100 Observations Concerning Fossil Organic Remains. 



can be formed at the same time and in the same pkice. Ge- 

 ology has made us acquainted with a series of formations of 

 quite a different nature, and whose characters are sufficient- 

 ly dislinct to prove to us that they belong to epochs decided- 

 ly dilierent. 



The mica-slate, the alpine limestone, the sandstones with 

 lignite are rocks whose nature is very different, and I cannot 

 believe that any one would wish to defend the idea that these 

 rocks could have been formed in the same moment and in 

 the same place, whilst every thing announces to us, that they 

 belong not only to epochs but to periods widely remote. 

 Truly, by admitting such a doctrine, we run the hazard of 

 confounding geological phenomena in such a manner, as, 

 that finally we shall lose the path which alone can conduct 

 us to the true knowledge of things. 



M. Brongniart informs us, that whatever has taken place 

 upon the surface of the earth, belongs to the same epoch or 

 period. I cannot allow, it belongs to the same period with 

 that in which the earth was, when it recovered itself after the 

 last great catastrophe : a period continues, but this period is 

 divisible into many epochs which are truly distinct from each 

 other. It is true that the organic remains contained in the 

 newer formations, possess all those characters which are 

 common to the tribes now occupying the face of the earth; 

 but it does not follow from thence, that since the organic re- 

 mains possess a similar character, that different strata ought 

 to be regarded as belonging to the same epoch of formation. 

 I allow they may belong to the same /?rrior/, but not to the 

 same epoch. Many active volcanos, belong to the period 

 in which we live, but not to the epoch', and that they do not, 

 is obvious from their ejected matters. For it is ascertained 

 that lavas of the same volcanos, differ at diflTerent epochs ; 

 and we can easily conceive that volcanic products, evolved 

 during a period of thousands of years would differ from each 

 other, and that they would evince by this diflference, the dis- 

 tance of the epochs which separate them. The differences, 

 then among volcanic products, are so many proofs that they 

 were formed at different epochs. Organic remains may 

 possess a common character, as well as rocks which are the 

 result of different formations and epochs widely remote. 

 Since the period, successive to the last great catastrophe, the 

 earth has certainly undergone partial derangements, but which 

 have not interfered with the existence of genera of plants and 



