Historical accuracy has been sacrificed to enable the telling of several layers of story. It's also a rhyme that I've carried with me from childhood. I used to wonder. I instinctively knew, even as a very young child that the mood in that scene was dark and erotic. Much of the way in which I respond to this rhyme is emotional and intuitive.
Reason takes a second place.
For me this is the best kind of material to work with. It doesn't pay to think about things too much when you are involved on a project. It is easy to kill. I sat down one day and the concept for the book tumbled out in story board form in the space of a couple of hours. Very few changes, and no major ones, were made to it at all.