Roussp ('07) was among the first to study thalamo-cortical fibers in the monkey. He described fibers going from the lateral nucleus to the parietal and posterior frontal region. Sachs ( '09) produced lesions in the thalamus and studied the ensuing degenerated tracts by Marchi staining. IIe found that the anterior portion of the lateral nucleus had efferent connections with the superior frontal and precentral gyri, while the ventral nucleus had connections only with the prea i d postcentral gyri, He further found a dorsoventral topowaphical arrangement of the thalaino-cortical fibers ; those from the most dorsal part of the lateral nucleus extended to the leg. area of the cortex and those from the most ventral part, or lower ventral nucleus, extended to the opercular area. Other connections of the lateral nuclei were short fibers to the adjacent regions of the thalamus.
Minkomsky ( '23) studied the thalamo-cortical connections of the monkey bjremoving portions of the cerebral cortex and later studying cellular degenerations in the thalamus. He concluded that the lateral nucleus had the following connections : The posterior extremity with the superior parietal This investigation has been aided by a grant from the Committee on Scientific Research of the American Medical Association.