SPECIES. 121 



day in mechanics. " It has changed mind into force." It is 

 certain that weak but continuous forces (everywhere, however, 

 the most powerful) have been able to play a grander part in the 

 history of our globe, than these disturbances which we are in 

 the habit of seeing everywhere. 



We consider that there ought to be an entire revolution 

 in the system of geological research; it ought to commence 

 at ancient times, and come down to the present day, not 

 vice versa; we ought, in fact, to substitute synthetic for ana- 

 lytical geology. After having carefully noticed contempo- 

 raneous phenomena, we should doubtless be in time able to 

 read simply the trace of a feeble revolution in the geolo- 

 gical past, accomplished under the government of the same 

 forces which are daily preparing new lands, new elevations, 

 new depressions, and a new organic world on the surface of 

 the globe, for the future. If it is probable that the atmo- 

 sphere has changed within certain limits, if the nature of the 

 waters has also been altered, at least all these geological phe- 

 nomena, these abysses, chains of mountains, and submerged 

 continents, can only be the result of the forces now at work 

 under our own eyes, the comparison of animals which for- 

 merly existed with those which exist at the present day, shows, 

 as we shall see farther on, that the conditions of life have not 

 sensibly changed on the surface of the globe since the forma- 

 tion of the rocks subjacent to the metamorphous rocks. 



We deny that the earth is actually passing through a period 

 of repose, and we do not believe that it has ever formerly been 

 more disturbed. Since the age of the first vestiges of the 

 organic life, which we find in the most ancient rocks, we think 

 that our planet has not ceased to move in a calm and con- 

 tinuous march of existence ; we think, in fact, that geological 

 phenomena of all sorts, which we hear of now-a-days, are the 

 exact history of the past, during which some volcanic pheno- 

 mena have also taken place, but in an entirely sporadic manner. 

 " The day is, perhaps, not very distant," said M. Lartet, at 

 the Institute,* in 1858, "when it will be proposed to strike 



* Comptes rendus des seances de I' Academic, February 22, 1858. 



