the series of known fossil forms increased and the intrinsic 

 value of the paleontological evidence became clearer, the 

 doctrine of evolution finally claimed this field also as its 

 own. 



The nature of the case is such that the fossil record must 

 remain incomplete, perhaps forever. For not all the ani- 

 mals of former times possessed hard parts capable of re- 

 sisting the disintegrating forces of organic and inorganic 

 nature, the rocky tombs of those animals that were em- 

 bedded in the sands and silts have been crushed and rent 

 asunder by the very geological agencies that at first con- 

 structed them. More than half of the earth's surface is now 

 under water, while by no means all of the dry land is ac- 

 cessible. Only a few scratches have been made here and 

 there upon the earth's hard crust, so it is little wonder that 

 the testimony of the rocks is halting and imperfect. But 

 what there is, a rapidly growing body of cold, hard facts, 

 is in itself conclusive evidence of the reality of evolution. 

 Researches like those of Von Zittel, Cope, Hyatt, Marsh, 

 Osborn, and Scott, demonstrate that, when they appear at 

 all, the great groups or phyla of animals and their sub- 

 divisions succeed one another in that chronological order 

 which comparative anatomy and embryology have inde- 

 pendently shown is the order of their evolution. Then too 

 there are those fossil types that link together groups now 

 so widely separated, like Archaeopteryx, which is at once 

 a feathered reptile and a bird with reptilian tail and skull 

 and limbs. And there are the marvelously perfect series 

 of fossils like those which demonstrate the evolution of 

 modern horses and elephants; and finally, as the special 

 creationist Louis Agassiz himself showed, some fossil 

 series parallel very closely the embryonic record in modern 

 types. No field opens more invitingly than that of the 

 paleontologist. His tasks are to search the rocks every- 

 where for new fossil types to fill in the gaps of the lines of 



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