196 |fog S*rm0ns, (Essags, attb iJUimtos. [ix. 



Nor have these wonderful metamorphoses of sea into 

 land, and of land into sea, been confined to one corner 

 of England. During the chalk period, or "cretaceous 

 epoch," not one of the present great physical features of 

 the globe was in existence. Our great mountain ranges, 

 Pyrenees, Alps, Himalayas, Andes, have all been up- 

 heaved since the chalk was deposited, and the cretaceous 

 sea flowed over the sites of Sinai and Ararat. 



All this is certain, because rocks of cretaceous, or still 

 later, date have shared in the elevatory movements 

 which gave rise to these mountain chains ; and may 

 be found perched up, in some cases, many thousand 

 feet high upon their flanks. And evidence of equal 

 cogency demonstrates that, though, in Norfolk, the 

 forest-bed rests directly upon the chalk, yet it does so, 

 not because the period at which the forest grew imme- 

 diately followed that at which the chalk was formed, 

 but because an immense lapse of time, represented 

 elsewhere by thousands of feet of rock, is not indicated 

 at Cromer. 



I must ask you to believe that there is no less con- 

 clusive proof that a still more prolonged succession of 

 similar changes occurred, before the chajk was deposited. 

 Nor have we any reason to think that the first term in 

 the series of these changes is known. The oldest sea- 

 beds preserved to us are sands, and mud, and pebbles, 

 the wear and tear of rocks which were formed in still 

 older oceans. 



But, great as is the magnitude of these physical 

 changes of the world, they have been accompanied by 

 a no less striking series of modifications in its living 

 inhabitants. 



All the great classes of animals, beasts of the field, 

 fowls of the air, creeping things, and things which dwell 

 in the waters, flourished upon the globe long ages before 



