384 THE BOTTOM OF THE SEA. 



day, and we see their soft gelatinous bodies, aided by 

 the law of vitality, quell the brute power of tlie 

 waves, against vvhicli neither the industry of man 

 nor the inanimate forces of nature would be able to 

 struggle with success. 



Life, apparently weak and mean, but in reality 

 active and full of resources, issues victorious from an 

 incessant struggle, in which inert matter threatens 

 momentarily the destruction of the frail enemy whose 

 strength she continually feeds. Coral insects prefer 

 a current of water. It carries away from them the 

 matters rejected or secreted by their bodies, and be- 

 come innutritions, or even as dangerous to them as 

 poisons. The calm reigning in deep \\ ater is death 

 to these minute animals. 



The coral polypi live near the surface : according 

 to Darwin and Dana, they never build at a depth ex- 

 ceeding forty yards, whilst other species live at much 

 greater depths, even reaching to 400 yards. How, 

 then, can we explain the great depth to which some 

 of the larger coral banks, like those of the Fiji Islan<^s, 

 descend ? Darwin has discovered a simple explana- 

 tion of this fact. Founded on numerous observa- 

 tions, it entirely accords with wiiat geology teaches 

 us respecting the crust of the globe. 



Since the coral insect does not live out of the water, 

 the growth of the reef cannot go on above its surface. 



