This was rewritten as chapter 6 of 'Origin of species': 'Difficulties on theory', with sections on 'Transitional varieties', pp 175-179, and chapter 7 of 'Origin of species': 'Instinct' and 'Hive Bees'. Comprises notes, abstracts, printed material, drafts and correspondence with John Lubbock, John Brodie Innes, John David Glennie Jr, George Henry Kendrick Thwaites, Edward Blyth, J.D. Hooker, G.R. Waterhouse and Hensleigh Wedgwood.