THEORY OF THE EARTH. 51 



ment, they have almost always neglected to in- 

 vestigate the general laws affecting the geologi- 

 cal position of organic remains, or their connec- 

 tion with the strata. 



Importance of Fossil Remains in Geology. 



And yet, the idea of such an investigation was 

 very natural ; for it is abundantly ohvious, that it 

 is to these fossil remains alone that we owe even the 

 commencement of a theory of the earth, and^that, 

 without them, we should perhaps never have even 

 suspected that there had existed any successive 

 epochs, and a series of different operations, in the 

 formation of the globe. By them alone we are, in 

 fact, enabled to ascertain, that the globe has not al- 

 ways had the same external crust ; because, we 

 are thoroughly assured, that the plants and 

 animals must have lived at the surface before 

 they had thus come to be buried deep beneath it. 

 It is only by analogy that we have been enabled 

 to extend to the primitive formations, the con- 

 clusion which is furnished directly for the secon- 

 dary by the organic remains which they contain ; 

 and if there had only existed formations in which 

 no fossil remains were inclosed, it could never 

 have been shewn that these formations had not 

 all been of simultaneous origin. 



It is also by means of the organic remains, 

 slight as is the knowledge we have hitherto ac- 



