OBSERVATIONS ON THE HISTORY OF THE `CIRCLE OF WILLIS'

Abstract

THE term 'Circle of Willis' has been accepted for the characteristic arterial ramifications at the base of the brain, and widely used for about two hundred years. In truth, it is not a circle but an angular seven-sided structure termed 'heptagon' by Italian and some French writers. Moreover, Thomas Willis, who illustrated the 'circle' in his book Cerebri Anatome in I664, was not the first to describe this structure. During the subsequent centuries there were some who recognized this, as we shall see presently, but to the majority Willis's priority was and still is widely accepted without further discussion. Among the most commonly used modem textbooks of the history of medicine in the English language, only Mettler (I947) and Cole (I944) squarely deny Willis's priority; Garrison (1929), Castiglioni (I 958) and Major (I 954), however, do not question it. Singer (I957) does not bring his history of anatomy as far as the time of Willis, but he seems to accept the circle ofWillis without reservation. In the case of Castiglioni, this omission is unexpected, as in the discovery of the circulation of the blood he appeared to divert to some degree, the glory from Harvey (whose pre-eminent part he frankly accepts) towards Harvey's Italian precursors Servetus, Columbus and Cesalpino.