The type of neuritis which is the subject of this paper is peculiar, in that it develops many years after fractures and dislocations about the elbow joint. For this reason it has been termed "tardy" or "late" paralysis. Usually, the injury to the joint has been received in childhood, the first symptoms of ulnar neuritis making their appearance in adult life. Thus, an interval which may vary from six to thirty-five years elapses between the initial injury and the first symptoms of ulnar neuritis, which are then gradually progressive. This remarkably long latent period excludes the group of cases, not uncommon, in which secondary paralysis follows redundant callus formation, vicious union, or other mechanical complications of fracture which jeopardize the integrity of neighboring nerve structures. The curious, and at the same time characteristic, feature of the late paralysis is its appearance so long after reception of the original injury that