The same month that Darwin published his monograph on reefs—May 1842—he sketched out for the first time his revolutionary ideas about evolution, or “transmutation,” as the phenomenon was referred to in his day. The sketch was written in pencil and, in the words of one of his biographers, amounted to “thirty-five folio pages of crabbed, elliptical scrawl.” Darwin stuck the essay in a drawer. In 1844, he expanded it to two hundred and thirty pages, only once again to hide the manuscript away.
