Murray advertised CD’s forthcoming book, Variation, in the Reader, 15 April 1865, p. 427. The notice is under the heading ‘Mr. Murray’s quarterly list of works in the press’, and the title given is ‘Domesticated Animals and Cultivated Plants, or the Principles of Variation, Inheritance, Re-union, Crossing, Interbreeding, and Selection under Domestication’. The word ‘re-union’ was a misprint for ‘reversion’ (see Correspondence vol. 13, letter to John Murray, 2 June [1865]). Variation was not published until 1868.