NATURAL HISTORY OF CREATION, 55 



found in what are now temperate regions ; he also states 

 that those of the higher rocks betoken, as we ascend, a 

 gradually diminishing temperature. 



We thus early begin to find proofs of the geiieral 

 uniformity of organic life over the surface of the earth, 

 at the time when each particular system of rocks was 

 formo<l. Species identical with the remains in the 

 Wenlock limestone occur in the corresponding class of 

 rocks in the Eifel, and partially in the Harz, Norway, 

 Kussia, and Brittany. The situations of the remains in 

 Russia are fifteen hundred miles' from the Wenlock beds ; 

 but at the distance of between six and seven thousand 

 from those — namely, in the vale of Mississippi — the 

 same species are discovered. Uniformity in animal life 

 over large geographical areas argues uniformity in the 

 conditions of animal life ; and hence arise some curious 

 inferences. Species, in the same low class of animals, 

 are now much more limited ; for instance, the Red Sea 

 gives different polypiaria, zoophytes, and shell-fish, from 

 the Mediterranean. It is the opinion of M. Brogniart, 

 that the uniformity which existed in the primeval times 

 can only be attributed to the temperature arising from 

 the internal heat, which had yet, as he supposes, been 

 sufiiciently great to overpower the ordinary meteoro- 

 logical influences, and spread a tropical clime all over the 

 fflobe. 



