IMPERFECTION OF GEOLOGICAL RECORD 269 



with its numerous large islands separated by wide and 

 shallow seas, probably represents the former state of 

 Europe, whilst most of our formations were accumu- 

 lating'. The Malay Archipelago is one of the richest 

 regions of the whole world in organic beings ; yet if all 

 the species were to be collected which have ever lived 

 there, how imperfectly would they represent the natural 

 history of the world ! 



But we have every reason to believe that the terres- 

 trial productions of the archipelago would be preserved 

 in an excessively imperfect manner in the formations 

 which we suppose to be there accumulating. I suspect 

 that not many of the strictly littoral animals, or of 

 those which lived on naked submarine rocks, would 

 be embedded ; and those embedded in gravel or sand, 

 would not endure to a distant epoch. Wherever sedi- 

 ment did not accumulate on the bed of the sea, or where it 

 did not accumulate at a sufficient rate to protect organic 

 bodies from decay, no remains could be preserved. 



I believe that fossiliferous formations could be formed 

 in the archipelago, of thickness sufficient to last to an 

 age as distant in futurity as the secondary formations 

 lie in the past, only during periods of subsidence. 

 These periods of subsidence would be separated from 

 each other by enormous intervals, during which the 

 area would be either stationary or rising; whilst rising, 

 each fossiliferous formation would be destroyed, almost 

 as soon as accumulated, by the incessant coast-action, 

 as we now see on the shores of South America. During 

 the periods of subsidence there would probablv be 

 much extinction of life ; during the periods of eleva- 

 tion, there would be much variation, but the geological 

 record would then be least perfect. 



It may be doubted whether the duration of any one 

 great period of subsidence over the whole or part of 

 the archipelago, together wih a contemporaneous accu- 

 mulation of sediment, would exceed the average dura- 

 tion of the same specific forms ; and these contingencies 

 are indispensable for the preservation of all the transi- 

 tional gradations between any two or more species. If 



