Results of Geological Observations. 5 



respecting the origin of earlier races of animals and plants. 

 It is satisfactorily ascertained at present, that there have been 

 many distinct successive periods, during each«of which large 

 numbers of animals and plants have been introduced upon 

 the surface of our globe, to live and multiply for a time, then 

 to disappear and be replaced by other kinds. Of such dis- 

 tinct periods, such successive creations, w^e now know at least 

 about a dozen, and there are ample indications that the in- 

 habitants of our globe have been successively changed at more 

 epochs than are yet fully ascertained. But whether the num- 

 ber of these distinct successive creations be twelve or twenty, 

 the fact stands in full light and evidence, that animals and 

 plants which lived during the first period disappeared, either 

 gradually or successively, to make room for others, and this 

 at often -repeated intervals ; and that the existence of animals 

 and plants which live now is of but recent origin, is equally 

 well ascertained. 



There is another series of phenomena, not less satisfac- 

 torily established, which go to shew that the extent of dry 

 land rising above the surface of the ocean has neither been 

 equally extensive at all times, nor has it had the same out- 

 line at all periods. On the contrary, we know that, early in 

 the history of our globe, there has been a period, when but 

 few low groups of islands existed above the surface of the 

 ocean, which, through successive elevation and depression, 

 have gradually enlarged and modified the extent and form of 

 the mainland. 



Again, in examining the remains of organized beings pre- 

 served in the different strata constituting the solid crust of 

 our globe, we find that at each period, animals and plants 

 were distributed in the ocean and over the mainland in a 

 particular manner, characteristic of every great epoch. A 

 closer uniformity in their distribution is found in the earlier 

 deposits, so much so that the oldest fossils discovered in the 

 southern extremity of Africa, on the eastern and southern 

 chores of New Holland, and in Van Diemen's Land, in North 

 America, or in various parts of Europe, are almost identical, 

 or at least so nearly related, that they resemble each other 

 much more than the animals and plants which at present 



