Masthead for Plan for Health Kaiser Permanente member newsletter, 1956.
Quick — what’s the symbol commonly used to depict medical practice?
If you said 2 serpents wrapped around a winged staff, you would be right — and wrong.
The story of the symbol representing medical care is one of mistaken identity. In the United States, we usually think of the caduceus, 2 snakes twisted around a winged staff. Its origins go back to antiquity, where it was carried by the Greek god Hermes and represented commerce and negotiation. It was later appropriated by the Roman god Mercury. The caduceus never referred to medicine (or at least the essence of healing), but it looks very much like the Greek Rod of Asclepius (composed of a single snake and staff, no wings), which does. What happened?
It appears that when the U.S. Army Medical Corps developed their branch logo in 1902 they picked the wrong symbol, and it has permeated American medical graphics ever since.
Also see article on the Kaiser Permanente logo.