92 THE ORIGIN OF SPECIES 



views here entertained. To show that it may hereafter 

 receive some explanation, I will give the following hy- 

 pothesis. From the nature of the organic remains which 

 do not appear to have inhabited profound depths, in the 

 several formations of Europe and of the United States; 

 and from the amount of sediment, miles in thickness, of 

 which the formations are composed, we may infer that 

 from first to last large islands or tracts of land, whence 

 the sediment was derived, occurred in the neighborhood 

 of the now existing continents of Europe and North 

 America. This same view has since been maintained 

 by Agassiz and others. But we do not know what was 

 the state of things in the intervals between the several 

 successive formations; whether Europe and the United 

 States during these intervals existed as dry land, or as 

 a submarine surface near land, on which sediment was 

 not deposited, or as the bed of an open and unfathom- 

 able sea. f 



Looking to the existing oceans, which are thrice as 

 extensive as the land, we see them studded with many 

 islands; but hardly one truly oceanic island (with the 

 exception of New Zealand, if this can be called a truly 

 oceanic island) is as yet known to afford even a remnant 

 of any paleozoic or secondary formation. Hence we may 

 perhaps infer that, during the paleozoic and secondary 

 periods, neither continents nor continental islands existed 

 where our oceans now extend; for had they existed, 

 paleozoic and secondary formations would in all prob- 

 ability have been accumulated from sediment derived 

 from their wear and tear; and these would have been 

 at least partially upheaved by the oscillations of level, 

 which must have intervened during these enormously 



