The "septum pellucidum" has been described since antiquity. Even though people such as Vicq d' Azyr (12) and Burdach (3) pictured the septal region in their drawings, the nuclei associa- ted with the pellucidum--the septal nuclei--were not described until Meynert (10). Since Meynert's description, this portion of the limbic system has been troublesome in terms of nomenclature. Scientists about the turn of the twentieth century proposed quite diverse termin- ologies. For example, Elliot Smith first wrote of the precommis- sural area (4) and then later of the paraterminal body (5). These terms,...