In order to clarifing the pathways of epileptic convulsion, the following experiments were performed by the author. The same fieldes in the diencephalon of the cat were selectively damaged with the Horsley-Clarke's stereotaxic apparatus, and I-3 weeks after the operation the animals were artifically convulsed with the injection of 10% cardiazol into the cerebral cortex. The resultes were as followes: 1) By the damaging the bilateral Forel's field, the epileplic convulsion was efficiently intercepted, namely, among the 25 operated animals the 23 cases had no convulsion by a cardiazol injection, and only 3 convulsed. 2) By the large damaging on the bilateral nucleus of the thalamus, epileptic convulsion was also intercepted, namely, among the...