English naturalist and author of one of the most influential books in the history of science, On the Origin of the Species by Means of Natural Selection (1859). Fountain pen signature, “Charles Darwin, Down, Kent,” on an off-white 3.75 x 2.75 card, dated April 14, 1880. In fine condition, with a light overall shade of toning. COA John Reznikoff/PSA/DNA and R&R COA.
