Touch and surgical division of the anterior quadrant of the spinal cord. An investigation was carried out to determine whether tactile sensibility was affected by anterolateral cordotomy. There were 65 patients who had cordotomies for painful forms of cancer. Thirty eight had necropsy examination with histological investigation of the spinal cord. No form of mechanoreception was removed in any of the 65 patients and in the majority no forms of tactile sensibility were altered by division of the pathways in the anterolateral and anterior columns. In no case was graphaesthesia affected. Knowledge of joint position and movement and awareness of vibration was normal in 62 of the 65 patients. But information carried by these anterolateral pathways does reach neural levels of consciousness, for with total lesions of the posterior columns, previously reported, touch and pressure are still felt. Itch was removed by division of the anterolateral pathways. Although the posterior columns are essential for discrimination in mechanoreception, discrimination may be disturbed by lesions of the anterolateral pathways, notably two-point discrimination. The evidence on the pathways essential for conveying impulses giving rise to tickle was inconclusive. 