37i) CORALS AND COBAL ISLANDS. 



self; and greater along the Caribbean Sea parallel with Cuba, 

 as well as along the Bahama reefs, than in Cuba. 



The position of the lonely Bermuda atoll confirms these 

 deductions. Its solitary state is reason for suspecting that 

 great changes have taken place about it; for it is not na- 

 tural for islands to be alone. The tongue of warm water 

 due to the Gulf Stream, in which the Bermudas lie, is nar- 

 row, and an island a hundred miles or more distant to the 

 northeast-by-east, or in the line of its trend (p. 219), if 

 experiencing the same subsidence that made the Bermuda 

 land an atoll, would have disappeared without a coral mon- 

 ument to bear record to its former existence. Twenty miles 

 to the southwest-by-west from the Bermudas, there are two 

 submerged banks, twenty to forty-seven fathoms under water, 

 showing that the Bermudas are not completely alone, and 

 demonstrating that they cover a summit in a range of heights ; 

 and it may have been a long range. 



In the Indian ocean, again, there is evidence that the coral- 

 island subsidence was one that affected the oceanic area more 

 than the adjoining borders of the continent, and most, the 

 central parts of the ocean. For, in the first place, the Archi- 

 pelago of the Maldives narrows and deepens to the south- 

 ward (p. 186). Further, the large Chagos Group, lying to the 

 south of the Maldives, contains but very little dry land in any 

 of its extensive reefs, while some of them, including the 

 Great Chagos Bank, are sunken atolls. Again, still other 

 large reefs nearly bare, lie to the southwest of the Chagos 

 Group; while Keeling's is another outlying atoll southwest 

 of southern Sumatra and far out toward mid-ocean. 



The probability is, therefore, that both the central Atlantic 

 and Indian Oceans were regions of this subsidence, like the 

 central Pacific, and that the absence of islands, over a large 



