Just as background for those (like myself) lacking any significant knowledge of mythology ... (with thanks to Wikipedia and other sources) ....
In Greek mythology, the Rod of Asclepius, also known as the Staff of Aesculapius and as the asklepian, is a serpent-entwined rod wielded by the Greek god Asclepius, a deity associated with healing and medicine.
The caduceus is the staff carried by Hermes in Greek mythology and consequently by Hermes Trismegistus in Greco-Egyptian mythology. The same staff was also borne by heralds in general, for example by Iris, the messenger of Hera. It is a short staff entwined by two serpents, sometimes surmounted by wings.
Hermes was the ancient
Greek god of
trade, wealth, luck, fertility,
animal husbandry, sleep, language, THIEVES, and travel. One of the cleverest and most MISCHIEVOUS of the Olympian gods, he was the patron of shepherds, invented the
lyre, and was, above all, the herald and messenger of Mt. Olympus so that he came to symbolise the crossing of boundaries in his role as a guide between the two realms of gods and humanity. To the Romans, Hermes was known as Mercury, also associated with speed, which is why the innermost and fastest planet in our solar system is named Mercury.
His attributes and symbols include the herma, the rooster, the tortoise, satchel or pouch, winged sandals, and winged cap. His main symbol is the Greek kerykeion or Latin
caduceus in the form of two snakes wrapped around a winged staff with carvings of the other gods.
The references to thieves and mischief are puzzling, given the association of the symbology with medical practice.
So ... in spite of that little bit of puzzlement ... there is lots to be learned from pen-making ! . And, the learning doesn't stop there .... !!
For further study, check out herma.