A new heterotopic callosal projection of primary visual cortex in the monkey, Callithrix jacchus.

A callosal projection of area 17 upon the dorsomedial visual area in the marmoset monkey was demonstrated by means of retrograde transport of neuronal tracers. The projection was restricted to those regions representing the vertical meridian in the two areas. This finding, and the data of other authors, indicate that the monkey area 17 projects transcallosally onto homotopic and several heterotopic targets.