Constantio Varoli (1543-1575) of Bologna, was an important figure in the history of the science of human anatomy. Though he died at the early age of thirty-two, he acquired a reputation equal to that of the most eminent of his contemporaries. He is now known chiefly as the author of an epistle, inscribed to Hieronymo Mercuriali, on the optic nerves, in which he describes a new method of dissecting the brain, and communicates many interesting particulars relating to the anatomy of the organ. He observes the threefold division of the inferior surface or base, defines the limits of the anterior, middle and posterior eminences, as marked by the compartments of the skull, and justly remarks that the cerebral cavities are capacious, communicate with each other, extending first backward and then forward, near the angle of the pyramidal portion of the temporal bone, and that they are folded on themselves, and finally lost above the middle and inferior eminence of the brain. He appears to have been aware that at this point they communicate with the exterior or convoluted surface. He recognized the impropriety of the term corpus callosum, seems to have known the communication called afterwards foramen Monroianum, and describes the hippocampus more minutely than had been previously done.