440 THE INHABITANTS OF THE SEA. 



seas, witb their currents and floods, and the various animals aDd 

 plants growing and thriving in their bosom. 



Who can tell when the last great revolutions of the earth-rind 

 took place, which, by the upheaving of mighty mountains or the 

 disruption of isthmuses, drew the present boundaries of land 

 and sea ? or who can pierce the deep mystery which veils the 

 future duration of the existing phase of planetary life ? 



So much is certain, that the ocean of the present day will be 

 transformed as the seas of the past have been, and that " all 

 that it inhabit" are doomed to perish like the long line of 

 animal and vegetable forms which preceded them. 



We know by too many signs that our earth is slowly but 

 unceasingly working out changes in her external form. Here 

 lands are rising, while other areas are gradually sinking ; here 

 the breakers perpetually gnaw the cliffs, and hollow out their 

 sides., while in other places alluvial deposits encroach upon the 

 sea's domain. 



However slowly these changes may be going on, they point to 

 a time when a new ocean will encircle new lands, and new 

 animal and vegetable forms arise within its bosom. Of what 

 nature and how gifted these races yet slumbering in the lap of 

 time may be, He only knows whose eye penetrates through all 

 eternity ; but we cannot doubt that they will be superior to the 

 present denizens of- the ocean. 



Hitherto the annals of the earth-rind have shown us uninter- 

 rupted progress; why, then, should the future be ruled by different 

 laws ? At first the sea only produces weeds, shells, Crustacea. ; 

 then the fishes and reptiles appear ; and the cetaceans close the 

 vista. But is this the last word, the last manifestation of oceanic 

 life, or is it not to be expected that the future seas will be 

 peopled with beings ranking as high above the whale or dolphin 

 as these rank above the giant saurians of the past ? 



