CHAPTER FOURTEENTH. 



GEOLOGICAL SUCCESSION OF ANIMALS ; OR, THEIR DIS- 

 TRIBUTION IN TIME. 



SECTION I. 



STRTJCTUEE OF THE EAETH'S CEUST. 



642. THE records of the Bible, as well as human tra- 

 dition, teach us that man and the animals associated with 

 him were created by the word of God ; " The Lord made 

 Heaven and earth, the sea, and all that in them is ;" and 

 this truth is confirmed by the revelations of science, which 

 unequivocally indicate the direct interventions of creative 

 power. 



643. But man and the animals which now surround 

 him are not the only kinds which have had a being. The 

 surface of our planet, anterior to their appearance, was not a 

 desert. There are, scattered through the crust of the earth, 

 numerous animal and vegetable remains, which show that 

 the earth had been repeatedly supplied with, and long in- 

 habited by animals and plants altogether different from those 

 now living. 



644. In general, their hard parts are the only relics of 

 them which have been preserved, such as the skeleton and 

 teeth of vertebrata ; the shells of mollusca and radiata ; 

 the shields of crustaceans, and sometimes the wing-cases 

 of insects. Most frequently they have lost their original 

 chemical composition, and are changed into stone ; and hence 

 the name of petrifactions or fossils, under which latter term 

 are comprehended all the organized bodies of former epochs, 

 obtained from the earth's crust. Others have entirely dis- 

 appeared, leaving only their forms and sculpture impressed 

 upon the rocks. 



645. The study of these remains and of their position in 

 the rocks constitutes PALAEONTOLOGY ; one of the most essen- 

 tial branches of zoology. Their geological distribution, or 

 the order of their successive appearance namely, the distri- 

 bution of animals in time, is of no less importance than the 



