122 THE HARMONIES OF NATURE. 



welfare of the state. Linked together by an indissoluble chain, 

 five millions of individuals live together in peace and harmony 

 in one single porite of ten feet diameter a condition of tran- 

 quillity and ease which, no doubt, would soon give way to the 

 utmost anarchy if the tiny republicans were suddenly endowed 

 with human power of locomotion and human passions. 



Only the outer rind or superficial structure of the larger 

 corals is alive, for as the progress of growth piles new genera- 

 tions and new layers of chalk over their heads, the older polyps, 

 cut off from the sources of supply, and suffocated, as it were, by 

 their children, inevitably perish. But the skeleton, which they 

 secreted during life, remains as an indestructible record of their 

 existence, for while, with rare exceptions, the bones of the higher 

 animals vanish after a few years from the surface of the earth, 

 leaving no trace behind, the stone polyp, firmly rooted to the 

 spot which it occupied while alive, mocks the lapse of centuries, 

 and seems to bid defiance to all time. The coral-reefs of the 

 primitive world form a conspicuous portion of the earth-rind, 

 and as they are frequently situated in the depths of continents, 

 or beyond the limits of the polar circle, lead us back to times 

 when the tides broke against the mountains of Switzerland, or 

 the shores of Spitsbergen were washed by a tepid sea. 



The most ancient monuments erected by man to mark his 

 transient passage on earth the pyramids of Egypt or the 

 temples of Meroe do not reach perhaps beyond fifty or sixty 

 centuries; but here we have ramparts, to which the great wall of 

 China is a pigmy, erected at periods separated from the present 

 times by an incalculable series of ages. 



On submarine cliffs in the warmer seas, where the tempe- 

 rature of the water never sinks below 60 Fahr., the reef-build- 

 ing corals rear their wonderful palaces of stone. The depth to 

 which they can live does not exceed twenty or thirty fathoms ; 

 but as large areas of the sea-bottom on which they grow are 

 gradually subsiding, while their growth is at the same time con- 

 stantly tending upwards to the level of the lowest ebb, their 

 structures may in many places rise from vertical depths of 

 many hundred feet. The coral-reefs thus raised in the course 

 of ages by these minute and individually so puny architects 

 are frequently of truly colossal dimensions, stretch for hundreds 

 of miles along the coasts, fringe or encircle whole islands or 



