POLYPES. 185 



conversion into one vast plain, yielding forests 

 of bread-fruit and other trees, and ultimately 

 sustenance to a numerous population, and a 

 variety of animals subservient to their use, but 

 taking a wider range and still further enlarging 

 its view, might behold the tropical portion of the 

 vast pacific, not only studded with these islands, 

 but exhibiting them in such frequent clusters 

 and so large as almost to form a kind of bridge 

 of communication between Asia and America. 

 Indeed, at present, we know not how far these 

 founders of islands may have been concerned 

 in rearing a considerable portion of those conti- 

 nents that form the old world. Calcareous strata 

 and ridges occur every where, and though other 

 causes may have contributed to their formation, 1 

 yet it is not improbable, that at the time when 

 our northern climates were inhabited by tropical 

 animals, our seas also might abound in madre- 

 pores, &c. which might bear their part in the 

 erection .of some of our islands. 



Professor Buckland, in the appendix to Cap- 

 tain Beechey's Voyage, states that even within 

 the arctic circle there are spots that can be shewn 

 to have been once the site of extensive coral 

 reefs. The old coral reefs that existed previously 

 to the deluge, by that great catastrophe, in many 

 cases might be formed into chalk ridges. This 

 indeed seems proved by the remains of marine 

 1 See Ly ell's GeoL 1. 130. 210. 



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