How would you like that symbol, doc? One snake or two?

On Jan. 25, a drawing in Science Times showed a patient borne aloft by the caduceus -- the wand of the Greek god Hermes, or Mercury to the Romans, entwined by two snakes and topped by wings.

That irritated a reader, Dr. Charles K. Tashima, who wrote that using the caduceus as a symbol of medicine is a "grievous error."

The proper symbol, regardless of what the dictionaries say and what can be seen flapping on many doctors' coats and letterheads, is the staff of Asclepius, or the Asklepian, which is a stout club with one snake and no wings.

And thus was opened a can of wriggly things.

This debate, which has the Japanese-horror-movie name "the caduceus versus the Asklepian," has played out on the pages of medical journals for years. The view of most medical historians is that the Asklepian is correct, but doctors -- American doctors in particular -- have made the same error for so long that the wrong answer has become the standard, like the Battle of Bunker Hill, which was actually fought on nearby Breed's Hill.