47 



Finally, even the hard parts of animals, and especially those of 

 land animals, are, and always have been, subject to rapid decom 

 position when exposed to atmospheric influence, although they may 

 be preserved indefinitely when buried beyond the reach of such 

 influence. It is this rapid destruction of the remains of land ani 

 mals which is largely the cause that their geological history is so 

 incomplete as compared with that of marine life. 



An illustration showing how rapidly traces of important land faunas 

 may have disappeared in former geological times is furnished by 

 the living bison, or buffalo, of North America. Perhaps the earth 

 has never witnessed such enormous numbers of any one species of 

 large animals occupying such a broad continental area, as in the 

 case of the buffalo. Its range once extended from the vicinity of 

 the Atlantic to the mountains which border the Pacific coast, and 

 from Mexico to near the Arctic circle, and its numbers were so 

 great, even within the last twenty-five years, as to impede travel 

 across the great plains of the West. So rapidly is this animal now 

 passing away that it has disappeared from all but a fraction of its 

 former range ; and I venture the prediction that there are persons 

 now living who will witness its entire extinction in its free state. 

 It is true that relentless man has brought about this wholesale de 

 struction, but that does not alter the force of the application I wish 

 to make of the fact that the buffalo is passing away and leaving, by 

 natural means, hardly any trace of its former existence. In all that 

 region where it has lived so many centuries in abundance, traces of 

 even its bones and teeth are rarely found. 



Few places in all its former wide range have furnished the con 

 ditions necessary for the preservation, by sedimentary interment, 

 of the bones of the buffalo beyond the reach of atmospheric influ 

 ence ; and the result has been that they have generally disappeared 

 by decomposition as completely as the flesh has done. It is doubt 

 less in a similar manner that the other great terrestrial faunas have 

 been destroyed in former geological periods, for the remains of ter 

 restrial animals have not usually fallen in conditions at all favora- 



