INTRODUCTION 21 



douter qu'apres avoir occupe les parties septentrionales de la Russie et de la 

 Siberie . . . oil Von a trouve leurs depouiiles en grande quafitite, ils n'aient 

 ensuite gagne les terres mains septentrionales . . . en sorte qu'd mesure que 

 les terres du Nord se refroidissoient, ces animaux cherchoient des terres plus 

 chaudes. . . . (Tome V, p. 172, Supplement.) This sagacious naturalist 

 also pointed out that these monuments of the extinct life of the earlier 

 ages of the world were understandable by comparison of their structure 

 with that of living animals of related type; such comparison, he ol)served, 

 demonstrates the existence in times past of species different from those 

 actuall}^ existing but closely related (Tome V, p. 154, Mineraux). 



Cuvier observes that fossils, which have given birth to the theory of the 

 earth, have also furnished it with its principal lights, the only ones which 

 have been generally recognized down to the present period. He extends 

 Buffon's ideas, and gives new and beautiful theoretical illustrations of the 

 possible effects of continental elevation and depression, which we may 

 paraphrase ^\dth slight modifications of his own language. 



Let us suppose, Cuvier remarks in his Discours (Paris, 1826, pp. 64-65), 

 that a great invasion of the sea covers with a mass of sand or other deposit 

 the continent of Australia; it would bury the carcasses of the kangaroos, 

 wombats, dasyures, bandicoots, flying phalangers, as well as of the duck- 

 bills [Ornithorhynchus] and spiny anteaters [Echidna]. It would entirely 

 destroy these species of animals because none of them exist in any other 

 country. Suppose, further, that the same convulsion of nature were to 

 leave dry the numerous small straits which separate Australia from the 

 continent of Asia; it would open the way for the entrance into Australia 

 of the elephant, rhinoceros, buffalo, horse, camel, tiger, and all other Asiatic 

 quadrupeds, which would come to people this continent in which they 

 were before unkno\\Ti. If, however, a naturalist studying these living ani- 

 mals were to lay open the soil on which they moved he would find the re- - 

 mains of the buried ancient fauna of marsupials, etc. What Australia 

 would become were such a hypothetical invasion realized, Europe, Siberia, 

 and a great portion of America are to-day, and it may some day be dis- 

 covered in the examination of these countries, and even of Australia itself, 

 that they have all experienced similar revolutions. To carry the above 

 hypothesis still further, Cuvier concludes, after the Asiatic animals have 

 migrated into Australia let us imagine that a second revolution destroyed 

 Asia, the original home of these animals: the naturalist who discovered 

 their second country would be as much embarrassed to find whence they 

 came as we can now be to discover the origin of those animals which are 

 found in our o^^^l countries. 



Despite these sagacious views, Cuvier was an exponent of the cata- 

 clysmal rather than the unif ormitarian school of transformation, that is, 

 he believed in violent changes in past times rather than in the slow changes 

 such as we observe to-day. Experience has proved that he was somewhat 



