138 ON THE REVOLUTIONS OF 



nature lias enveloped this earth. Geology has detected it hy com- 

 bining the lights of mineralogy with those furnished by the sciences 

 of organic structure and existence ; an order so new and pregnant 

 with fact, that it has only been acquired since the actual proofs 

 offered to observation have been preferred to fantastic systems, and 

 contradictory conjectures on the primary origin of the globe, and all 

 those phenomena, which in nowise resembling those to which we are 

 accumstomed, could neither detect therein, to throw a light on the facts, 

 materials to produce it, or a touchstone to try and prove. Some years 

 since, the majority of geologists might be compared to historians who 

 were only interested in the history of Fiance with regard to what 

 passed amongst the Gauls before Julius Cyesar ; but yet these histo- 

 rians, in composing their romances, availed themselves of their ac- 

 quaintance with subsequent facts, while the geologists alluded to en- 

 tirely neglected the posterior occurrences which alone could cast any 

 light on the obscurity of former times. 



In conclusion, it only remains for me to present the result of my 

 individual researches, or in other words the summary of my great 

 work. I shall enumerate the animals that I have discovered, in an 

 order the reverse of that which I have followed in enumerating the 

 formations. By going deeper and deeper into the series of layers, I 

 got more and more remote as to the epochs of time. I shall now 

 commence with the most ancient formations, and mention the animals 

 found in them, and passing from epoch to epoch, point out those 

 which successively present themselves, in proportion as they approach 

 more nearly to the present age. 



Enumeration of the Fossil Animals detected by the Author. 



We have seen that zoophytes, mollusca, and certain Crustacea begin 

 to appear in the transition formations ; there may be even at that 

 period bones and skeletons of fishes ; but they are at a very consider- 

 able distance from the epoch in which we discover the remains of ani- 

 mals which live on the earth and breathe the air of nature. 



The vast beds of coal, and the trunks of palms and ferns, of which 

 they retain the impressions, although already evidencing dry lands, 

 and a vegetable thereon, do not yet show any bones of quadrupeds, 

 nor even of oviparous quadrupeds. 



It is only a little above, in the coppery bituminous slates, that we 

 discover the first traces of them ; and what is very remarkable, the 

 first quadrupeds are reptiles of the lizard tribe, very much like the large 

 monitors now existing in the torrid zone. Several individuals of this 



