G. CORALLIUM. 
225 
eight conical tentacula, slightly compressed, and ci- 
liated on their borders. 
Coral is found in different parts of the Mediterra- 
nean and in the Red Sea : it grows in all directions, 
and each trunk forms a perpendicular to the level 
from whence it springs. 
Coral attaches itself to all hard rocks, whatever 
may be their nature ; it is also found on unfixed 
bodies, such as fragments of lava, of stone vases, or 
broken glass, and it is even seen, in the cabinets of 
naturalists, adhering to human skulls. 
When the Coral is once detached, and at the mercy 
of the waves, it soon loses its polypiferous rind ; to 
enable the constructors of this brilliant edifice to 
labor for its increase, it is necessary that it should be 
fixed. Their work does not advance with a rapidity 
equal to that of the madreporic polypi in the Indian 
sea, or the immense Eastern Ocean, whose labors, in 
the short space of a few years, close the entrance of 
ports, and raise immense reefs, on which many ves- 
sels, sailing in those distant regions, strike and perish. 
Eight or ten years, at a moderate depth, are requisite 
for the Coralline Polypi to raise their habitation to the 
height of two or three decimetres, an extent it never 
surpasses, whatever may be the age of the Polypidom. 
Arrived at this degree of growth, it widens, though 
very slowly, and soon, pierced on all sides by those 
destructive worms which even attack the hardest 
rocks, it loses its solidity, and the slightest shock 
detaches it from its base : becoming then the sport of 
the waves, the polypi perish, and leave exposed its 
brilliant stem, which, cast upon the shore, loses its 
Cor. 2 f 
