430 ON THE GEOLOGICAL RELATIONS 



New Holland at present would produce this very effect. 

 An entire collection of animals, distinct also from 

 every other, would he extirpated from the earth. 



But it would he wrong to apply such causes or spe- 

 culations too widely. Many animals are now he- 

 coming more concentrated, as they are also diminishing 

 in numbers, chiefly from the progress of man and the 

 changes of the earth which follow this, in change or 

 limitation of food, if possibly also, in part, from their 

 mutual interferences, from epizootic diseases, from 

 changes of climate, the destruction of forests, and 

 perhaps other causes, unknown to us. And thus, 

 probably, without any geological catastrophes, have 

 the numerous extinct animals of particular regions, 

 such as the elephants of Germany and Siberia, and 

 our own lost quadrupeds, disappeared. Hereafter, I 

 shall have occasion to recur in some measure to this 

 subject. 



It is more easily to be understood why there should 

 be no correspondence between existing and fossil 

 plants. The latter belong, if antient, to the Coal 

 Series and the lias only; and each of these has under- 

 gone revolutions which must have destroyed all 

 germs. An ocean might have protected what the 

 earth could not. And accordingly, if analogies have 

 been pointed out, that is all: though it is plain that 

 genera at least could not be thus traced, since the 

 characteristic marks are not preserved. As to the 

 tertiary strata, identities are probable, and, in the al- 

 luvia confounded with these, certain. 



I may conclude with this general remark, that the 

 correspondence of fossil genera or species with living 

 ones is scarcely a question of Geology. The revo- 

 lutions of the earth are proved by safer evidence. 

 There may have been new creations following revo- 



