Lit review for my Archetypes of Cyberspace essay:
This is a nice image of the staff and makes me think of the sign for Mercury and is pertinent to the strange debate about the symbolism involved. Here is a link to a site that claims the caduceus is not the medical symbol at all.
In other words, the Caduceus was just the wand of a conniving god of thieves who helped folks to Hades, and had nothing to do with medicine, let alone healing.
More on that here. With a more traditional image of the caduceus:
Ginette Paris argues more convincingly for two medicines that need clarifying: Hermes and Apollonian.
Interesting too is the link between Hermes and the later Hermes Trismegistus, here is a page light & clear.