THE OCEANIC CORAL ISLAND SUBSIDENCE. 309 



ocean, just as if the subsidence increased in that direction. 

 Finally, the Atlantic beyond is water only, as if it had been 

 made a blank by the sinking of its lands. 



Thus the size of the islands, as well as the existence of 

 coral banks, and also the blankness of the ocean's surface, all 

 appear to bear evidence to a great subsidence. 



The peninsula of Florida, Cuba, and the Bahamas look, as 

 they lie together, as if all were once part of a greater Florida 

 or southeastern prolongation of the continent. The northwest- 

 ern and southwestern trends, characterizing the great features 

 of the American continent, run through the whole like a warp 

 and woof structure, binding them together in one system ; the 

 former trend, the northwest, existing in Florida and the Ba- 

 hamas, and the main line of Cuba ; and the latter course, the 

 west-southwest, in cross lines of islands in the Bahamas (one 

 at the north extremity, another in the line of Nassau, and 

 others to the southeast), in the high lands of northwestern 

 and southeastern Cuba, and in the Florida line of reefs, and 

 even further, in a submerged ridge between Florida and Cuba. 

 This combination of the two continental trends shows 

 that the lands are one in system, if they were never one in 

 continuous dry land. 



We cannot here infer that there was a regular increase of 

 subsidence from Florida eastward, or that Florida and Cuba 

 participated in it equally with the intermediate or ad- 

 joining seas ; for the facts in the Pacific have shown that 

 the subsiding oceanic area, had its nearly parallel bands of 

 greater and less subsidence, that areas of greatest sinking al- 

 ternated with others of less, as explained on page 326 ; and that 

 the groups of high islands are along the bands of least sinking. 

 So in the Atlantic, the subsidence was probably much greater 

 between Florida and Cuba than in the peninsula of Florida it- 



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