292 FOSSIL GEOLOGY (jNITED STATES. 



and massive mountains form, as it were, the great 

 charnel-houses of preceding generations, in wiiich 

 the petrified exuviae of extinct races of animals and 

 vegetables are piled into stupendous monuments 

 of the operations of life and death, during almost 

 immeasurable periods of past time. At the sight 

 of a spectacle," says Cuvier, "so imposing, so ter- 

 rible, as that of the wreck of animal life, forming 

 almost the entire soil on which we tread, it is diffi- 

 cult to restrain the imagination from hazarding 

 some conjectures as to the causes by which such 

 great effects have been produced." 



It is but recently, then, that fossil remains have 

 particularly engaged the attention of geologists. 

 The celebrated Tournefort, who lived in the 17th 

 century, believed that that they vvere stones that 

 grew, or vegetated from seeds. " How could the 

 Cornu Ammonis," says he, " which is constantly in 

 the figure of a volute, be formed without a seed 

 containing the same structure in the small as in the 

 larger forms ^ Who moulded it so artfully, and 

 where are the moulds!" Of the same opinion was 

 the philosopher John Locke, who states in his Ele- 

 ments of Natural Philosophy that " all stones are 

 real vegetables; that is, grow organically from prop- 

 er seeds, as well as plants." It is somewhat re- 

 markable, that even at the present time, notwith- 

 standing the progress made in geological and other 

 natural sciences, not only the uninformed and illit- 

 erate, but even men of intelligence, should still 

 hold to the same opinion, and maintain that the 

 vegetable or animal fossil, dug deep from the bow- 

 els of the earth, is either a fortuitous production, 

 or has grown to its present size from a seed or 

 grain ! 



Animal or vegetable substances found imbedded 

 in rocks are more or less impregnated with mineral 

 matter, and have been called petrifactions, from pe- 

 tros, a stone, and facio, to make. The process of 

 petrifaction consists in the infiltration of mineral 



