Symbols are the signatures of human endeavour. They are soundings of the past, statements of the present and signposts to the future. Medicine has its share of symbols. These once included the stethoscope, the white coat and the black bag; but the white coat has been shed, the black bag abandoned and technology stalks the stethoscope.

One symbol persisted — the snake-entwined staff of Asklepios, hero physician and mortal son of the Greek god Apollo, from whom he inherited his mythical healing powers. Not so long ago, this familiar emblem graced the cars of doctors. But with persistent raiding of their cars for drugs and other booty, the badge of Asklepios has also been abandoned.

Disappointing as these symbolic losses are, of further concern is the usurper in the New World — the "medical caduceus", the double-serpent staff with its surmounting wings.

In The symbol of modern medicine: why one snake is more than two, Robert Wilcox and Emma Whitman of Flinders University in South Australia trace the history of this modern interloper and argue that it is an utterly inappropriate symbol for the profession.

The "medical caduceus" is based on the ancient staff of Hermes, messenger of Zeus. Among other things, Hermes was the god of thieves, merchants and commerce. Mercury, Hermes' Roman counterpart, "was even more closely identified with commercial pursuits and was commonly depicted carrying a purse bulging with coins". In truth, Apollo judged Hermes to be "a schemer, subtle beyond all belief".

Some may argue that Hermes' staff is an inappropriate symbol for modern medicine. But, given medicine's current climate of corporatisation, commercialism and advertising, it may well be entirely apposite.