ANTHOZOA. 53 



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 sur- 

 face 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 unfurl'd, 

 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 gulph, and the imprisoned steam, pro- 

 duced 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," 



from which new rivers would descend to fertilize 

 another region of the globe. 



The Corals (Corallium)* properly so-called (Fig. 36), 

 have their central axis, which supports the external living 

 flesh, solid, without cells for the lodgment of the Polypes, 

 * Corallum, coral. 



