BOOK VIII 

 CHAPTER XXVIII 



THE APPEARANCE OF LIFE ON THE GLOBE 



The geological problem of the beginnings of life The Silurian world 

 The primordial fauna of Barrande The Cambrian world The 

 pre-Cambrian fossils of Brittany and of the Rocky Mountains 

 The crystallophylliau earths and the metamorphism of the old 

 sediments. 



ONE last and most burning question presents itself 

 to us at the end of this sketch of the transformations 

 of the animal world on the surface of the terrestrial 

 globe. It is that of the very origins, or, more 

 exactly, of the first beginnings of life on the earth. 

 There can be no question here of considering the 

 problem from its biological side. How did the 

 mysterious flame which we call life come, at a given 

 moment in the geological evolution of our planet, 

 to animate inert organic matter and transform these 

 compounds of a little carbon, water, and nitrogen 

 into a living cell, or even into the first granule of 

 irritable and mobile protoplasm ? Here is, no 

 doubt, a fundamental question, but one entirely 

 beyond the scope of a geologist and palaeontologist. 

 It may even be fearlessly added that this redoubt- 

 able problem has till now defied the efforts of every 

 biologist, notwithstanding some bold attempts at 



