2009 marks a double celebration for Darwin: the bi-centenary of his birth in 1809 and the 150th anniversary of the publication of the Origin in 1859. This third edition of Darwin's Plots is a contribution to that celebration. In approaching the material again I decided not to revise the original text (beyond a couple of errors). For the second edition (2000) I added an essay in the form of a ‘Preface’ that scanned recent developments around Darwin's writing. For this third edition I have added the essay ‘Darwin and the Consciousness of Others’. This relates Darwin's early thinking in the 1830s to his much later work such as The Descent of Man (1871) and Expression of the Emotions (1872). The topic is Darwin's abiding fascination with forms of consciousness in other organic life and his interest in the reasoning processes of infants and of other human cultures. That essay can be found at the end of this volume together with a further reading list.

I am grateful to the Vice-Chancellor of the University of Oxford who invited me to give the Romanes Lecture, 2007, the occasion of this essay, and to the Librarian of Bodley, where a copy of the essay has been deposited. I am grateful, as always, to my family and friends for their stimulating conversations and, particularly in this instance, to Linda Bree of Cambridge University Press with whom I have long collaborated and who encouraged this third edition.