The succession of life upon the globe--Gradual and successive introduction of life-forms--What is meant by "lower" and "higher" groups of animals and plants--Succession in time of the great groups of animals in the main corresponding with their zoological order--Identical phenomena in the vegetable kingdom--Persistent types of life--High organisation of many early forms--Bearings of Palæontology on the general doctrine of Evolution. APPENDIX.--Tabular view of the chief Divisions of the Animal Kingdom. GLOSSARY. INDEX. LIST OF ILLUSTRATIONS FIG. 1. Cast of _Trigonia longa_. 2. Microscopic section of the wood of a fossil Conifer. 3. Microscopic section of the wood of the Larch. 4. Section of Carboniferous strata, Kinghorn, Fife. 5. Diagram illustrating the formation of stratified deposits. 6. Microscopic section of a calcareous breccia. 7. Microscopic section of White Chalk. 8. Organisms in Atlantic Ooze. 9. Crinoidal marble. 10. Piece of Nummulitic limestone, Pyramids. 11. Microscopic section of Foraminiferal limestone--Carboniferous, America. 12. Microscopic section of Lower Silurian limestone. 13. Microscopic section of oolitic limestone, Jurassic. 14. Microscopic section of oolitic limestone, Carboniferous. 15. Organisms in Barbadoes earth. 16. Organisms in Richmond earth. 17. Ideal section of the crust of the earth. 18. Unconformable junction of Chalk and Eocene rocks. 19. Erect trunk of a _Sigillaria_. 20. Diagrammatic section of the Laurentian rocks. 21. Microscopic section of Laurentian limestone. 22. Fragment of a mass of _Eozoön Canadense_. 23. Diagram illustrating the structure of _Eozoön_. 24. Microscopic section of _Eozoön Canadense_. 25. _Nonionina_ and _Gromia_. 26. Group of shells of living _Foraminifera_. 27. Diagrammatic section of Cambrian strata. 28. _Eophyton Linneanum_. 29. _Oldhamia antiqua_. 30. _Scolithus Canadensis_. 31. Group of Cambrian Trilobites. 32. Group of characteristic Cambrian fossils. 33. Fragment of _Dictyonema sociale_. 34. Generalised section of the Lower Silurian rocks of Wales. 35. Generalised section of the Lower Silurian rocks of North America. 36. _Licrophycus Ottawaensis_. 37. _Astylospongia proemorsa_. 38. _Stromatopora rugosa_. 39. _Dichograptus octobrachiatus_. 40. _Didymograptus divaricatus_. 41. _Diplograptus pristis_. 42. _Phyllograptus typus_. 43. _Zaphrentis Stokesi_. 44. _Strombodes pentagonus_. 45. _Columnaria alveolata_. 46. Group of Cystideans. 47. Group of Lower Silurian Crustaceans. 48. _Ptilodictya falciformis_. 49. _Ptilodictya Schafferi_. 50. Group of Lower Silurian Brachiopods. 51. Group of Lower Silurian Brachiopods. 52. _Murchisonia gracilis_. 53. _Bellerophon argo_. 54. _Maclurea crenulata_. 55. _Orthoceras crebriseptum_. 56. Restoration of _Orthoceras_. 57. Generalised section of the Upper Silurian rocks. 58. _Monograptus priodon_. 59. _Halysites catenularia_ and _H. agglomerata_. 60.