104: INSTINCT OF THE BOCK BUILD HIIS. 



To protect their dwellings from the violent storms by 

 which the waters of the deep are frequently agitated, they 

 erect a breastwork, which effectually shields them from 

 wind and wave. In the early stages of their operations they 

 work perpendicularly, so that the highest part of the coral 

 wall, on reaching the surface, is on the windward side, 

 and affords protection to the busy laborers in their opera- 

 tions. These breastworks, or breakwaters, w^ill resist more 

 powerful seas than if formed of granite, rising as they do fre- 

 quently from a depth of a thousand or fifteen hundred feet, 

 and adapted in a way that no human skill or foresight could 

 equal to the utmost powers of the heavy billows that contin- 

 ually lash against them. 



Another observation we may make on this subject, is, 

 that in one species a remarkable arrangement is found ; the 

 upper openings of the cells in which they live, have a vase- 

 like form, shutting with a lid : when the animal wishes to 

 expand itself, it opens the lid like a trap-door, and protrudes 

 itself; and when it re-contracts itself and retreats, the lid 

 falls and closes the aperture so exactly that the animal is 

 perfectly protected. 



Coral differs in quality and color. The common Red 

 Coral which is used for many ornamental purposes, and is 

 so much admired for its fine color, is chiefly obtained from 

 the Mediterranean, in some parts of which extensive " fish- 

 eries " are carried on. It is brought up from the depths of 

 the sea by means of a kind of grappling apparatus dragged 

 after a boat, the pieces being broken from the bottom by 

 beams of wood wliich are sunk by weights, and then en^ 

 tangled among hemp. Great care is necessary to preserve 

 the pieces from being lacerated. Red coral has a shrub-like 

 branching form, and grows to the height of about a foot, with 

 the thickness of a little finger. Much of the coral obtained 

 from the Mediterranean is sent to India, where it is much 

 prized by the natives. Many of the arms and horse-capari- 



