The work of Oppenheim1and of Henneberg2in rewriting the chapter on myelitis was a welcome, although not an unopposed, forward step in the understanding of diseases of the spinal cord. Today the terrain of myelitis, although more sharply limited, still requires study to determine the grouping of various clinicopathologic syndromes which have been described under various headings. In this study we are concerned with what appears to be an entity that is best described under the heading of progressive necrosis of the spinal cord. The term myelomalacia has been employed to describe this condition by Schmitt3and others. This term would be desirable, but, owing to its usage since the time of Westphal4in 1874 in association with softening secondary to vascular lesions, it can scarcely be employed in this connection without causing added confusion. Progressive necrosis of the spinal cord may appear to be