My attention was especially called to this rare condition by two cases observed and studied. At the time, I supposed it was an exceedingly rare complication of early syphilis, and this idea was rather confirmed by questioning colleagues as to their experience. However, I was surprised indeed on looking up the literature to see that it is by no means an uncommon condition, and we must now add our affirmation to that of Kuh,1 page 386, "If one studies the literature one can hardly draw any other conclusion than that the importance of syphilis in the etiology, not only of acute myelitis but also of chronic myelitis, has been underestimated." Quite early, Ricord,2 Caizergue,2 Juillard2 and others described this condition. Euhlenberg,2 Fournier,2 Erb,3 Gowers4 and other authors have also written quite extensively on the subject. Leyden,5 in 1874, reported cases presenting