The title refers to the two different but synonymous longitudinal midbrain bundles, one of which had two names. Described as early as 1846 by Benedict Stilling, our medial longitudinal fasciculus was first called "acusticus," then "posterior," by Theodor Meynert in 1872. Many authorities in neurology continued to call it "posterior" well into the 20th century. When, in 1891, Heinrich Schütz described the other longitudinal bundle, the one which was to keep his name alive, he chose the word dorsal--"for brevity's sake." Here Ramón y Cajal's alternative suggestion of "peri-ependymal" (1904) failed to achieve popularity, not to speak of Theodor Ziehen's nubecula dorsalis (1913). It probably was Wilhelm His, Sr, who in 1895 first prescribed the change from "posterior" to "medial" for the benefit of the Basle Nomenclature and an end to the confusion.