The dura mater, the mother membrane of the body according to the ancients, is a much neglected and most important organ, for organ it must be regarded in the human anatomy. To the average student and general practitioner the dura is but a tough inelastic, fibrous membrane of unusual thickness, which plays the part of a scaffolding and support for the brain.
A careful study of this part, however, shows that it is not only the superstructure upon and in which the brain is built, but that it is an internal periosteum to the skull‐a complex channel for the great venous currents through which course, not only the venous blood from the brain, but much from outside the skull,‐likewise a soft, serous cover for the membranes of the convolutions and sheath for the cranial nerves. It has, furthermore, a small arterial supply, which is gathered from branches of both the