58 THE HISTORY OF CREATION. 



was in one sense, yet in another it became to him the source 

 of a very serious error. For as he considered the charac- 

 teristic petrifactions of each individual group of strata 

 (which had been deposited during one main period of the 

 earth's history) to be entirely different from those of the 

 strata lying above or below, and as he erroneously believed 

 that one and the same species of animal was never found in 

 two succeeding groups of strata, he arrived at the false idea, 

 which was accepted as a law by most subsequent naturalists, 

 that a series of quite distinct periods of creation had 

 succeeded one another. Each period was supposed to have 

 had its special animal and vegetable world, each its peculiar 

 specific Fauna and Flora. 



Cuvier imagined that the whole history of the earth's 

 crust, since the time when living creatures had fiirst appeared 

 on the surface, must be divided into a number of perfectly 

 distinct periods, or divisions of time, and that the individual 

 periods must have been separated li'om one another by 

 peculiar revolutions of an unknown nature (cataclysms, or 

 catastrophes). Each revolution was followed by the utter 

 annihilation of the till then existing animals and plants, and 

 after its termination a completely new creation of organic 

 forms took place. A new world of animals and plants, 

 absolutely and specifically distinct from those of the preced- 

 ing historical periods, was called into existence at once, and 

 now again peopled the globe for thousands of years, till it 

 again perished suddenly in the crash of a new revolution. 



About the nature and causes of these revolutions, Cuvier 

 expressly said that no idea could be formed, and that the 

 present active forces in nature were not sufficient for their 

 explanation. Cuvier points out four active causes as the 



