CHAP. VI GEOGRAPHICAL AND GEOLOGICAL CHANGES 105 



forms throughout the whole of that enormous lapse of 

 time. 



On the side of the oceans we have also a great weight 

 of evidence in favour of their permanence and stability. 

 In addition to their enormous depths and great extent, 

 and the circumstance that the deposits now forming in 

 them are distinct from anything found upon the land- 

 surface, we have the extraordinary fact that the countless 

 islands scattered over their whole area (with one or two 

 exceptions only and those comparatively near to continental 

 areas) never contain any Palaeozoic or Secondary rocks — 

 that is, have not preserved any fragments of the supposed 

 ancient continents, nor of the deposits which must have 

 resulted from their denudation during the whole period of 

 their existence ! TLe supposed exceptions are New 

 Zealand and the Seychelles Islands, both situated near 

 to continents and not really oceanic, leaving almost the 

 whole of the vast areas of the Atlantic, Pacific, Indian, 

 and Southern oceans, without a solitary relic of the great 

 islands or continents supposed to have sunk beneath their 

 waves. 



Since the last edition of this book appeared, I have 

 added two other general arguments to those here adduced 

 indicating the extreme improbability, if not the impossi- 

 bility, of the great oceanic areas ever having been con- 

 tinents. The one depends on the contours of the ocean 

 floors, now fairly well known, and presenting a radical 

 difference from that which they would present had they 

 been submerged continental land. The other is founded 

 on the almost identical range and completeness of the 

 geological series of formations in all the great continents. 

 These arguments are set forth in my Studies Scientific and 

 Social, vol. i., chap. 2, and, in combination with those here 

 adduced, will, I think, carry conviction to most students 

 of the subject. 



