Based on a survery of the literature and his own publications the author maintains that hypo- as well as hyperpituitarism do not cause simple micro- or macrosplanchnia but a characteristic pattern of dystrophy in various organs and tissues. The islet organ shows a hypertrophic tendency in hypo-, atrophic in hyperpituitarism. The metabolism of carbohydrates behaves correspondingly. Cases of insuloma of the pancreas combined with lesions of the anterior pituitary are discussed in this connection.