The only adjective which Celsus applied to headache was "intolerabilis." Unless it was intolerable, he said, there was no necessity for a remedy (Vaughan, 18251). Today the same proviso might be applied, at least to surgical remedies. But when the ache is intolerable, radical operative treatment should be undertaken. Knowledge of the innervation and sensitivity of intracranial structures is prerequisite to success with such treatment. This study is concerned primarily with the nerve supply and pain reference of the dura mater in man and in the monkey. It is illustrated by clinical cases which cast light on dural sensitivity and on the radical treatment of falcial cicatrix, migraine and other forms of headache. A preliminary anatomic study has already been published by one of us (F. M.).2
STRUCTURE AND DEVELOPMENT OF THE CEREBRAL DURA MATER
The cerebral dura is a very tough membrane composed of two closely adherent