260 TOILERS IN THE SEA. 



His rage was impotent : his wrath fulfill'd 



The counsels of Eternal Providence, 



And 'stablish'd what he strove to overturn : 



For every tempest threw fresh wrecks upon it ; 



Sand from the shoals, exuviae from the deep, 



Fragments of shells, dead sloughs, sea monsters' bones, 



Whales stranded in the shallows, hideous weeds 



HurPd out of darkness by the uprooting surges ; 



These with unutterable relics more, 



Heap'd the rough surface, till the various mass, 



By Nature's chemistry combined and purged, 



Had buried the bare rock in crumbling mould." 



At this stage it would be advisable to survey 



the distribution of coral reefs and atolls, or just as 



much as will be necessary to comprehend their 



general localisation. Bearing in mind that the coral 



itself has been dependent on the living organisms 



which constructed it, there will at once follow an 



admission that the temperature of the ocean must 



be high enough for the organisms to flourish, and 



here we arrive at the first condition which sets a 



limit to coral grounds. The reef corals can flourish 



in the hottest equatorial sea, hence there is no limit 



in that direction ; but it does not appear that they 



are able to bear a lower winter temperature than 



68 Fahr., which seems to be the boundary line on 



each side of the equator. We need not enter into 



the particulars why this line is a flexuous one, under 



the influence of oceanic currents, but so it is, that 



the line of temperature of the ocean at 68 in winter 



