Introduction The major convulsions that may follow the abrupt withdrawal of excessive amounts of barbiturate from man, dog, and cat present an interesting problem in the experimental neurology of seizure mechanisms.1,2,4-8 On the basis of previous studies of this phenomenon it has been postulated that cerebral cortex participates in the seizure mechanism but that the latter may not originate there.2,3 Although it is possible that cerebral cortex is involved in the seizure mechanisms secondarily, it may still be necessary for a complete evolution of the phenomenon. Therefore, this study was initiated to determine whether decortication prior to progressive barbiturate intoxication would prevent the subsequent occurrence of barbiturate withdrawal convulsions. This report will also describe some other effects of ablating cerebral cortex on barbiturate intoxication and withdrawal in dogs. Methods The practical difficulties encountered during the prolonged postoperative maintenance and chronic intoxication of the decorticate dogs