SCIENCE OF FOSSIL LIFE 329 



Summary.- -The chief steps up to this time in the growth 

 of the science of fossil life may now be set forth in cate- 

 gories, though we must remember that the advances pro- 

 ceeded concurrently and were much intermingled, so that, 

 whatever arrangement we may adopt, it does not represent 

 a strict chronological order of events: 



I. The determination of the nature of fossils. Owing to 

 the labors of Da Vinci, Steno,and Cuvier,the truth was estab- 

 lished that fossils are the remains of former generations of 

 animals and plants. 



II. The comparison of organic fossils with living forms 

 that was instituted on a broad scale by Cuvier resulted in the 

 conclusion that some of the fossils belong to extinct races. 

 The belief of Cuvier that entire populations became extinct 

 simultaneously, led him to the theory of catastrophism. The 

 observations of Lamarck, that, while some species disappear, 

 others are continued and pass through transmutations, were 

 contrary to that theory. 



III. The recognition that the stratified rocks in which 

 fossils are distributed are sedimentary deposits of gradual 

 formation. This observation and the following took the 

 ground from under the theory that fossils had been deposited 

 during the Mosaic deluge. 



IV. The discovery by William Smith that the arrangement 

 of fossils within rocks is always the same, and the relative 

 age of rocks may be determined by an examination of their 

 fossil contents. 



Upon the basis of the foregoing, we come to the next 

 advance, viz.: 



V. The application of this knowledge to the determination 

 of the history of the earth. 



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Fossil Remains as an Index to the Past History of the 

 Earth.- -The most advanced and enlightened position that 

 had been taken in reference to the fossil series during the 



