Rothmann points out how important it is to surgeons that the localisation of lesions in the brain and spinal cord should be made with the utmost accuracy. In many cases diseases do not strike suddenly upon a nervous system previously intact. Often the circulation has been previously deranged by arterial sclerosis, which prepares the way for transitory hemiplegia or aphasia. Sometimes there is loss of function after central lesions, which disappears in longer or shorter time. Goltz and his followers have treated many effects following the extirpation of the whole or part of the cerebrum as due to what they call inhibition (Hemmung). Thus the functions of the spinal cord are much impaired after removal of the cerebral ganglia, or the lower portion of the cord loses its reflex function after section higher up, but after a while it again resumes its act$ibon.