32 E VOL U TION A ND DOGMA . 



occurring at different heights and composed of peb- 

 bles rounded as by the motion of running water ; or 

 in what manner can such a cause account for the 

 petrification in the same places of various leaves, 

 sea-weeds and marine crabs?" 



Fracostoro, a contemporary of Da Vinci, followed 

 in the footsteps of the illustrious artist, and taught 

 that fossils were the exuviae of animals that former- 

 ly lived where their remains are now found. He 

 showed the futility of the opinion then prevalent 

 which attributed fossils to the action of the Noa- 

 chian Deluge, which, according to the ideas then en- 

 tertained, not only strewed the earth's surface with 

 the remains of the animals which were destroyed, 

 but also buried them at great depths on the highest 

 mountains. 



Clear and cogent arguments like those adduced 

 by Da Vinci and Fracostoro should have sufficed to 

 end all controversy regarding the true nature of 

 fossils, but unfortunately for the cause of science 

 the dispute was destined to last nearly three cen- 

 turies longer. All sorts of imaginary causes were 

 feigned to account for the petrified organic forms 

 everywhere abundant, and no theory was too fantas- 

 tical to attract supporters, provided only it was not 

 antagonistic to the notions of geogony and cos- 

 mogony then popularly received. 



. Thus, according to Agricola, fossils were the prod- 

 uct of a certain materia pinguis, or fatty matter, 

 set in fermentation by heat ; porous bodies, like 

 bones and shells, according to Mattioli, were petri- 

 fied by what he designated a "lapidifying juice," 



