The blood supply of the corpus callosum is studied in 20 brains by injecting the vascular system with gelatinous Indian ink. The arterial vascularization derives mainly from the anterior cerebral arteries, accessorily from the median artery of the corpus callosum or from the terminal and choroidal branches of the posterior cerebral arteries. The various arteries give off perforating branches which are direct or indirect, short, of middle length or long. All these arteries concentrate on the peripheral wall of the corpus callosum. Inside of it these various arteries give off numerous terminal and collateral branches running between the nervous fibres and forming a characteristic vascular network which nourishes the capillary network. The venous vascularization of the corpus callosum is tributary to the deep venous system of the brain and concentrates on the central wall of the commissure.