440 THE INHABITANTS OF THE SEA. 
seas, with their currents and floods, and the various animals and 
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 cr doiphin 
as these rank above the giant saurians of the past ? 
