284 The Founders of Geology LECT. 



years Kamsay showed by a detailed examination of the 

 distribution of fossils in the sedimentary strata that 

 Darwin's suggestion must be accepted as an axiom in geo- 

 logical theory. Again, the great naturalist surmised that, 

 before the deposition of the oldest known fossiliferous 

 strata, there may have been antecedent periods, collectively 

 far longer than from the date of these strata up to the 

 present day, and that, during these vast, yet quite unknown, 

 periods, the world may have swarmed with living crea- 

 tures. But his contemporaries could only shrug their 

 shoulders anew, and wonder at the extravagant notions of 

 a biologist. But who nowadays is unwilling to grant the 

 possibility, nay probability, of Darwin's surmise ? Who 

 can look upon the earliest Cambrian fauna without the 

 strongest conviction that life must have existed on this 

 earth for countless ages before that comparatively well- 

 developed fauna came into existence ? For this expansion 

 of our geological vision, and for the flood of light which 

 has been thrown upon geological history by the theory 

 of evolution, we stand indebted to Charles Darwin. 



In the account which I have now placed before you of the 

 work of some of the more notable men who have created 

 the science of geology, one or two leading facts stand out 

 prominently before us. In the first place, even in the re- 

 stricted list of names which we have considered, it is 

 remarkable how varied have been the employments of 

 these men, and how comparatively few of them could be 

 called professional geologists. The majority of them have 

 been men engaged in other pursuits, who have devoted 

 their leisure to the cultivation of science. Guettard, 



