Contents

  1. Introduction
  2. Chapter 1: Variation under Domestication
  3. Causes of Variability
  4. Effects of Habit and of the Use or Disuse of Parts; Correlated Variation; Inheritance
  5. Character of Domestic Varieties; difficulty of distinguishing between Varieties and Species; origin of Domestic Varieties from one or more Species
  6. Breeds of the Domestic Pigeon, their Differences and Origin
  7. Principles of Selection anciently followed, and their Effects
  8. Unconscious Selection
  9. Circumstances favourable to Man's Power of Selection
  10. Chapter 2: Variation under Nature
  11. Individual Differences
  12. Doubtful Species
  13. Wide-ranging, much-diffused, and common Species vary most
  14. Species of the Larger Genera in each Country vary more Frequently than the Species of the Smaller Genera
  15. Many of the Species included within the Larger Genera resemble Varieties in being very closely, but unequally, related to each other, and in having restricted ranges
  16. Summary
  17. Chapter 3: Struggle for Existence
  18. Its bearing on natural selection
  19. The term used in a wide sense
  20. Geometrical powers of increase
  21. Rapid increase of naturalised animals and plants
  22. Nature of the checks to increase
  23. Competition universal
  24. Effects of climate
  25. Protection from the number of individuals
  26. Complex relations of all animals and plants throughout nature
  27. Struggle for life most severe between individuals and varieties of the same species; often severe between species of the same genus
  28. The relation of organism to organism the most important of all relations
  29. Chapter 4: Natural Selection
  30. Natural Selection
  31. Its power compared with man's selection
  32. Its power on characters of trifling importance
  33. Its power at all ages and on both sexes
  34. Sexual Selection
  35. On the generality of intercrosses between individuals of the same species
  36. Circumstances favourable and unfavourable to Natural Selection, namely, intercrossing, isolation, number of individuals
  37. Slow action
  38. Extinction caused by Natural Selection
  39. Divergence of Character, related to the diversity of inhabitants of any small area, and to naturalisation
  40. Action of Natural Selection, through Divergence of Character and Extinction, on the descendants from a common parent
  41. Explains the Grouping of all organic beings
  42. Chapter 5: Laws of Variation
  43. Effects of external conditions
  44. Use and disuse, combined with natural selection; organs of flight and of vision
  45. Acclimatisation
  46. Correlation of growth
  47. Compensation and economy of growth
  48. False correlations
  49. Multiple, rudimentary, and lowly organised structures variable
  50. Parts developed in an unusual manner are highly variable: specific characters more variable than generic: secondary sexual characters variable
  51. Species of the same genus vary in an analogous manner
  52. Reversions to long-lost characters
  53. Summary
  54. Chapter 6: Difficulties on Theory
  55. Difficulties on the theory of descent with modification
  56. Transitions
  57. Absence or rarity of transitional varieties
  58. Transitions in habits of life
  59. Diversified habits in the same species
  60. Species with habits widely different from those of their allies
  61. Organs of extreme perfection
  62. Means of transition
  63. Cases of difficulty
  64. Natura non facit saltum
  65. Organs of small importance
  66. Organs not in all cases absolutely perfect
  67. The law of Unity of Type and of the Conditions of Existence embraced by the theory of Natural Selection
  68. Chapter 7: Instinct
  69. Instincts comparable with habits, but different in their origin
  70. Instincts graduated
  71. Aphides and ants
  72. Instincts variable
  73. Domestic instincts, their origin
  74. Natural instincts of the cuckoo, ostrich, and parasitic bees
  75. Slave-making ants
  76. Hive-bee, its cell-making instinct
  77. Difficulties on the theory of the Natural Selection of instincts
  78. Neuter or sterile insects
  79. Summary
  80. Chapter 8: Hybridism
  81. Distinction between the sterility of first crosses and of hybrids
  82. Sterility various in degree, not universal, affected by close interbreeding, removed by domestication
  83. Laws governing the sterility of hybrids
  84. Sterility not a special endowment, but incidental on other differences
  85. Causes of the sterility of first crosses and of hybrids
  86. Parallelism between the effects of changed conditions of life and crossing
  87. Fertility of varieties when crossed and of their mongrel offspring not universal
  88. Hybrids and mongrels compared independently of their fertility
  89. Summary
  90. Chapter 9: On the Imperfection of the Geological Record
  91. On the absence of intermediate varieties at the present day
  92. On the nature of extinct intermediate varieties; on their number
  93. On the vast lapse of time, as inferred from the rate of deposition and of denudation
  94. On the poorness of our paleontological collections
  95. On the intermittence of geological formations
  96. On the absence of intermediate varieties in any one formation
  97. On the sudden appearance of groups of species
  98. On their sudden appearance in the lowest known fossiliferous strata
  99. Chapter 10: On the Geological Succession of Organic Beings
  100. On the slow and successive appearance of new species
  101. On their different rates of change
  102. Species once lost do not reappear
  103. Groups of species follow the same general rules in their appearance and disappearance as do single species
  104. On Extinction
  105. On simultaneous changes in the forms of life throughout the world
  106. On the affinities of extinct species to each other and to living species
  107. On the state of development of ancient forms
  108. On the succession of the same types within the same areas
  109. Summary of preceding and present chapters
  110. Chapter 11: Geographical Distribution
  111. Present distribution cannot be accounted for by differences in physical conditions
  112. Importance of barriers
  113. Affinity of the productions of the same continent
  114. Centres of creation
  115. Means of dispersal, by changes of climate and of the level of the land, and by occasional means
  116. Dispersal during the Glacial period co-extensive with the world
  117. Chapter 12: Geographical Distribution—continued
  118. Distribution of fresh-water productions
  119. On the inhabitants of oceanic islands
  120. Absence of Batrachians and of terrestrial Mammals
  121. On the relation of the inhabitants of islands to those of the nearest mainland
  122. On colonisation from the nearest source with subsequent modification
  123. Summary of the last and present chapters
  124. Chapter 13: Mutual Affinities of Organic Beings: Morphology: Embryology: Rudimentary Organs
  125. Classification, groups subordinate to groups
  126. Natural system
  127. Rules and difficulties in classification, explained on the theory of descent with modification
  128. Classification of varieties
  129. Descent always used in classification
  130. Analogical or adaptive characters
  131. Affinities, general, complex and radiating
  132. Extinction separates and defines groups
  133. Morphology, between members of the same class, between parts of the same individual
  134. Embryology, laws of, explained by variations not supervening at an early age, and being inherited at a corresponding age
  135. Rudimentary organs; their origin explained
  136. Summary
  137. Chapter 14: Recapitulation and Conclusion
  138. Recapitulation of the difficulties on the theory of Natural Selection
  139. Recapitulation of the general and special circumstances in its favour
  140. Causes of the general belief in the immutability of species
  141. How far the theory of natural selection may be extended
  142. Effects of its adoption on the study of Natural history
  143. Concluding remarks
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Cover Introduction