Thomas Willis, Opera Omnia.
Nearly a century later, in 1664, the English physician Thomas Willis (1621-1775) wrote Anatomy of the Brain and Nerves, which was translated into English in 1681. This work made a huge impact on the medical establishment, with minute and elaborate descriptions far surpassing anything previously published. Illustrated here is the Circle of Willis (also called the cerebral arterial circle, or circulus arteriosus cerebri) which is a circle of arteries that supply the brain with blood. The arrangement of the brain's arteries into the Circle of Willis ensures cerebral circulation is maintained should one of the arteries in the circle become blocked or narrowed. The Anatomy of the Brain and the larger Opera (Works) would have been key texts for Secundus.
Thomas Willis, Opera Omnia. Amsterdam: H. Wetstenium, 1682.