The Public Domain Review flips through Darwin’s unusual photo collection and his correspondence with neurologist James Crichton-Browne. The correspondence between Darwin and Crichton-Browne led Darwin to write The Expression of Emotions of Man and Animals. Darwin found Crichton-Browne’s help so invaluable that he even wanted to list the neurologist as the book’s co-author (an offer Crichton-Browne politely declined).
