Its first description is traditionally taken to be in 1641, possibly by Caspar Bartholin, where its discovery was attributed to Franciscus Sylvius (1614–1672), professor of medicine at Leiden University in the book "Casp. Bartolini Institutiones Anatomicae" where it is noted that "F.S. probably refers to Franciscus Sylvius If you examine the indentations which are represented in Figure 5 quite attentively, you will notice that they are very deep and that the brain is divided from one side to the other by the 'anfractuosa fissura,' which starts in the front part near the ocular roots, and from there moves backwards above the base of the spinal cord, following the temporal bones, and it divides the upper part of the brain from the lower."