The time-honored custom of subdividing the brain into lobes for physiologic study is still in vogue, notwithstanding the work of Brodmann, who showed that the homology of regions of the brain in man and animal does not follow the topography marked out by the sulci. There can be little doubt that in the future the study of the physiology of the brain according to lobes will be superseded by a more scientific modus. The frontal lobe is a large area of the brain; it is not a single mechanism with a single function. Hence, the tendency in neurology to formulate "syndromes," a group of symptoms all present or absent in a certain disease, is of questionable value here. To draw conclusions concerning the physiology and physiologic pathology of this region of the brain from symptoms observed when tumors involve the frontal lobe is fallacious, since the clinical picture is constantly