EVIDENCE OF FOSSIL RE^UINS 75 



results of the other in order to accomphsh its own dis- 

 tinct purposes. It must be evident to every one that it 

 is impossible to understand the meaning of fossils and 

 the place of the testimony of the rocks in the doctrine 

 of evolution without knowing much about the geolopical 

 history of the earth and the influcMices at work in the 

 past. For these reasons palaeontology dilTers somewhat 

 from the other divisions of zoology where direct observa- 

 tion gives the materials for arrangement and study; 

 in this case the individual data, that is, the fossil frag- 

 ments themselves, can be made available only through a 

 knowledge of their exact situations, of the reasons for 

 their occurrence in particular places in the rock series 

 and of the way rocks themselves are constructed and 

 worked over by natural agencies. Our task is there- 

 fore twofold : certain physical matters of a geological 

 nature must first be investigated before the biological 

 facts can be described. 



No doubt most people feel justified in believing that 

 the whole doctrine of evolution must stand or fall 

 according to the cogency of the pahrontological evi- 

 dences. Plain common sense says that the owners of 

 shelly or bony fragments found in the dcH^ply-laid 

 strata of the earth must have lived countless years 

 ago, and if the evolutionist asserts that ]>rimitive or- 

 ganic forms of ancient times have produced changed 

 descendants of later times, it would seem that f()>-il 

 evidence would be supremely and overwh(^lniingly 

 important. It is true, of course, that this evidence is 

 pecuharly significant, because in some ways it is more 

 direct than that of the other categories already outlined. 

 But it must not be forgotten that the doctrine is already 



