1. Alfred Russel Wallace, Darwinism: An Exposition of Natural Selection, with Some of Its Applications (New York: Humboldt, 1889), p. 77.
2. Arnold C. Brackman, A Delicate Arrangement: The Strange Case of Charles Darwin and Alfred Russel Wallace (New York: Times Books, 1980); John Langdon Brooks, Just before the Origin: Alfred Russel Wallace's Theory of Evolution (New York: Columbia University Press, 1984); Janet Browne, ?Darwin's Botanical Arithmetic and the ?Principle of Divergence?, 1854?1858?, J. Hist. Biol., 13 (1980), 53?89; idem, The Secular Ark: Studies in the History of Biogeography (New Haven: Yale University Press, 1983); Howard E. Gruber, Darwin on Man: A Psychological Study of Scientific Creativity, Together with Darwin's Early and Unpublished Notebooks, transcribed and annotated by Paul H. Barrett (New York: Dutton, 1974); H. Lewis McKinney, Wallace and Natural Selection, Yale Studies in the History of Science and Medicine, no. 8 (New Haven: Yale University Press, 1972; authorized facsimile, Ann Arbor: University Microfilms International, 1984); Dov Ospovat, The Development of Darwin's Theory: Natural History, Natural Theology, and Natural Selection, 1838?1859 (Cambridge: Cambridge University Press, 1981); Silvan S. Schweber, ?Darwin and the Political Economists: Divergence of Character?, J. Hist. Biol., 13 (1980), 195?289. Reviews: Peter J. Bowler, ?Wallace and Darwinism?, Science, 224 (1984), 277?278 [a review of Brooks above]; David Kohn, ?On the Origin of the Principle of Diversity?, Science, 213 (1981), 1105?1108 [a review of Brackman above]; Gareth Nelson, ?Just before the Origin?, Syst. Zool., 33 (1984), 248?249 [a review of Brooks above]. In addition: Barbara G. Beddall, ?Wallace, Darwin, and the Theory of Natural Selection: A Study in the Development of Ideas and Attitudes?, J. Hist. Biol., 1 (1968), 261?323; Frederick Burkhardt and Sydney Smith, eds. A Calendar of the Correspondence of Charles Darwin, 1821?1882 (New York: Garland, 1985) (letter numbers used throughout this paper are taken from the Calendar; see below, n. 176).
3. Kohn, ?Origin of Principle?, p. 1105.
4. For a recent summarizing of the literature on divergence, see David R. Oldroyd, ?How Did Darwin Arrive at His Theory? The Secondary Literature to 1982?, Hist. Sci., 22 (1984), 353?357, 360, 373n44 Oldroyd notes that ?there have been some insinuations and accusations in the literature that Darwin filched the divergence principle from Wallace....And now that we have Dov Ospovat's reconstruction of how Darwin arrived at the principle, the accusations against Darwin on this matter can, I think, be discounted? (p. 353).
5. Kohn, ?Origin of Principle?, p. 1108.