PALEOXTOLOGICAL DISCOVERY. 223 



mountains of Calabria, a considerable distance from the sea, a varie- 

 gated hard marble, in which many sea-shells but little changed were 

 heaped, forming one mass with the marble. 



With the beginning of the sixteenth century, a great impetus was 

 given to the investigation of organic fossils, especially in Italy, where 

 this study really began. The discovery of fossil shells, Avhich abound 

 in this region, now attracted gi'eat attention, and a fierce discussion soon 

 arose as to the true nature of these and other remains. The ideas of 

 Aristotle in regard to spontaneous generation, and especially his view 

 of the hidden forces of the earth, which he claimed had power to pro- 

 duce such remains, now for the first time were seriously questioned, 

 although it was not till nearly two centuries later that these doctrines 

 lost their dominant influence. 



Leonardo da Vinci, the renowned painter and philosopher, who was 

 born in 1452, strongly opposed the commonly accepted opinions as to 

 the origin of organized fossils. He claimed that the fossil shells under 

 discussion were what they seemed, and had once lived at the bottom 

 of the sea. " You tell me," he says, " that Xature 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." 

 Again, he says, " In what manner can such a cause account for the 

 petrifactions in the same place of various leaves, sea- weeds, and marine 

 crabs?" 



In 1517, excavations in the vicinity of Verona brought to light 

 many curious petrifactions, which led to much speculation as to their 

 nature and origin. Among tlie various authors who wrote on this sub- 

 ject was Fracastoro, who declared that the fossils once belonged to liv- 

 ing animals, which had lived and multiplied where found. He ridi- 

 culed the prevailing ideas that the plastic force of the ancients could 

 fashion stones into organic forms. Some writers claimed that these 

 shells had been left by Noah's flood, but against this idea Fracastoro 

 offered a mass of evidence, which would now seem conclusive, but 

 which then only aroused bitter hostility. That inundation, he said, 

 was too transient ; it consisted mainly of fresh water ; and, if it had 

 transported shells to great distances, must have scattered them over 

 the surface, not buried them in the interior of mountains. 



Conrad Gesner (151G-'65), whose history of animals has been con- 

 sidered the basis of modern zoology, published at Zurich, in 15G5, a 

 small but important work entitled " De omni rerum fossilium genere." 

 It contained a catalogue of the collection of fossils made by John 

 Kentmann. This is the oldest catalogue of fossils with which I am 

 acquainted. 



George Agricola (1494-1555) was, according to Cuvier, the first 

 minei-alogist who appeared after the revival of learning in Europe. 



