INTRODUCTION. 9 



After ten or twelve years of repose the branches have become 

 a foot or sixteen inches long, and are again ready for the 

 market. They vary much in price, according to the fineness 

 of their tints and the compactness of their structure, — the 

 finest bringing ten guineas an ounce, and the inferior ones 

 not above a shilling a pound. 



These Mediterranean corals hold as it were a middle 

 place betwixt our own tiny zoophytes, and the magnificent 

 corals of the great Pacific Ocean. The rate at which the 

 latter grow or increase in size has not yet been accurately 

 ascertained, though it is a matter which bears on questions 

 of considerable scientific importance. Some say that the 

 reefs on which their operations are carried on do not grow 

 above six inches in a hundred years ; others again say that 

 from their own observation they are convinced that they 

 grow a foot in a few years. The truth, it is probable, lies 

 between these statements. The rate of growth, as we have 

 said, of Mediterranean corals, has been ascertained with 

 considerable accuracy — not by scientific naturalists, but by 

 rough sailors, who find it their interest to know how often 

 their coral groves yield a fi*esh crop. Though the rate of 

 growth of our native zoophytes is in many cases matter of 

 uncertainty, yet as we find some of them a foot in height 



