BOOKS BY DARWIN, WITH THE ABBREVIATIONS USED IN REFERRING TO THEM IN THE NOTES
The American revised edition is referred to, unless otherwise specified
| A Monograph on the sub-class Cirripedia.—The Balanidæ—The Verrucidæ. | Cirripedia. |
| The Descent of Man and Selection in Relation to Sex. | Descent. |
| The Different Forms of Flowers on Plants of the Same Species. | Different Forms of Flowers. |
| The Effects of Cross and Self Fertilization in the Vegetable Kingdom. | Cross and Self Fertilization. |
| Krause, Ernst, Erasmus Darwin (translated from the German by W. S. Dallas, with a preliminary notice by Charles Darwin). | Krause. |
| The Expression of the Emotions in Man and Animals. | Expression. |
| The Formation of Vegetable Mould through the Action of Worms. | Worms. |
| Geological Observations. | Geological Observations. |
| Insectivorous Plants. | Insectivorous Plants. |
| Journal of Researches into the Natural History and Geology of the Countries Visited during the Voyage of H.M.S. Beagle Round the World. | Beagle Journal. |
| More Letters of Charles Darwin, two volumes. | More Letters. |
| The Movements and Habits of Climbing Plants. | Climbing Plants. |
| The Origin of Species. | Origin. |
| The Power of Movement in Plants. | Movement in Plants. |
| The Variation of Animals and Plants under Domestication, two volumes. | Animals and Plants. |
| The Various Contrivances by which Orchids are Fertilized by Insects. | Orchids. |
BOOKS BIOGRAPHICAL AND CRITICAL MOST FREQUENTLY REFERRED TO IN THE NOTES, WITH THE ABBREVIATIONS USED
| Aristotle, Historia Animalium, translated by D’Arcy Wentworth Thompson. | Historia Animalium. |
| Castle, W. E., Genetics and Eugenics. | Genetics and Eugenics. |
| Conklin, Edwin Grant, The Direction of Human Evolution. | Evolution. |
| Darwin, Emma, A Century of Family Letters, two volumes. | Family Letters. |
| Darwin, The Life and Letters of Charles Darwin, two volumes. | Life. |
| De Vries, Hugo, Species and Varieties, Their Origin by Mutation. | Species and Varieties. |
| Goncourts, Edmond et Jules, Journal des Goncourts, nine volumes. | Goncourts, Journal. |
| Gray, Asa, Letters of, edited by Jane Loring Gray, two volumes. | Gray Letters. |
| Grant Duff, Sir Mountstuart E., Notes from a Diary, fourteen volumes, 1851-1901. | Grant Duff. |
| Huxley, Thomas H., Darwiniana (the second volume of Collected Essays). | Darwiniana. |
| Huxley, Thomas H., Life and Letters of, by his son Leonard, two volumes. | Huxley, Life. |
| Lull Richard, Harry Burr Ferris, George Howard Parker, James Rowland Angell, Albert Galloway Keller, Edwin Grant Conklin, The Evolution of Man. | Lull. |
| Morgan, Thomas Hunt, Evolution and Adaptation. | Evolution and Adaptation. |
| Osborn, Henry Fairfield, The Earth Speaks to Bryan. | The Earth Speaks. |
| Osborn, From the Greeks to Darwin. | Greeks to Darwin. |
| Osborn, Henry Fairfield, Impressions of Great Naturalists. | Great Naturalists. |
| Parker, George Howard, What Evolution Is. | What Evolution Is. |
| Pearson, Karl, The Grammar of Science. | Grammar of Science. |
| Thoreau, Henry, Journal, fourteen volumes. | Journal. |
| Vallery-Radot, Pasteur. | Vallery-Radot, Pasteur. |
| Wallace, Alfred Russell, My Life, two volumes. | Wallace, Life. |
| Whitehead, Alfred North, Science and the Modern World. | Science and the Modern World. |
NOTES
CHAPTER I: THE OBSERVER
[1] Journal des Goncourts, May 1, 1857, vol. I, p. 182.
[2] Ben Jonson, The Poetaster, act II, scene 1.
[3] Sentimental Journey, ‘In the Street.’