138 Report of the State Geologist. 



remains. Cuvier had discovered (1812) part of a skeleton, the 

 jawbone of which seemed to him very analogous to that of a 

 marsupial. By . virtue of the principle of the correlation of 

 forms which he had established, he affirmed that bones of a 

 marsupial animal must be found . in the deposit. He caused the 

 rock to be excavated in the presence of a large number of per- 

 sons, in order to disengage the posterior part of the body, and 

 his hypothesis was verified to the great admiration of the contem- 

 porary scientific world. 



A fact not less important in the history of Palaeontology was 

 the determining, by Cuvier, of the character of a jawbone found 

 in the Bathonian of Stonesfield. He demonstrated in 1818 that 

 this remnant appertaining to the genus Thylacotherium belonged 

 to a mammifer of the group of marsupials. This discovery over- 

 threw the theory of the naturalists of that epoch, who were un- 

 willing to believe that a mammifer could be of such ancient date. 

 It was not until thirty years later that marsupial remains were 

 found in the Triassic deposits. 



Cuvier devoted himself before all else to establishing the 

 true zoologic nature of fossil animals, especially the mam- 

 malia. He proved definitely that before the existence of the 

 present fauna, there existed rhany successions of diverse faunas. 

 The disappearance of pre-existent forms, and their replacement 

 by new ones was believed to have taken place abruptly, caused by 

 cataclysms which affected the entire surface of the earth. For 

 the hypothesis of a single creation, Cuvier thus substituted that of 

 several creations 'following each other at longer or shorter inter- 

 vals. It is unnecessary to add that Cuvier was a firm partisan 

 of the theory of the immutability of species. Incorrect though 

 it was, still the theory of cataclysms was the one that would 

 most naturally present itself to the mind to explain the profound 

 diversities existing between the faunas of successive layers, at 

 least in the regions explored previous to the epoch we are now 

 considering. 



The influence of Cuvier was felt during his lifetime, and even 

 his errors proved a point of departure for a progressive move- 

 ment. Since his time fossils have been studied with a deeper 

 interest, as an idea can now be formed of the living creatures 

 they represent, and attempts be made toward reconstructions, 



