Degeneration density and topography in the thalamus of the squirrel monkey was studied following lesions in the septal area, fornix, and cingulate gyrus. It was found that the hippocampus projects more fibers to the anteroventral nucleus of the thalamus and the cingulate gyrus projects fewer fibers to it than does the septal area. The septal fibers to the anteromedial nucleus were more marked than were its projections to the anteroventral nucleus. The hippocampus and cingulate gyrus did not show this preferential projection. The thalamus is a more prominent target of limbic connections than heretofore realized. They appear to quantitatively rival known limbic-hypothalamic pathways. Therefore, in order to understand the total influence of the limbic system on cerebral function, one must consider its effects on thalamic perceptive mechanisms as well as effects on the hypothalamus.