94 ORGANIC REMAINS. 



SO many centuries in ignorance of the fact, which is now 

 so fully demonstrated, that no small part of the present 

 surface of the earth is derived from the remains of animals, 

 that constituted the population of ancient seas. Many ex- 

 tensive plains and massive mountains form, as it were, the 

 great charnel-houses of preceding generations,' in which the 

 petrified exuvia3 of extinct races of animals and vegetables 

 are piled into stupendous monuments of the operations of 

 life and death, during almost immeasurable periods of past 

 time. " At the sight of a spectacle," says Cuvier,* " so im- 

 posing, so terrible as that of the wreck of animal life, form- 

 ing almost the entire soil on which we tread, it is difficult 

 to restrain the imagination from hazarding some conjec- 

 tures as to the causes by which such great efiects have been 

 produced." 



The deeper we descend into the strata of the Earth, the 

 higher do we ascend into the archosological history of past 

 ages of creation. We find successive stages marked by 

 varying forms of animal and vegetable life, and these gene- 

 rally differ more and more widely from existing species, as 

 we go farther downwards into the receptacles of the wreck 

 of more ancient creations. 



When we discover a constant and regular assemblage of 

 organic Remains, commencing with one series of strata, 

 and ending with another, which contains a different assem- 

 blage, we have herein the surest grounds whereon to esta- 

 blish those Divisions which are called geological formations, 

 and we find many such Divisions succeeding one another, 

 when we investigate the mineral deposites on the surface of 

 the Earth. The study of these Remains presents to the 

 Zoologist a large amount of extinct species and genera, 

 bearing important relations to existing forms of animals and 

 vegetables, and often supplying links that had hitherto ap- 

 peared deficient, in the great chain whereby all animated 



* Cuvier rapport sur le progr^s dcs sciences aatorciles, p. 119.. 



