CONTENTS

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Charles Darwin

ESSAY OF 1842

PART I

  • § i. On variation under domestication, and on the principles of selection 1
  • § ii. On variation in a state of nature and on the natural means of selection 4
  • § iii. On variation in instincts and other mental attributes 17

PART II

  • §§ iv. and v. On the evidence from Geology. (The reasons for combining the two sections are given in the Introduction) 22
  • § vi. Geographical distribution 29
  • § vii. Affinities and classification 35
  • § viii. Unity of type in the great classes 38
  • § ix. Abortive organs 45
  • § x. Recapitulation and conclusion 48

ESSAY OF 1844

PART I

CHAPTER I
ON THE VARIATION OF ORGANIC BEINGS UNDER DOMESTICATION; AND ON THE PRINCIPLES OF SELECTION.

  • Variation
  • On the hereditary tendency
  • Causes of Variation
  • On Selection
  • Crossing Breeds
  • Whether our domestic races have descended from one or more wild stocks
  • Limits to Variation in degree and kind
  • In what consists Domestication
  • Summary 57-80

CHAPTER II
ON THE VARIATION OF ORGANIC BEINGS IN A WILD STATE; ON THE NATURAL MEANS OF SELECTION; AND ON THE COMPARISON OF DOMESTIC RACES AND TRUE SPECIES.

  • Variation
  • Natural means of Selection
  • Differences between “Races” and “Species”:—first, in their trueness or variability
  • Difference between “Races” and “Species” in fertility when crossed
  • Causes of Sterility in Hybrids
  • Infertility from causes distinct from hybridisation
  • Points of Resemblance between “Races” and “Species”
  • External characters of Hybrids and Mongrels
  • Summary
  • Limits of Variation 81-111

CHAPTER III
ON THE VARIATION OF INSTINCTS AND OTHER MENTAL ATTRIBUTES UNDER DOMESTICATION AND IN A STATE OF NATURE; ON THE DIFFICULTIES IN THIS SUBJECT; AND ON ANALOGOUS DIFFICULTIES WITH RESPECT TO CORPOREAL STRUCTURES.

  • Variation of mental attributes under domestication
  • Hereditary habits compared with instincts
  • Variation in the mental attributes of wild animals
  • Principles of Selection applicable to instincts
  • Difficulties in the acquirement of complex instincts by Selection
  • Difficulties in the acquirement by Selection of complex corporeal structures 112-132

PART II
ON THE EVIDENCE FAVOURABLE AND OPPOSED TO THE VIEW THAT SPECIES ARE NATURALLY FORMED RACES, DESCENDED FROM COMMON STOCKS.

CHAPTER IV
ON THE NUMBER OF INTERMEDIATE FORMS REQUIRED ON THE THEORY OF COMMON DESCENT; AND ON THEIR ABSENCE IN A FOSSIL STATE 133-143

CHAPTER V
GRADUAL APPEARANCE AND DISAPPEARANCE OF SPECIES. 144-150

  • Gradual appearance of species
  • Extinction of species

CHAPTER VI
ON THE GEOGRAPHICAL DISTRIBUTION OF ORGANIC BEINGS IN PAST AND PRESENT TIMES.

SECTION FIRST 151-174

  • Distribution of the inhabitants in the different continents
  • Relation of range in genera and species
  • Distribution of the inhabitants in the same continent
  • Insular Faunas
  • Alpine Floras
  • Cause of the similarity in the floras of some distant mountains
  • Whether the same species has been created more than once
  • On the number of species, and of the classes to which they belong in different regions

SECOND SECTION 174-182

  • Geographical distribution of extinct organisms
  • Changes in geographical distribution
  • Summary on the distribution of living and extinct organic beings

SECTION THIRD 183-197

  • An attempt to explain the foregoing laws of geographical distribution, on the theory of allied species having a common descent
  • Improbability of finding fossil forms intermediate between existing species

CHAPTER VII
ON THE NATURE OF THE AFFINITIES AND CLASSIFICATION
OF ORGANIC BEINGS. 198-213

  • Gradual appearance and disappearance of groups
  • What is the Natural System?
  • On the kind of relation between distinct groups
  • Classification of Races or Varieties
  • Classification of Races and Species similar
  • Origin of genera and families

CHAPTER VIII
UNITY OF TYPE IN THE GREAT CLASSES; AND MORPHOLOGICAL STRUCTURES.

  • Unity of Type
  • Morphology
  • Embryology
  • Attempt to explain the facts of embryology
  • On the graduated complexity in each great class
  • Modification by selection of the forms of immature animals
  • Importance of embryology in classification
  • Order in time in which the great classes have first appeared 214-230

CHAPTER IX
ABORTIVE OR RUDIMENTARY ORGANS.

  • The abortive organs of Naturalists
  • The abortive organs of Physiologists
  • Abortion from gradual disuse 231-238

CHAPTER X
RECAPITULATION AND CONCLUSION.

  • Recapitulation
  • Why do we wish to reject the Theory of Common Descent?
  • Conclusion 239-255
  • Index 257
  • Portrait frontispiece
  • Facsimile to face p. 50
                                                                                                                                                                                                                                                                                                           

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