Caduceus as a symbol of medicine worth noting that hospital stewards were not physicians; they played a supporting role preparing drugs for surgeons, supervising nurses and cooks, maintaining accounting and medical records, and in emergencies sometimes performed minor surgery or provided prescriptions. Later, in 1871, the Surgeon General designated the caduceus as the seal of the Marine Hospital Service (destined to become the U.S. Public Health Service in 1912). Gershen states that the change was for aesthetic reasons, whereas Friedlander states the caduceus was adopted by the Marine Hospital Service "because of its relationship with merchant seamen and the maritime industry". The caduceus was formally adopted
Saint George and the Dragon century show military saints on horseback confronting serpents with one, two or three heads. One of the earliest examples is from the chruch known as Mavrucan 3 (), generally dated to the 10th century, which portrays two "sacred riders" confronting two serpents twined around a tree, in a striking parallel to the Dioskuroi stela, except that the riders are now attacking the snake in the "tree of life" instead of a boar. In this example, at least, there appear to be two snakes with separate heads, but other examples of 10th-century Cappadocia show polycephalous snakes. A poorly preserved wall-painting at