An attempt is made to describe the vascular architecture of the cortex employing a stereological method. Brains perfused with India ink were sectioned in frontal, sagittal and tangential levels. The course of the vessels was described as a spatial vector from the center to the penetration point of the globe of radius 1. In order to present a two-dimensional image, we projected the penetration point together with the longitudinal and horizontal meridians of the globe in an orthograde fashion into the level of the image. The frontal and sagittal sections were projected in an equatorial image, the tangential level was projected to an axis. Direct observations and stereological imaging demonstrated that, in lamina 4, there is a relatively constant hexagonal vascular net with branching angles of 60° at an edge length of 50–60 µ