Well, Shinobi and Bro. Madore, this brings us to our old friend, Albert Pike, about whom we had a discussion a few days ago.
Pike mentions the caduceus in Chapt. 25 of Morals and Dogma, which discusses the 25th Degree of the AASR, Knight of the Brazen Serpent. (The Brazen Serpent refers to an incident recorded in the book of Exodus. In the Northern Jurisdiction, this incident is portrayed in the 25th Degree. The Southern Jurisdiction ritual, written by Pike, is more concerned with astronomy and ancient religious beliefs.)
Pike says, “The Caduceus, borne by Hermes [Trismegistus] or Mercury, ... was a winged wand, entwined by two serpents.” He then relates it to the Crux Ansata and to the Tau cross and by extension to the Tau. The Tau is an important symbol in both the AASR and the York Rite (the triple Tau is an important symbol in the Royal Arch).
I don’t recommend dredging through M&D to see what Pike has to say there. It’s one of the longest and most tedious chapters in the book.