Galen’s theory that the sexual organs were related by analogy, converted into a mnemonic for medical students (as reproduced in Siddhartha Mukherjee’s The Gene). It will confirm everyone’s worst suspicions, but that can’t be helped.
Though they of different sexes be
Yet on the whole, they’re the same as we
For those that have the strictest searchers been
Find women are just men turned outside in.
Mukherjee adds the question: … what force was responsible for turning men “inside out,” or women “outside in,” like socks?