zoologists generally feel that used with due caution the law 

 has a high value for the student of evolution, and they real- 

 ize that embryology is perhaps more significant in other re- 

 spects than in showing exactly how in past times any given 

 species has evolved. The present tasks in this department, 

 now so thoroughly investigated, are to distinguish between 

 the false and the true portions of the record, between the 

 new and the old, and to ascertain the physiology of devel- 

 opment, in order to gain a more complete knowledge of 

 racial history and of the dynamics of organic nature. 



The study of the fossil remains of animal organisms, or 

 paleontology, is the fourth division of structural zoology, 

 which as an independent branch dates back to the time of 

 Cuvier, scarcely a hundred years ago. Vestiges of creation 

 were indeed known long before that time, but they were 

 variously regarded as freaks of geological formation, lusus 

 naturce, as remains of creatures stranded by tidal waves or 

 cataclysms like the traditional flood, or again as the re- 

 mains of animals formed by a process of spontaneous gen- 

 eration 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, be- 

 lieved 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 pale- 

 ontology; 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 be- 

 lief in supernatural creation. When, however, Lyell led 

 geologists and others to abandon the cataclysmic hypo- 

 thesis in favor of the doctrine of uniformitarianism, when 



12 



