GROWTH OF CORAL-ISLANDS. 145 



the seat of attachment of the young of the neigh- 

 bouring corals, the successive generations of which, 

 by their rapid growth, and development of their cal- 

 careous skeletons, soon repair the damage caused by 

 the storm. The masses of broken coral, thus driven 

 inwards towards the lagoon, accumulate in time to 

 the height of some feet above high water. These 

 fragments are mixed with sand and shells, and form 

 a favourable soil for the growth of vegetables, such as 

 the cocoa-palms, the large nuts of which may be borne 

 hither by currents of the ocean from very distant 

 shores. Turtles likewise float to the nascent island, 

 browse on the sea-weeds that grow in the lagoon, and 

 breed there. Numerous species of fishes and shell- 

 fish flourish in the same still water, which abounds 

 with animal life. Man comes at last and takes pos- 

 session of the island, and the cocoa-nut, the turtle, 

 and the fish, afford him abundant and wholesome 

 food : 



" The turf looks green where the breakers roll'd, 

 O'er the whirlpool ripens the rind of gold ; 

 The sea-snatch' d isle is the home of men, 

 And mountains exult where the waves have been." 



But it may be asked, how does he supply himself 

 with that necessary of life, fresh water ? This is ob- 

 tained in a very simple and unexpected manner, from 

 shallow wells dug in the calcareous soil, which ebb 

 and flow with the tides, and yet are almost wholly free 

 from the saline particles of the ocean. Some have 

 supposed that the sea-water loses its peculiar salts by 

 infiltration through the calcareous mass. Mr. Darwin 

 thinks that it is derived from the rain-water, which, 



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