The writer regards all convulsions accompanied by unconsciousness as symptoms of some underlying state or disease, and he believes that epilepsy is an organic condition due to definite pathologic cerebral tissue changes. Morbid conditions of the pituitary gland are found in a number of cases causing a change in its secretion. The investigation of 200 cases of epilepsy by roentgenographic examinations revealed some evidence of pituitary disturbance in 31·5 per cent. Some of these showed evidence of syphilis or other disorders and 14 per cent. were regarded as pure pituitary cases. From his observations the writer concludes that there is a definite relation between the undersecretion of the pituitary gland and a group of convulsive attacks usually termed epilepsy; that this group is divided into a chronic hypopituitary type and a transitional hypopituitary type by both clinical and roentgenographic evidence; and that pituitary gland feeding has a markedly beneficial effect, not infrequently leading to a cure.