Herophilus (335–280 b.c.) is usually credited with recognition of the human cerebellum as a distinct division of the brain. Aristotle (384–322 b.c.), however, calls it parencephalis, indicating that he did not regard it as part of the principal mass of the brain. The great Galen (a.d. 131–200) designated the vermis cerebelli “the worm-like outgrowth” (epiphysis scolexoides). The arbor vitae [the treelike set of outlines of white substance seen on a median section of the cerebellum] was described by Thomas Willis (1664) in his Cerebri Anatome as “ramificatio cerebelli ad foramen arboris.” The latter author also suggested that the cerebellum presides over the involuntary movement of the body, whereas the cerebrum controls those movements brought about by volition. The first good drawing of the vermis was publishes by Heister (1717), but Vesalius (1543) had already included in his Fabrica rather crude illustrations of the entire cerebellum which are in striking contrast to his beautiful figures of muscles, bones, and other structures. Haller (1777) described the cerebellar hemispheres under the name lobi, and Malacarne (1780) gave a detailed description of the entire organ. Many of the terms which Malacarne introduced are still in use. He also described the surface folia or “laminette,” giving their total number as 500 to 780.[…]