John Blackwall - Correspondence With Charles Darwin

Correspondence With Charles Darwin

Blackwall wrote four letters on the subject of spiders to Charles Darwin, dated 12 February 1868, 18 February 1868, 10 August 1869 and 8 September 1869. They survive in the Darwin Archive at Cambridge University Library. The first, second, and third letters are in direct response to communications from Darwin, though the whereabouts of these letters, presumably kept by Blackwall, are unknown. Their subject matter is, broadly, variation among spiders.

The first letter begins "I wish it were in my power to give satisfactory answers to the questions contained in your letter of the 10th instant. Adult spiders of the same species differ so remarkably in size and colour, and that independently to all appearance of the situations in which they are found, that I am unable to assign an adequate cause for this extraordinary fact..."