This disease is a rare one, and, as the symptoms closely resemble those of multiple neuritis, the discrimination of cases is not easy. The principal feature is the occurrence, with little or no disturbance of the general health, of a motor paralysis, extending, in the course of a few days or weeks, to the entire lower limbs and then rapidly to the upper. It rarely takes the opposite course. The muscles become slack and soft and lose their reflex irritability, and they rapidly atrophy. There have been few postmortem examinations, but they seem to show a chronic inflammation or sclerosis of the anterior cornua with loss of the ganglion cells. The disease is frequently recovered from, but recovery is slow, and complete restitution may take years. On the other hand, the disease may extend upwards and produce death.