168 THEORY OP THE EARTH. 



in which they are imbedded ; the little resemblance 

 between these extraneous fossils of animals and 

 plants, as contained in the different basins of former 

 waters : All these form a series of phenomena 

 which imperiously demands the attention of phi- 

 losophers. 



This study is rendered interesting, by the va- 

 riety of productions of partial or general revolu- 

 tions which it affords, and by the abundance of the 

 different species which alternately offer themselves 

 to view ; it neither has that dull monotony which 

 attaches to the study of the primitive formations, 

 nor does it force us, like the latter, almost necessa- 

 rily into hypotheses. The facts with which it is 

 conversant are so prominent, so curious, and so 

 obvious, that they may suffice to occupy the most 

 ardent imagination; and the conclusions which 

 they afford from time to time, even to the most 

 cautious observer, have nothing vague or arbitrary 

 in their nature. Finally, by the careful investiga- 

 tion of these events, which approach, as it were, 

 to the history of our own race, we may hope to be 

 able to discover some traces of more ancient events 

 and their causes ; if, after so many abortive at- 

 tempts already made on the same subject, we may 

 yet flatter ourselves with that hope. 



These ideas have haunted, and I may even say, 

 have tormented me, during all my researches into 

 the fossil remains of bones, of which I now offer the 



