London : printed by W. Closes and Sons for John Murray, 1866. Fourth edition, second state (eighth thousand). Octavo, original green cloth, boards blocked in blind, spine gilt (light bumping to corners, very minor stains), green endpapers, contemporary owner's inscription in pencil 'M Purser 1867' to half-title, pp. xxi; [blank], 593; [blank] 32 (publisher's catalogue dated January 1865), folding lithographic plate by William West after Darwin, one quire slightly sprung, a fine copy of the fourth edition, entirely unsophisticated, crisp, complete and unrestored. The first edition of 1859, a great rarity, is described in Freeman as ""... the most important biological work ever written.""; Dibner, ""... the most important single work in science.""; Printing & the Mind of Man, ""... revolutionized our methods of thinking and our outlook on the natural order of things. The recognition that constant change is the order of the universe had been finally established and a vast…