Contents: Editor’s Introduction; Historical Sketch; Variation Under Domestication; Variation Under Nature; Struggle for Existence; Natural Selection or the Survival of the Fittest; Laws of Variation; Difficulties of the Theory; Miscellaneous Objections to the Theory of Natural Selection; Instinct; Hybridism; On the Imperfections of the Geological Record; On the Geological Succession of Organic Beings; Geographical Distribution; Mutual Affinities of Organic Beings; Recapitulation and Conclusion.