DESCRIPTIONS 
OF 
iat FOS 5 Lis 
FROM 
BRACKLESHAM BAY, SELSEY AND BOGNOR. 
ZOOPHYTA. 
A rew words may be interesting on the peculiar structure of Coral, as the small 
creatures or Polypes which excrete this substance seldom come under considera- 
tion, though their influence on the earth’s surface is not inferior to that of any 
class of animals. The coral islands and reefs in the Pacific and other tropical 
seas are the monuments of their past and present industry, or, in other words, 
the accumulation of their calcareous skeletons. Mr. Darwin, speaking of the 
great durability of these islands, which are able to resist the most violent action 
of the waves, beautifully observes in his ‘ Journal,’ p. 548 :—“‘‘ It is impossible to 
behold these waves without feeling a conviction that an island, though built of 
the hardest rock, let it be porphyry, granite, or quartz, would ultimately yield 
and be demolished by such irresistible forces. Yet these low, insignificant coral 
islets stand and are victorious ; for here another power, as antagonist to the 
former, takes part in the contest. The organic forces separate the atoms of car- 
bonate of lime one by one from the foaming breakers, and unite them into sym- 
metrical structure. Let the hurricane tear up its thousand huge fragments ; yet 
what will this tell against the accumulated labour of myriads of architects, at 
work night and day, month after month? Thus do we see the soft and gelati- 
nous body of a polypus, through the agency of the vital laws, conquering the 
great mechanical power of the waves of an ocean, which neither the art of man, 
nor the inanimate works of nature could successfully resist.”” Large formations 
of fossil limestone are the result of the prodigious multiplication of Polypiferous 
animals continued over untold ages. 
It appears that the animal has usually the power of excreting from the inferior 
portion of its surface a large quantity of calcareous matter, which is deposited 
