Charles Schuchert — Historical Geology, 1818-1918. 97 



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. |f 



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 

 Nature and the influence of the stars have formed these 

 shells in the mountains ; then show me a place in the 

 mountains where the stars at the present day make shelly 

 forms of different ages, and of different species in the 

 same place." However, nothing came of his teachings 

 and those of his countryman Fracastorio (1483-1553), 

 who further ridiculed the idea that they were the 

 remains of the deluge. The first mineralogist, Agricola, 

 described them as minerals — f ossilia — and said that they 

 arose in the ground from fatty matter set in fermenta- 

 tion by heat. Others said that they were freaks of 

 nature. Martin Lister (1638-1711) figured fossils side 

 by side with living shells to show that they were extinct 

 forms of life. In the seventeenth century, and especially 

 in Italy and Germany, many books were published on 

 fossils, some with illustrations so accurate that the 

 species can- be recognized to-day. Finally, toward 

 the close of this century the influence of Aristotle and the 

 scholastic tendency to disputation came more or less to 

 an end. Fossils were already to many naturalists once 

 living plants and animals. Marsh states: "The many 



Am. Jour. Sci.— Fourth Series, Vol. XLVI, No. 271.— July, 1918. 

 4 



