Charles Robert Darwin was born in 1809. His great book, the Origin of Species, was published in 1859, when he was fifty. He was to live another twenty-plus years, dying in 1882, by which time the Origin had gone through six editions and been extensively revised and rewritten. It used to be the case that it was the sixth edition of 1872 that was most frequently reproduced, but more recently scholars have insisted that the first edition is the really important one - we not only see Darwin’s thinking in its original form but the revisions today are often judged to have been made for less than worthy reasons (in the sense that the criticisms now no longer seem so forceful). It is therefore the first edition that will be the focus of this piece, and my question opening this volume is about its genesis, and the implications that this had for the actual book that Darwin produced. While I do not think that the Origin is a particularly mysterious book, I believe that there are aspects to it that are not quite as obvious as we today often assume.