Figure 3. Drawings by Leonardo da Vinci (1508-1509) taken from the Codici di Anatomia of the Windsor’s Collection (Courtesy of the Library of the Department of Human Anatomy of the University of Parma, Italy). (A) Inferior surface of the brain, showing the rete mirabilis (arrow) that surrounds the pituitary gland; (B) three-dimensional representation of the cerebral ventricles. The third ventricle (3v) was believed to be the site of afference and elaboration of the “sensus communis” (Latin for peripheral physical sensations). (From Toni R, Malaguti A, Benfenati F, Martini L: The human hypothalamus: a morphofunctional perspective. J Endocrinol Invest 27 (supp to n.6), 73-94, 2004.)