Harvard Classics
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. Prin...
Natural Selection: its power compared with man’s selection, its power on characters of trifling importance, its power at all ages and on both sexes. Sexual Selection. On the gen...
27. CHAPTER XIII.CLASSIFICATION, groups subordinate to groups. Natural system. Rules and difficulties in classification, explained on the theory of descent with modification. Classification of v...
28. CHAPTER XIV.Recapitulation of the difficulties on the theory of Natural Selection. Recapitulation of the general and special circumstances in its favour. Causes of the general belief in the...
19. CHAPTER V.Effects of external conditions. Use and disuse, combined with natural selection; organs of flight and of vision. Acclimatisation. Correlation of growth. Compensation and economy...
21. CHAPTER VII.Instincts comparable with habits, but different in their origin. Instincts graduated. Aphides and ants. Instincts variable. Domestic instincts, their origin. Natural instincts o...
15. CHAPTER I.Causes of Variability. Effects of Habit. Correlation of Growth. Inheritance. Character of Domestic Varieties. Difficulty of distinguishing between Varieties and Species. Origin...
25. CHAPTER XI.Present distribution cannot be accounted for by differences in physical conditions. Importance of barriers. Affinity of the productions of the same continent. Centres of creatio...
20. CHAPTER VI.Difficulties on the theory of descent with modification. Transitions. Absence or rarity of transitional varieties. Transitions in habits of life. Diversified habits in the same...
24. CHAPTER X.On the slow and successive appearance of new species. On their different rates of change. Species once lost do not reappear. Groups of species follow the same general rules in t...
22. CHAPTER VIII.Distinction between the sterility of first crosses and of hybrids. Sterility various in degree, not universal, affected by close interbreeding, removed by domestication. Laws go...
23. CHAPTER IX.On the absence of intermediate varieties at the present day. On the nature of extinct intermediate varieties; on their number. On the vast lapse of time, as inferred from the ra...
26. CHAPTER XII.Distribution of fresh-water productions. On the inhabitants of oceanic islands. Absence of Batrachians and of terrestrial Mammals. On the relation of the inhabitants of islands...
17. CHAPTER III.Bears on natural selection. The term used in a wide sense. Geometrical powers of increase. Rapid increase of naturalised animals and plants. Nature of the checks to increase. Co...
16. CHAPTER II.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...
14. CHAPTER 14. RECAPITULATION AND CONCLUSION.Recapitulation of the difficulties on the theory of Natural Selection. Recapitulation of the general and special circumstances in its favour. Causes of the general belief in the...
4. CHAPTER 4. NATURAL SELECTION.Natural Selection: its power compared with man’s selection, its power on characters of trifling importance, its power at all ages and on both sexes. Sexual Selection. On the gen...
10. CHAPTER 10. ON THE GEOLOGICAL SUCCESSION OF ORGANIC BEINGS.On the slow and successive appearance of new species. On their different rates of change. Species once lost do not reappear. Groups of species follow the same general rules in t...
13. CHAPTER 13. MUTUAL AFFINITIES OF ORGANIC BEINGS: MORPHOLOGY:CLASSIFICATION, groups subordinate to groups. Natural system. Rules and difficulties in classification, explained on the theory of descent with modification. Classification of v...
3. CHAPTER 3. STRUGGLE FOR EXISTENCE.Bears on natural selection. The term used in a wide sense. Geometrical powers of increase. Rapid increase of naturalised animals and plants. Nature of the checks to increase. Co...
8. CHAPTER 8. HYBRIDISM.Distinction between the sterility of first crosses and of hybrids. Sterility various in degree, not universal, affected by close interbreeding, removed by domestication. Laws go...
6. CHAPTER 6. DIFFICULTIES ON THEORY.Difficulties on the theory of descent with modification. Transitions. Absence or rarity of transitional varieties. Transitions in habits of life. Diversified habits in the same...
9. CHAPTER 9. ON THE IMPERFECTION OF THE GEOLOGICAL RECORD.On the absence of intermediate varieties at the present day. On the nature of extinct intermediate varieties; on their number. On the vast lapse of time, as inferred from the ra...
5. CHAPTER 5. LAWS OF VARIATION.Effects of external conditions. Use and disuse, combined with natural selection; organs of flight and of vision. Acclimatisation. Correlation of growth. Compensation and economy...
1. 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...
2. 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...
11. CHAPTER 11. GEOGRAPHICAL DISTRIBUTION.Present distribution cannot be accounted for by differences in physical conditions. Importance of barriers. Affinity of the productions of the same continent. Centres of creatio...
7. CHAPTER 7. INSTINCT.Instincts comparable with habits, but different in their origin. Instincts graduated. Aphides and ants. Instincts variable. Domestic instincts, their origin. Natural instincts o...
12. CHAPTER 12. GEOGRAPHICAL DISTRIBUTION—_continued_.Distribution of fresh-water productions. On the inhabitants of oceanic islands. Absence of Batrachians and of terrestrial Mammals. On the relation of the inhabitants of islands...