In recent years the problem of epilepsy has been examined with intensified interest in the experimental laboratory. One technique that has been employed is the initiation of after-discharge by direct stimulation of a cortical locus or nuclear mass in the brain. As this procedure is one which has been utilized clinically,9,10 experimental data derived from its use would seem to be unusually applicable to the problem of seizures in man.
It was found in a previous study that different regions in the monkey cortex varied in the capacity to exhibit after-discharge when stimulated.6 These observations indicated that a portion of the motor cortex was the most epileptogenic region on the hemisphere and that this locus responded to low-voltage stimulation by initiating diffuse seizures. Studies in the cat, however, revealed that the motor cortex was far less excitable than in the monkey,1 it being impossible, occasionally, to elicit