There is an extensive secondary literature on Darwin's life and work. Here are some suggested titles that focus Darwin's correspondence, as well as scientific correspondence and letter-writing more generally.

Collections of Darwin's letters

• Barlow, N., ed. 1958. The autobiography of Charles Darwin. London: Collins.
• Burkhardt, F., et al., eds. 1985- The correspondence of Charles Darwin. Cambridge; New York: Cambridge University Press
• Burkhardt, F., ed. 2008. Charles Darwin: the Beagle letters. Cambridge: Cambridge University Press.
• Burkhardt, F., et al., eds. 2008. Evolution: selected letters of Charles Darwin 1860-1870. Cambridge: Cambridge University Press.
• Burkhardt, F., ed. 2008. Origins: selected letters of Charles Darwin, 1822-1859. Anniversary edition. Cambridge : Cambridge University Press.
• Darwin, F., ed. 1887 The life and letters of Charles Darwin, including an autobiographical chapter. London: John Murray.

Sources on scientific correspondence and letter-writing

On Darwin's correspondence:

• Browne, J. 1995-2002. Charles Darwin. 2 vols. London: Jonathan Cape. Esp. pp. 1: 10-13.
• Moore, J. R. 1985. Darwin's Genesis and Revelations. Isis 76: 570-80.
• Secord, J. 1981. Nature's fancy: Charles Darwin and the breeding of pigeons. Isis 72: 163-86.
• Secord, J. 1985. Darwin and the breeders: a social history, in The Darwinian heritage, edited by David Kohn. Princeton: Princeton University Press. Pp. 519-42.
• White, P. 2007. Letters and the scientific life in the age of professionalization, in New Perspectives in British Cultural History, edited by R. Crone. Cambridge Scholars Press.
• White, P. 2008. Correspondence as a Medium of Reception and Appropriation, in The reception of Charles Darwin in Europe, edited by Thomas Glick and Eve-Marie Engels. London: Continuum.

On correspondence in science:

• Goodman, D. 1994. The republic of letters: a cultural history of the French Enlightenment. Ithaca: Cornell University Press. Pp. 136-52.
• Miller, D. P. 1996. Joseph Banks, empire, and 'Centers of calculation' in Late Hanoverian London, in Visions of empire: voyages, botany and representations of nature, edited by D. P. Miller and H. P. Riell. Cambridge: Cambridge University Press. Pp. 21-37.
• Secord, A. 1994. Corresponding interests: artisans and gentlemen in nineteenth-century natural history. British Journal for the History of Science 27: 383-408.
• Shteir, A. B. 1990. Botanical dialogues: Maria Jackson and women's popular science writing in England. Eighteenth-Century Studies 23: 301-17.
• Spary, E. C. 2000. Utopia's garden: French natural history from old regime to revolution. Chicago: University of Chicago Press. Chapter 2.

On the history of letter writing:

• Altman, J. G. 1992. Epistolary conduct: the evolution of the letter manual in France in the eighteenth century. Studies on Voltaire and the Eighteenth Century 304: 866-69.
• Bazerman, C. 2000. Letters and the social grounding of differentiated genres, in Letter writing as a social practice, edited by David Barton and Nigel Hall. Amsterdam; Philadelphia: John Benjamins. Pp. 15-29.
• Chartier, R. 1997. An ordinary kind of writing: model letters and letter-writing in Ancien Régime France, in Correspondence: models of letter-writing from the middle ages to the nineteenth century, edited by R. Chartier et al. Cambridge: Polity Press. Pp. 1-23.
• Earle, R., ed. 1999. Epistolary selves: etters and letter-writers, 1600-1945. Aldershot: Ashgate.
• Hall, N. 1999. The materiality of letter writing, in Letter writing as a social practice, edited by D. Barton and N. Hall. Amsterdam: John Benjamins. Pp. 83-108.
• Hornbeak, K. G. 1934. The compleat letter-writer in English, 1568-1800. Smith College Studies in Modern Languages 15.

On letter writing as literary form:

• Beebee, T. O. 1999. Epistolary fiction in Europe, 1500-1850. New York: Cambridge University Press.
• Favret, M. A. 1993. Romantic correspondence: women, politics, and the fiction of letters. Cambridge: Cambridge University Press.
• MacArthur, E. J. 1990. Extravagant narratives: closure and dynamics in the epistolary form. Princeton: Princeton University Press. Pp. 36-43.

Some 19th-century sources on letter writing:

• Davies, J. 1870. Letter writing. Quarterly Review 129: 220-44.
• Lucas, E. V. 1898. Concerning correspondence. Cornhill Magazine 77: 509-17.
• Lyell, A. 1896. English letter writing in the nineteenth century. Edinburgh Review 183: 306-35.
• Roberts, W. 1843. History of letter-writing from the earliest period to the fifth century. London: William Pickering.