In the course of postmeasles encephalomyelitis, neurologic and mental disturbances resulting in permanent organic defective states may occur. Ford1 in reviewing 125 cases, including 12 of his own, found such residual symptoms in 65 per cent of patients who survived. The pathologic conditions underlying such organic disturbances have so far not been described, except for a few doubtful cases, which I shall discuss later. It is the purpose of this contribution to report 2 cases which illustrate clinically and pathoanatomically the sequelae of postmeasles encephalomyelitis and to trace the manner in which this terminal condition develops from the preceding acute and subacute stages, which have been outlined in a previous communication.2 Such an investigation may also be of value in differentiating disseminated encephalomyelitis from multiple and diffuse sclerosis, concerning which there is considerable confusion in the literature. REPORT OF CASES Case 1. —E. T., a white boy aged