ABSTRACT
The widespread occurrence of the demyelinating diseases of the central nervous system makes the study of the events that accompany normal myelin formation one of major significance in neuropathology. In the latter part of the last century the earlier stages in the development of the nervous system in embryos were studied in detail by many investigators, but since then, in spite of its evident importance, this aspect of embryogenesis has attracted little attention from embryologists and neurohistologists. In view of the advances now being made in the chemistry of the nervous system, the time seems opportune to return to the problem of myelinogenesis with the hope of bringing together some of the many important relevant observations in neural morphology and biochemistry.