SPECIES. 8 



cession of these rocks with regard to one another. But it leaves 

 us in absolute ignorance of all which has passed between the 

 deposit of one stratum and the deposit of that which we meet 

 with above it; in this unknown time all may take place, 

 ten series of rocks may have been placed upon it, and then 

 have been so well mingled together that we cannot discover 

 their individual trace. Who will tell us about the continents 

 engulphed by the sea ; has it not already ground up under its 

 waves those memorials of ancient days, which would be so use- 

 ful to us as a means of reconstructing the history of man? 

 Geology is a gigantic inscription lacerated for ever : each age 

 will decipher some fragment, but we shall never be able to 

 read it in its perfect state. 



Besides its great advantages, palseontological inquiry has 

 its great inconveniences. Its advantages are the studying of 

 animal forms which are fixed for ever, and not seeing the 

 field of such studies continually increasing on our view. The 

 limit of its inquiries is the origin of the alluvium; all the facts 

 which we are thereby called upon to study are within this 

 boundary. Palaeontology alone, among the sciences of the 

 present day, knows the extent of its domain. 



But palaeontology, proceeding step by step, by blows of the 

 pickaxe in an otherwise inaccessible mass, is composed of two 

 orders of facts, which must be distinguished one from the 

 other, resting either on affirmative evidence (the existence 

 of organic remains in a rock) or' on negative evidence (the 

 absence of organic remains in a rock) . Human palaeontology 

 itself has its own inconveniences. A bone or a skull of a man 

 are things which are well known ; they have not that strange 

 appearance in the eyes* of the crowd which makes them take 

 ammonites for petrified serpents, hamites* for leeches, radiated 

 animals for stars ; when we dig up some singular bone, some 

 carapace of a lizard, a fish, or of some unknown animal, we 

 pick it up, and take great care of it. But if it is a man's 

 head, it is generally replaced religiously in the earth, and these 

 remains are for ever lost to the scientific world. 



* [Hamites, a genus of extinct Cephalopods, found in the greensand forma- 

 tion in England. EDITOR.] 



K 2 



