G. CORALLIUM. 225 



eight conical tentaciila, slightly compressed, and ci- 

 liated on their borders. 



Coral is found in difterent 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 



Co7\ 2 F 



