Caduceus (4 syl.). A white wand carried by Roman officers when they went to treat for peace. The
Egyptians adorned the rod with a male and female serpent twisted about it, and kissing each other. From
this use of the rod, it became the symbol of eloquence and also of office. In mythology, a caduceus with
wings is placed in the hands of Mercury, the herald of the gods; and the poets feign that he could
therewith give sleep to whomsoever he chose; wherefore Milton styles it “his opiate rod” in Paradise
Lost, xi. 133.

I have read that the US Army Medical Corps errs in using as its symbol a caduceus with two snakes.
The caduceus of Aesclapius the god of healing had only one snake, and is the symbol used by the
British military medical officers. I'm sure they prized the authenticity of their insignia, vs. poor
scholarship behind selection of the American one.