PRELUDE TO DESCRIPTIVE GEOLOGY. 539 



of strata, the constancy of their organic contents, 

 their correspondence in different countries, and 

 such great general relations of the materials and 

 features of the earth as have been discovered up to 

 the present time. Without attempting to assign to 

 every important advance its author, I shall briefly 

 exemplify each of the modes of contributing to 

 descriptive geology which I have just enumerated. 



The study of organic fossils was first pursued 

 with connexion and system in Italy. The hills 

 which on each side skirt the mountain-range of the 

 Apennines are singularly rich in remains of marine 

 animals. When these remarkable objects drew the 

 attention of thoughtful men, controversies soon 

 arose whether they really were the remains of living 

 creatures, or the productions of some capricious 

 or mysterious power by which the forms of such 

 creatures were mimicked ; and again, if the shells 

 were really the spoils of the sea, whether they had 

 been carried to the hills by the deluge of which 

 the Scripture speaks, or whether they indicated 

 revolutions of the earth of a different kind. The 

 earlier works which contain the descriptions of the 

 phenomena have, in almost all instances, by far the 

 greater part of their pages occupied with these spe- 

 culations; indeed, the facts could not be studied 

 without leading to such inferences, and would not 

 have been collected but for the interest which such 

 reasonings possessed. As one of the first persons 

 who applied a sound and vigorous intellect to these 



