114 A CENTURY OF SCIENCE 



ner by Professor Marsh in his memorable presidential 

 address of 1879, History and Methods of PalaBontological 

 Discovery (18, 323, 1879), and by Karl von Zittel in his 

 most interesting book, History of Geology and Palaeon- 

 tology, 1901. In this discussion we shall largely follow 

 Marsh. 



The science of paleontology has passed through four 

 periods, the first of them the long Mystic period extend- 

 ing up to the beginning of the seventeenth century, when 

 the idea that fossils were once living things was only 

 rarely perceived. The second period was the Diluvial 

 period of the eighteenth century, when nearly everyone 

 regarded the fossils as remains of the Noachian deluge. 

 With the beginnings of the nineteenth century there 

 arose in western Europe the knowledge that fossils are 

 the " medals of creation " and that they have a chrono- 

 genetic significance ; also that life had been periodically 

 destroyed through world-wide convulsions in nature. 

 From about 1800 to 1860 was the time of the creationists 

 and catastrophists, which may be known as the Catas- 

 trophic period. The fourth period began in 1860 with 

 Darwin's Origin of Species. Since that time the theory 

 of evolution has pervaded all work in paleontology, and 

 accordingly this time may be known as the Evolutionary 

 period. 



Mystic Period. The Mystic period in paleontology 

 begins with the Greeks, five centuries before the present 

 era, and continues down to the beginning of the seven- 

 teenth century of our time. Some correctly saw that the 

 fossils were once living marine animals, and that the sea 

 had been where they now occur. Others interpreted fos- 

 sil mammal bones as those of human giants, the Titans, 

 but the Aristotelian view that they were of spontaneous 

 generation through the hidden forces of the earth domi- 

 nated all thought for about twenty centuries. 



In the sixteenth century canals were being dug in 

 Northern Italy, and the many fossils so revealed led to a 

 fierce discussion as to their actual nature. Leonardo da 

 Vinci (1452-1519) opposed the commonly accepted view 

 of their spontaneous generation and said that they were 

 the remains of once living animals and that the sea had 

 been where they occur. "You tell me," he said, "that 



