120 DABWimAN'A. 



suddenly destroyed and renewed many times in suc- 

 cession, such a view could not be thought of. So the 

 equivalent view maintained by Agassiz, and formerly, 

 we believe, by D'Orbigny, that irrespectively of general 

 and sudden catastrophes, or any known adequate phys- 

 ical cause, there has been a total depopulation at the 

 close of each geological period or formation, say forty 

 or fifty times or more, followed by as many indepen- 

 dent great acts of creation, at which alone have species 

 been originated, and at each of which a vegetable and 

 an animal kingdom were produced entire and com- 

 plete, full-fiedged, as flourishing, as wide-spread, and 

 populous, as varied and mutually adapted from the 

 beginning as ever afterward — such a view, of course, 

 supersedes all material connection between succes- 

 sive species, and removes even the association and geo- 

 graphical range of species entirely out of the domain of 

 physical causes and of natural science. This is the ex- 

 treme opposite of Wallace's and Darwin's view, and is 

 quite as hypothetical. The nearly universal opinion, if 

 we rightly gather it, manifestly is, that the replacement 

 of the species of successive formations was not com- 

 plete and simultaneous, but partial and successive ; and 

 that along the course of each epoch some species prob- 

 ably were introduced, and some, doubtless, became ex- 

 tinct. If all since the tertiary belongs to our present 

 epoch, this is certainly true of it : if to two or more 

 epochs, then the hypothesis of a total change is not 

 true of them. 



Geology makes huge demands upon time ; and we 

 regret to find that it has exhausted om's — that what we 

 meant for the briefest and most general sketch of some 



