It is estimated that the functionally significant body of knowledge for a given medical specialty changes radically every 8 years. New specialties and "e;sub- specialization"e; are occurring at approximately an equal rate. Historically, estab- lished journals have not been able either to absorb this increase in publishable material or to extend their readership to the new specialists. International and national meetings, symposia and seminars, workshops and newsletters success- fully bring to the attention of physicians within developing specialties what is occurring, but generally only in demonstration form without providing historical perspective, pathoanatomical correlates, or extensive discussion. Page and time limitations oblige the authors to present only the essence of their material. Pediatric neurosurgery is an example of a specialty that has developed during the past 15 years. Over this period, neurosurgeons have obtained special train- ing in pediatric neurosurgery, and then dedicated themselves primarily to its practice. Centers, Chairs, and educational programs have been established as groups of neurosurgeons in different countries throughout the world organized themselves respectively into national and international societies for pediatric neurosurgery. These events were both preceded and followed by specialized courses, national and international journals, and ever-increasing clinical and investigative studies into all aspects of surgically treatable diseases of the child's nervous system.

It is estimated that the functionally significant body of knowledge for a given medical specialty changes radically every 8 years. New specialties and "e;sub- specialization"e; are occurring at approximately an equal rate. Historically, estab- lished journals have not been able either to absorb this increase in publishable material or to extend their readership to the new specialists. International and national meetings, symposia and seminars, workshops and newsletters success- fully bring to the attention of physicians within developing specialties what is occurring, but generally only in demonstration form without providing historical perspective, pathoanatomical correlates, or extensive discussion. Page and time limitations oblige the authors to present only the essence of their material. Pediatric neurosurgery is an example of a specialty that has developed during the past 15 years. Over this period, neurosurgeons have obtained special train- ing in pediatric neurosurgery, and then dedicated themselves primarily to its practice. Centers, Chairs, and educational programs have been established as groups of neurosurgeons in different countries throughout the world organized themselves respectively into national and international societies for pediatric neurosurgery. These events were both preceded and followed by specialized courses, national and international journals, and ever-increasing clinical and investigative studies into all aspects of surgically treatable diseases of the child's nervous system.