Villus Vidius, the Latinized name of Guido Guidi, an Italian physician, born in Florence about 1500, died in Pisa, May 26, 1569. Early in life he was called to France, where he was appointed first physician to Francis I., and acquired great reputation both as a practitioner and as a lecturer. After the death of Francis I. he returned to Italy, where he became physician to Cosmo de' Medici, a member of the Florentine academy, and finally professor of medicine in the university of Pisa. His name is perpetuated in the anatomical designation of the Vidian nerve, a filament running from the spheno-palatine ganglion of the sympathetic at the base of the skull, backward through a special canal in the pterygoid bone, and connected by a double branch with the petrous portion of the facial nerve and the carotid plexus of the sympathetic. Vidius published many works on the institutes of medicine, hygiene, therapeutics, fevers, aliment, materia medica, and anatomy. They were all collected by his nephew of the same name, physician to the queen of France (3 vols., Venice, 1614).