CONTENTS. 



(The numbers refer to the pages of the text.) 



CHAPTER I. 



THE HISTORY OF ORGANISMS, ITS SCOPE AND IMPORTANCE. 



Man an organism among organisms, i. — History of organisms and man's 

 relationship to living things — The discussion not from the zoologi- 

 cal and botanical side, 2. — The geological aspect of the history of 

 organisms — Geological history not a repetition of like events, but a 

 progressive change of phenomena, 3. — Investigation of the laws of 

 evolution — Old notion of an organism contrasted with the new — Work 

 of the paleontologist, 4. — Botanists and zoologists observe individual 

 characters — Paleontologists interested in the history of species, of 

 races, and of groups of organisms, 5. — Organisms and environment, 6. 

 — Geological formations — The organism — Races and their history — 

 The chronological scale, 7. — Theories regarding the length of geologi- 

 cal time, S. 



CHAPTER II. 



THE MAKING OF THE GEOLOGICAL TIME-SCALE. 



The heterogeneous names now in use — Importance of a systematic classi- 

 fication, 10. — Ancient notions of Geology — Beginnings of a scientific 

 system of classification, 11. — Lehmann's classification according to order 

 of formation — Cuvier's, Brongniart's, and Reboul's contributions, 12. 

 — Werner's perfection of the Lehmann classification, 13. — Richard 

 Kirwan, and Geology at the close of the last century, 14. — Geological 

 mountains {Gebirge) and formations, 15. — The formation of sedimentary 

 rocks according to Werner and his school, 16. — Werner's classification 

 of rocks by their mineral characters, 17. — Conybeare and Phillips's per- 

 fection of the Wernerian system — De la Beche — Maclure's application 

 of the system to American rocks, 18. — Amos Eaton's classification of 

 the New York rocks — Principles involved in the Wernerian system of 

 classification, 19. — Fossils substituted for minerals in classifying strati- 

 fied rocks — Cuvier and Brongniart, 20. — William Smith and Lyell — 

 Lyell's classification of the Tertiary into Eocene, Miocene, and Plio- 

 cene, 21. — Extension of the Lyellian system by Forbes, Sedgwick, and 

 Murchison, 22. — Phillips' scheme, 23. — Chronological succession in- 

 cluded in Lyell's system — Dana's elaboration of a geological time-scale, 

 24. — Biological classification of Oppel — Geological terranes and time- 

 periods contrasted, 28. — United States Geological Survey definitions of 

 formation and period — English usage, 30. — Geological systems the 

 standard units of the time-scale — Cambrian system, 31. — Ordovician 

 system, 32.— Silurian system — Devonian system, 33. — Carboniferous 



