CORALS. 41 



and if left undisturbed, in the lapse of years successive generations deposit 

 such large quantities of calcareous matter as to form beds of considerable 

 thickness. , 



In the formation of their massive skeletons, it must be remembered that 

 /ife and death constantly keep pace with each other. The living mass, whilst 

 growing at the top, is with concurrent progress perishing beneath, leaving the 

 imperishable stone a still accumulating mound. With such a mode of increase, 

 there is no necessary limit to the growth of these Zoophytes. The rising mass 

 may expand upwards, until it nears the surface of the sea, when death ensues 

 simply from exposure, and not from any failure in its powers of life ; still 

 growing, round the margin of the rock itself has formed, it spreads on every 

 side. Old ocean raves to see a whole domain thus rescued from his grasp, 

 and piles upon the nascent island mud and weeds, which soon produce a 

 vegetable soil ; seeds brought by birds, and cocoa-palms, take root upon the 

 new-born surface, soon thick groves appear, inviting human occupation, and 

 man comes at last to take possession of a territory reared by the unaided 

 efforts of these humble creatures. 



Could we raise one of these islands from the sea, we should find the coral 

 reefs surrounding it like magnificent piles of artificial masonry resembling 

 ramparts, perhaps a hundred miles or more in circuit. 



Mr. Darwin has estimated the reefs of the Gambier group at 

 their outer limits to be two thousand feet in thickness. Some of 

 the coral-beds in the Pacific Ocean have a length of twelve hundred 

 and a breadth of three hundred and fifty or four hundred miles, 

 while another on the Australian coast is at least twelve hundred 

 miles long. Thus, therefore, at the bottom of the sea we find 

 materials plentiful enough wherewith to build, not islands only, 

 but whole continents, which only want upheaving to the surface 

 to become the abode of man ; and there is an agency at hand 

 whereby they can be raised. He who has climbed Vesuvius, or 

 scaled the lofty sides of thundering Etna, has had proof enough 

 that there is fire beneath the ground he treads upon , and that 

 this fire is widely spread, a single glance at any map will testify. 

 Through Europe, Asia, and the mighty chain, 



" Where Andes, giant of the western star, 

 With meteor standard to the winds unfurled, 

 Looks from his throne of clouds o'er half the world," 



each mountain tells us of volcanic power imprisoned deep beneath 

 its basis. Suppose, for a moment, that through some wide rent 

 the ocean found its way into this fiery gulf, and the imprisoned 

 stream, produced by such a dread catastrophe, putting its Titan 

 shoulders to the roof, heaved up the bottom of the sea, with all 

 its coral load ; mountains huge would raise 



" Their broad, bare backs into the sky," 



