318 ON THE DEPOSITS CALLED TERTIARY 



of quadrupeds in such deposits, or the alternations of 

 these and their loose alluvia with solid rocks. I have 

 shown, in another place, that crowds of skeletons of 

 land animals are sometimes deposited in the sea 

 itself, and, in a former chapter, how rocks are pro- 

 duced from these loose materials. And thus may we 

 dismiss, through a simple reasoning from the most 

 common facts, all the .wonders which have been 

 attached to these basins, with their deposits and their 

 contents, be those what they may. 



Thus far, all is simple. There are tertiary strata, 

 in basins, either of fresh or of salt water, in both cases 

 Lacustral, in both containing terrene quadrupeds, in 

 the latter case containing marine, and fresh water, or 

 terrene, remains intermixed, and, in both, remaining 

 in the very places where they were formed; remaining 

 also undisturbed, and as easily assignable by any 

 geologist deserving of this name, as the thousand 

 more limited deposits of recently extinguished lakes. 

 It were well if geological investigations were always 

 as easy. That the deposits of Oeningen should have 

 been so long mistaken, is a proof of the very scanty 

 portion of observation and of reasoning which geolo- 

 gists have contrived to possess and apply to their 

 science. 



Thus we have a division of tertiary strata which 

 will be single, if we rest it on the fact that it is in 

 situ, or remains where it was formed ; while if the 

 quality of the water be held a necessary ground of 

 further division, we must make two classes. I am, 

 myself, inclined to consider it as one class out of 

 the two into which I should divide the proper tertiary 

 strata. Of the other class, the history and the theory 

 both, are far more intricate; though I hope to show 

 that the one which I shall propose is the true one. 



