2 FOSSIL MAMMALIA. 



prevent us from entering very deeply into the purely geolo- 

 gical portion of the subject, or, in fact, of considering it at all, 

 except in relation to its connection with the organic fossils. 



An inspection of the various strata in vi^hich fossil remains 

 have teen deposited, serves to prove that, in general, a con- 

 stant order has been observed in their formation. 



The sea, by which the entire earth appears to have been 

 covered, having rested in certain situations a sufficient length 

 of time to collect particular substances, and sustain the life of 

 certain genera and species of animals, has been afterwards 

 replaced by another sea, which has collected other substances, 

 and nourished other animals. 



It may be believed that the primitive strata, which contain 

 no organic remains, had all of them one contemporaneous 

 origin. But, with respect to the strata which cover them, the 

 study of fossil osteology has clearly proved that they were 

 formed at different eras of time, during each of which animals 

 existed distinct from those which lived in other eras, and dis- 

 tinct from almost all the known species which exist at the 

 present day. It is true, that those causes to which the produc- 

 tion of mountains is owing, have, in the countries which are 

 intersected by primitive chains, or which border on them, dis- 

 turbed the original established order of the strata. But, in 

 level countries, it is perfectly obvious that they have been 

 formed by a long and tranquil sojournment of the waters, in 

 the same manner as are formed, at the present day, those 

 depositions which cover the bottom of the seas. 



Vegetable and animal remains are sometimes found at a 

 depth of three or four thousand feet, and even below the sea, 

 as in the instance of the coal-pits of TV hitehaven. In all parts 

 of the world, marine productions are to be found in a fossil 

 state. They are found at very considerable degrees of eleva- 

 tion, on mountains far remote from the neighbourhood of any 

 sea. So numerous, indeed, are they in certain places, that 

 they constitute, to a very great extent, the aggregate of 



