Two Serpents or One, the Real Story
Two snakes or one? By tradition, the medical profession has been recognized by the caduceus symbol - a crude stick or staff intertwined with two serpents. The authentic caduceus, however, is entwined with only a single serpent. There is an appropriate, though little known, reason behind this distinction.
In Greek and Roman mythology, the gods Hermes and Mercury carried a staff with two serpents. These two gods are described respectively as the 'conductor of souls to Hades' and the god of commerce and thieves. In contrast, the Roman god of healing, Aesculapius, carried a staff with a single snake. Snakes were sacred to Aesculapius because it was believed that they could renew their youth by shedding their old skin and growing a new one.
Historically, D.O.s have chosen to identify with the healing symbolism of Aesculapius' single snake emblem rather than the images portrayed by the patrons of the two-serpent version. NOTE: The addition of wings to either staff acknowledges medical personnel with military status.