302 CORALS AND CORAL LSL.ANDS. 



There is also no evidence, in any part of any ocean, that there 

 is a set of cold-water corals fitted to commence a reef in deep 

 water and build it up to such a level that another set of species 

 may take it and carry it up higher ; the facts thus far gathered 

 are all opposed to such an idea. Should it be hereafter proved 

 that the corals of the inferior beds differ in species from those 

 now existing, it will probably be found that the predecessors of 

 those now living were also shallow- water species ; so that the 

 subsidence in any case was necessary. 



V. DEEP-SEA LIMESTONES SELDOM IF EVER MADE FROM CORAL 

 ISLAND OR REEF DEBRIS. 



This point has been discussed on pages i [4, 173. The facts 

 show that the sediment or debris from a shore is almost wholly 

 thrown back by the waves against the land where it originated, 

 or over its submerged part in the shallow waters, and that it 

 is not transported away to make deep-sea formations. 



The facts have also a wider bearing, for they teach that lands 

 separated by a range of deep ocean cannot supply one another 

 with material for rocks. The existence of an Atlantic ocean 

 continent — an Atlantis — has sometimes been assumed in order 

 to make it a source of the mud, sand and gravel, out of which 

 the thick sedimentary formations of the Appalachian region of 

 North America were made. But if this Atlantis were a reality, 

 there would still have been needed, in addition to the presence 

 of such an ocean continent, a set of freight-carriers that could 

 beat off the waves from their accustomed work, and push aside 

 the ordinary oceanic currents ; or else Atlantis would get back 

 all its own dirt. 



VL ABSENCE OF FOSSILS FROM LIMESTONE STRATA. 



Absence of fossils has been mentioned as a frequent char- 

 acteristic of the fine compact coral reef-rock, and also of the 

 beach and drift sand-rock or oohte (pp. 122, 158). The rocks 

 are formed at the sea-level, and in the midst of abundant life, 



