102 



ISLAND LIFE. 



[part I. 



comparatively shallow water formation — that is, one formed at a 

 depth measured by hundreds rather than by thousands of 

 fathoms. The nature of the formations composing all our 

 continents also proves the continuity of those continents. Every- 

 where we find clearly marked shore and estuarine deposits, 

 showing that every part of the existing land has in turn been 

 on the sea-shore ; and wc also find in all periods lacustrine for- 

 mations of considerable extent with remains of plants and land 

 animals, proving the existence of continents or extensive lands, 

 in which such lakes or estuaries could be formed. These lacus- 

 trine deposits can be traced back through every period, from the 

 newer Tertiary to the Devonian and Cambrian, and in every 

 continent which has been geologically explored ; and thus com- 

 plete the proof that our continents have been in existence under 

 ever changing 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 addi- 

 tion to their enormous depths and great extent, and the circum- 

 stance 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) never contain any Palseozoic 

 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 ! The exceptions are New Zealand 

 and the Seychelles Islands, both situated near to continents, 

 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. 



