EMPLOYxAIENT OF COKAL BUILDEES. 95 



independently of tlie ratio of growth. There are facts 

 on record, however, which imj^ly that, in certain circum- 

 stances, the process is rapid. A channel that had been 

 dug through the reef of Keeling Atoll for the passage 

 of a schooner, that had been built on the island, from the 

 lagoon into the sea, was found ten years afterwards to be 

 almost choked up with living coral. An interesting 

 experiment was tried at Madagascar, by securing several 

 masses of living coral by stakes three feet below the sur- 

 face. Seven months afterwards they were found nearly 

 reaching to the surface, firmly cemented to the rock, 

 and extended laterally several feet ; a remarkably rapid 

 growth ! 



An ingenious inquiry has been started, whether the 

 coral polypes may not yet be employed by man for the 

 construction of sea-walls and reefs, in places within or 

 near the tropics, where they are needed. Professor 

 Asjassiz has shewn that it is not difficult to obtain livino: 

 specimens of the zoophyte, and to preserve them, so as to 

 study at leisure their habits and motions. Why, then, 

 it has been asked, as we emj^loy the silk-worm, and 

 furnish it with food and material to spin for us our silks, 

 and as we plant and form beds of oysters in favourable 

 locations, where we please, may we not also employ the 

 agency of the coral lithophyte, to lay the foundations, for 

 instance, of a lighthouse, or to form a breakwater where 

 one is needed ? Such a practical result is by no means 

 improbable, from the minute and scientific observations 

 now making upon these busy little builders of the deep.* 



* Cheever's Sayidivich Islands, Appx., p. 310. 



