SOME LIMITATIONS OF THE MONRO-KELLIE HYPOTHESIS

For almost a century and a half, the hypothesis that the skull and bony coverings of the vertebral canal form a rigid container for the central nervous system has occupied the attention of anatomists, physiologists and neurologists. It is a hypothesis which has been gradually changed in its scope, and even in its conception, since its original promulgation by Alexander Monro¹ in 1783. Having been of interest to many in the course of the first fifty years of its existence, the doctrine has, in the past three decades, again become the subject of intensive investigation by workers in intracranial physiology. It is a tenet which has particularly concerned neurologic surgeons, because on its truth, or relative untruth, depend many of the critical procedures in the surgery of the central nervous system. The doctrine has especially intrigued the scientific curiosity of Harvey Cushing, to whom the academic world owes a