LYELLS GEOLOGICAL DOCTRINES. 1 27 



development, and effected this reform in a manner similar to 

 that in which, thirty years later, Darwin in his work reformed 

 the science of Biology. Lyell's great treatise, which radically 

 destroyed Cuvier's hypothesis of creation, appeared in the 

 same year in which Cuvier celebrated his triumph over the 

 nature-philosophy, and established his supremacy in the 

 domain of morphology for the following thirty years. 

 Whilst Cuvier, by his artificial hypothesis of creation and 

 his theory of catastrophes connected with it, directly ob- 

 structed the path of the theory of natural development, 

 and cut off all chance of a natural explanation, Lyell once 

 more opened a free road, and brought forward convincing 

 geological evidence to show that Cuvier's dualistic concep- 

 tions were as unfounded as they were superfluous. He 

 demonstrated that those changes of the earth's surface, 

 which are still taking place before our eyes, are perfectly 

 sufficient to explain everything we know of the development 

 of the earth's crust in general, and that it is superfluous and 

 useless to seek for mysterious causes in inexplicable revolu- 

 tions. He showed that we need only have recourse to the 

 hypothesis of exceedingly long periods of time in order to 

 explain the formation of the crust of the earth in the simplest 

 and most natural manner by means of the very same causes 

 which are still active. Many geologists had previously 

 imagined that the highest chains of mountains which rise on 

 the surface of the earth could owe their origin only to 

 enormous revolutions transforming a great part of the earth's 

 surface, especially to colossal volcanic eruptions. Such 

 chains of mountains as those of the Alps or the Cordilleras 

 were believed to have arisen direct from the fiery fluid of the 

 interior of the earth, through an enormous chasm in the 



