318 GEOLOGY. 



the animal kingdom, have been produced by the 

 changes which accompanied the successive deposi- 

 tions of the strata. According to this view of the 

 matter, the animals and vegetables with which the 

 earth is at present covered, could not have lived at 

 the period when the transition rocks were forming. 

 A variety of changes have taken place in succession, 

 giving to the earth its present character, and fitting 

 it for the residence of its present inhabitants, which 

 the progress of the same system may again render 

 unfit. 



Agreement of Fossils with their Strata. 



Peculiar fossils are found to characterize particular 

 strata, so that the strata may in many respects be 

 predicated from the organized fossils found there. 



If a collection of fossils from the chalk of Flambo- 

 rough Head, from the cliffs of Dover, from Paris, or 

 from Poland, be examined, eight or nine out of ten 

 species will be found the same. The same echinites 

 will be found associated with the same shells, and 

 nearlv half of these will be found to belong to divi- 

 sions of that family (echinites) unknown in a recent 

 state, and indeed in any other fossil bed except 

 chalk. 



If fossils found in the carboniferous limestone be 

 inspected, from whatever locality, they will be found 

 to agree with each other in the same manner, that is 

 to say, the same coral, the same encrinites, terebra- 

 tulae, spiriferae, &c. will be discovered. 



But, if, on the other hand, the collection from the 

 chalk be compared with that from the mountain lime, 

 not one instance of specific agreement will be per- 

 ceived, which proves that they are not irregularly or 

 accidentally distributed, each formation containing an 

 association of species, peculiar in many instances to 

 itself. 



