“To conclude, therefore, let no man out of a weak conceit of sobriety, or an ill-applied moderation, think or maintain, that a man can search too far or be too well studied in the book of God’s word, or in the book of God’s works; divinity or philosophy; but rather let men endeavour an endless progress or proficience in both.”

BACON: Advancement of Learning.

Down, Bromley, Kent,
October, 1st, 1859.

Contents

[INTRODUCTION.]
[1. VARIATION UNDER DOMESTICATION.]
[2. VARIATION UNDER NATURE.]
[3. STRUGGLE FOR EXISTENCE.]
[4. NATURAL SELECTION.]
[5. LAWS OF VARIATION.]
[6. DIFFICULTIES ON THEORY.]
[7. INSTINCT.]
[8. HYBRIDISM.]
[9. ON THE IMPERFECTION OF THE GEOLOGICAL RECORD.]
[10. ON THE GEOLOGICAL SUCCESSION OF ORGANIC BEINGS.]
[11. GEOGRAPHICAL DISTRIBUTION.]
[12. GEOGRAPHICAL DISTRIBUTION—continued.]
[13. MUTUAL AFFINITIES OF ORGANIC BEINGS: MORPHOLOGY:]
[14. RECAPITULATION AND CONCLUSION.]
[INDEX]

DETEAILED CONTENTS. ON THE ORIGIN OF SPECIES.

[INTRODUCTION.]

[CHAPTER I. VARIATION UNDER DOMESTICATION.]
Causes of Variability.
Effects of Habit.
Correlation of Growth.
Inheritance.
Character of Domestic Varieties.
Difficulty of distinguishing between Varieties and Species.
Origin of Domestic Varieties from one or more Species.
Domestic Pigeons, their Differences and Origin.
Principle of Selection anciently followed, its Effects.
Methodical and Unconscious Selection.
Unknown Origin of our Domestic Productions.
Circumstances favourable to Man’s power of Selection.

[CHAPTER 2. VARIATION UNDER NATURE.]
Variability.
Individual Differences.
Doubtful species.
Wide ranging, much diffused, and common species vary most.
Species of the larger genera in any country vary more than the species of the smaller genera.
Many of the species of the larger genera resemble varieties in being very closely, but unequally, related to each other, and in having restricted ranges.