision protects the 
branching coral-tree—often the work of ages—from being destroyed 
by the dissolving waters, when exposed, on the death and removal of 
the polyps. Certain minute incrusting corals—the Bryozoa and Ser- 
tularide, together with Nullipores—make the surface their resting- 
place, as soon as it is laid bare, and go on spreading and covering the 
dead trunk, and so prevent the wearing action of the sea. The 
Madrepore may thus continue to enlarge beyond its adult size; the 
Caryophyllia may multiply almost endlessly its cylindrical branch- 
ings, although the living animal but tips the extremities of each; for 
protection is given at once, when needed, and the polyps die, only to 
leave the surface to other forms of life, more varied and no less strange. 
Finally, the coral becomes subservient to a still higher purpose 
than the support of polyps and nullipores. ‘The debris, produced 
by the waves over a reef, settles into the many crevices among the 
dead trunks, and fills up the intervals, often large, between the scat- 
tered coral-patches ; and, by this combined action of living growth 
and detritus accumulations, a solid rocky basement is formed, and 
kept in constant increase. In this way the coral-reef gradually nears 
the surface, and finally becomes the foundation of one of the fairest of 
* The sea-girt isles, 
That, like to rich and various gems, inlay 
The unadorned bosom of the deep,” 
the coral polyps now yielding place to the flowers and groves of the 
land, which fulfil their end in promoting the comfort and happiness 
of man. 
