I. 



The Permanence of the Great Oceanic Basms. 



THAT the great Oceanic Basins, as well as the land areas of the 

 globe, have persisted throughout a large portion, if not the 

 whole, of known geological time, is a proposition which has been 

 accepted by writers of such eminence, and is supported by so many 

 distinct lines of evidence, that it seemed likely to become one of the 

 established teachings of geology. Professor Dana was led to it by a 

 study of the development of the North American Continent ; Darwin 

 upheld it from his study of Oceanic Islands, and the facts he adduced 

 have since been strengthened by the discovery that the two supposed 

 exceptions to the generalisation that no ancient sedimentary rocks 

 occur on such islands — Rodriguez and St. Paul's Rocks — are no 

 exceptions at all. Two successive heads of the Geological Survey of 

 Great Britain, Sir Andrew Ramsay and Sir Archibald Geikie, have 

 advocated similar views ; while Mr. John Murray, of the " Challenger," 

 holds that the vast mass of evidence now accumulated as to the 

 nature of the deposits on the floors of the great oceans, indicates that 

 they are distinct in character and origin from any of the widespread 

 formations which make up the series of the sedimentary rocks. 

 Coming to the subject from a totally different point of view, that of 

 the physicist and mathematician, the Rev. Osmond Fisher arrives at 

 similar results. In the latest issue of his important work, 

 " Physics of the Earth's Crust," he gives as one of his conclusions — 

 " and lastly, that the great oceanic and continental areas have never 

 changed places " ; and, in the summary of the whole work, he says : 

 " The occupation of an entire hemisphere by one great ocean is a 

 remarkable circumstance, and we have seen reason for believing that 

 this is a very ancient division of the surface, and that it is probably 

 a mistake to suppose that every part of it has been sometimes raised 

 above the sea, and sometimes depressed beneath it. The truth seems 

 to be, that the region subject to these alterations of conditions does 

 not extend very far away from the present coast lines." 



When studying the causes which have brought about the 

 geographical distribution of animals, I was compelled to deal with 

 this question, because I found that it had been the custom of many 

 writers to solve all anomalies of distribution by the creation of hypo- 

 thetical lands, bridging across the great oceans in various directions 



