Chapter I: Preface

The science of the earth as illustrated by geological research, is one of the noblest outgrowths of our modern intellectual life. Constituting the sum of all the natural sciences in their application to the history of our world, it affords a very wide and varied scope for mental activity, and deals with some of the grandest problems of space and time and of organic existence. It invites us to be present at the origin of things, and to enter into the very workshop of the Creator. It has, besides, most important and intimate connection with the industrial arts and with the material resources at the disposal of man. Its educational value, as a means of cultivating the powers of observing and reasoning, and of accustoming the mind to deal with large and intricate questions, can scarcely be overrated.

But fully to serve these high ends, the study of geology must be based on a thorough knowledge of the subjects which constitute its elementary data. It must be divested as far as possible of merely local colouring, and of the prejudices of specialists. It must be emancipated from the control of the bald metaphysical speculations so rife in our time, and above all it must be delivered from that materialistic infidelity, which, by robbing nature of the spiritual element, and of its presiding Divinity, makes science dry, barren, and repulsive, diminishes its educational value, and even renders it less efficient for purposes of practical research.

That the want of these preliminary conditions mars much of the popular science of our day is too evident; and I confess that the wish to attempt something better, and thereby to revive the interest in geological study, to attract attention to its educational value, and to remove the misapprehensions which exist in some quarters respecting it, were principal reasons which induced me to undertake the series of papers for the _Leisure Hour_, which are reproduced, with some amendments and extension, in the present work. How far I have succeeded, I must leave to the intelligent and, I trust, indulgent reader to decide. In any case I have presented this many-sided subject in the aspect in which it appears to a geologist whose studies have led him to compare with each other the two great continental areas which are the classic ground of the science, and who retains his faith in those unseen realities of which the history of the earth itself is but one of the shadows projected on the field of time.

To geologists who may glance at the following pages, I would say that, amidst much that is familiar, they will find here and there some facts which may be new to them, as well as some original suggestions and conclusions as to the relations of things, which though stated in familiar terms, I have not advanced without due consideration of a wide range of facts, To the general reader I have endeavoured to present the more important results of geological investigation divested of technical difficulties, yet with a careful regard to accuracy of statement, and in such a manner as to invite to the farther and more precise study of the subject in nature, and in works which enter into technical details. I have endeavoured as far as possible to mention the authors of important discoveries; but it is impossible in a work of this kind to quote authority for every statement, while the omission of much important matter relating to the topics discussed is also unavoidable. Shortcomings in these respects must be remedied by the reader himself, with the aid of systematic text-books. Those who may desire any farther explanation of the occasional allusions to the record of creation in Genesis, will find this in my previously published volume entitled "Archaia."

J. W. D,

McGill College, Montreal,
_January, 1873_.

CONTENTS.

PAGE

Chapter I.--The Genesis Of The Earth.

Uniformity and Progress.--Internal Heat.--Nebular
Theory.--Probable Condition of the Primitive World 1

Chapter II.--The Eozoic Ages.

The Laurentian Rocks.--Their Character and
Distribution.--The Conditions of their Deposition.--Their
Metamorphism.--Eozoon Canadense.--Laurentian Vegetation 17

Chapter III.--The Primordial or Cambrian Age.

Connection of the Laurentian and Primordial.--Animals
of the Primordial Seas.--Lingula, Trilobites, Oldhamia,
etc.--The terms Cambrian and Silurian.--Statistics of
Primordial Life 36

Chapter IV.--The Silurian Ages.

Geography of the Continental Plateaus.--Life of the
Silurian.--Reign of Invertebrates.--Corals, Crinoids,
Mollusks, Crustaceans.--The First Vertebrates.
Silurian Fishes.--Land Plants 56

Chapter V.--The Devonian or Erian Age.

Physical Character of the Age.--Difference of Deposits in
Marginal and Continental Areas.--Specialisation of
Physical Geography.--Corals, Crustaceans, Fishes,
Insects, Plants 81

Chapter VI.--The Carboniferous Age.

Perfection of Palæozoic Life.--Carboniferous
Geography.--Colours of Sediments.--Vegetation.--Origin
of Coal.--Land Life.--Reptiles, Land Snails, Millipedes,
etc.--Oceanic Life 109

Chapter VII.--The Permian Age.

Movements of the Land.--Plication of the Crust.--Chemical
Conditions of Dolomite, etc.--Geographical
Results of Permian Movements.--Life of the Period.
Summary of Palæozoic History 160

Chapter VIII.--The Mesozoic Ages.

Characters of the Trias.--Summary of Changes in the
Triassic and Cretaceous Periods.--Changes of the
Continental Plateaus.--Relative Duration of the
Palæozoic and Mesozoic.--Mesozoic Forests.--Land
Animals.--The reign of Reptiles.--Early Mammals
and Birds 188

Chapter IX.--The Mesozoic Ages (continued).

Animals of the Sea.--Great Sea Lizards, Fishes,
Cephalopods, etc.--Chalk and its History.--Tabular
View of the Mesozoic Ages 211

Chapter X.--The Neozoic Ages.

Physical Changes at the end of Mesozoic.--Subdivisions
of the Neozoic.--Great Eocene Seas.--Land Animals
and Plants. Life of the Miocene.--Reign of Mammals 235

Chapter XI.--The Neozoic Ages (_continued_).

Later Vegetation.--The Animals of the Pliocene Period.
Approach of the Glacial Period.--Character of the
Post-pliocene or Glacial 258

Chapter XII.--Close of the Post-pliocene, and Advent or Man.

Connection of Geological and Human History.--The Post-glacial
Period.--Its Relations to the Pre-Historic Human
Period.--Elevation of Post-Pliocene Land.--Introduction of
Man.--Subsidence and Re-elevation.--Calculations as to
Time.--Tabular View of the Neozoic Ages 282

Chapter XIII.--Advent Of Man (_continued_).

Relations of Post-pliocene and Modern Animals.--Cavern
Deposits.--Kent's Cave.--General Remarks. 299

Chapter XIV.--Primitive Man.

Theory of Evolution as applied to Man.--Its Demands.--Its
Deficiencies.--Fallacious Character of Arguments of
Derivationists. Hypothesis of Creation.--Its Demands
and Advantages 316