Cro *by.] 476 [November 7, 



mountains are original corrugations of the earth's crust, formed 

 perhaps, before the advent of oceans and stratified rocks, is 

 equally gratuitous and baseless. 



As an argument in favor of the permanence of continents and 

 oceans, Mr. Wallace attaches great importance to the supposed 

 fact, first mentioned by Darwin, that, with the exception of New 

 Zealand, and the Seychelles Islands in the Indian Ocean, none of 

 the truly oceanic islands contain either Paleozoic or Mesozoic 

 rocks ; the inference being that during the Paleozoic and Meso- 

 zoic eras neither continents nor continental islands existed where 

 our oceans now extend, for had they existed Paleozoic and Meso- 

 zoic formations would in all probability have been accumulated 

 from sediment derived from their wear and tear. 



This argument is not so formidable as it at first appears. Mr. 

 Wallace thinks it is doubtful if New Zealand can be properly 

 called a true oceanic island. But it is difficult to see how it can 

 be differently classified, since the ocean between it and Australia 

 is one thousand miles broad and three miles deep. But there are 

 other exceptions to the law which he formulates. New Cale- 

 donia is an oceanic island, over 700 miles of deep water separat- 

 ing it from Australia, while the sea in its near neighborhood has 

 a depth of 15,000 to over 17,000 feet ; and yet it is composed of 

 stratified crystalline, Paleozoic and Mesozoic rocks. The Salo- 

 mon Islands, 500 miles from New Guinea and nearly twice that 

 distance from Australia, are, according to Garnier, composed of 

 rocks similar to those found in New Caledonia, Kerguelen Island, 

 in the southern part of the Indian Ocean, and 2,000 miles from 

 the nearest continent, is certainly a true oceanic island ; and 

 yet it is composed, in a large part, of stratified rocks, both 

 fossiliferous and crystalline. The Philippine Islands contain 

 Secondary, if not Paleozoic, strata; and, although only 300 

 to 500 miles from Borneo and the continent of Asia, they are 

 surrounded on all sides by water from two to three miles deep. 

 Naturalists are generally agreed that the true borders of the con- 

 tinents are not the actural shore-lines, but the lines, sometimes 

 100 to 200 miles from shore, where the water commences to 

 deepen rapidly and the abysses of the ocean begin. All land be- 

 yond this true continental edge is oceanic. Now, judged by this 

 criterion, the Philippines are, apparently, oceanic islands. It is 



