446 POPULAR SCIENCE MONTHLY 



tion, lusus naturae, as remains of creatures stranded by tidal waves or 

 cataclysms like the traditional flood, or again as the remains of animals 

 formed by a process of spontaneous generation in the depths of the 

 earth that had failed to reach the surface. It was Leonardo da Vinci 

 of the fifteenth century who, anticipating the naturalists of later times, 

 believed these vestiges are what common-sense says they are — simply 

 relics of creatures that lived when the earth was younger. Cuvier was 

 in a true sense the founder of paleontology ; though a special creationist, 

 he recognized that beneath their differences there were fundamental 

 likenesses between recent and extinct animals. He assumed that cata- 

 clysms had closed the several geologic epochs whereupon new series 

 of animals and plants were created upon the same general working-plans 

 employed in earlier ages; thus he combined the idea of change in 

 geologic time with a belief in supernatural creation. When, however, 

 Lyell led geologists and others to abandon the cataclysmic hypothesis 

 in favor of the doctrine of uniformitarianism, when 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 animals of former times 

 possessed hard parts capable of resisting the disintegrating forces of 

 organic and inorganic nature, the rocky tombs of those animals that 

 were embedded in the sands and silts have been crushed and rent 

 asunder by the very geological agencies that at first constructed them. 

 More than half of the earth's surface is now under water, while by no 

 means all of the dry land is accessible. 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 conclu- 

 sive evidence of the reality of evolution. Eesearches 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 com- 

 parative anatomy and embryology have independently shown is the 

 order of their evolution. Then, too, there are those fossil types that 

 link together groups now so widely separated, like Archeopteryx, 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 everywhere for new fossil types to 



