18 THE TRANSFORMATIONS OF THE ANIMAL WORLD 



species of fossil invertebrates, arranged in the 

 chronological order of their appearance during the 

 twenty- seven successive stages which, according to 

 the author, constitute the sedimentary crust of 

 the earth. From the whole of this immense work 

 there breathed into the minds of nearly all the 

 palaeontologists of that epoch and among them 

 may be cited the illustrious names of Agassiz and 

 d'Archiac the most striking confirmation of the 

 theories of Cuvier on the fixity of species and the 

 almost complete renewal of successive faunas. 

 Alcide d'Orbigny again proclaimed himself, in 1849, 

 in his Cours elementaire de Paleontologie Strati- 

 graphique, the convinced champion of Cuvier's 

 ideas by pushing them far beyond the limits acknow- 

 ledged by the master. The theories of d'Orbigny 

 may be summed up as follows : From the first to 

 the latest epoch of the animated world we see 

 appear at all points of it, at one and the same time, 

 a great multitude of different species belonging to 

 all branches of the animal kingdom, of which there 

 are no signs in the preceding periods. 



" The first creation shows itself in the Silurian 

 stage. After its annihilation through some geological 

 cause or other, a second creation took place a con- 

 siderable time after in the Devonian stage, and, 

 twenty-seven times in succession, distinct creations 

 have come to repeople the whole earth with 

 its plants and animals after each of the geo- 

 logical disturbances wliich destroyed everything in 

 living nature. Such is the fact, certain but incom- 

 prehensible, which we confine ourselves to stating, 

 without endeavouring to solve the superhuman 



