Robert J. Bradbury wrote:
> A few years ago, I seem to recall an article about a
> scientist discovering a branch of fungi which had
> a dozen or more "sexes".
> Why do we have to confine ourselves to perspectives
> "tainted" by the genetic tree we happen to currently
> be in?
I'd go for four different 'sexes' - the equivalent of Penrose tiles, then we can engage in non-periodic relationships.