In his seventeenth year, the boy had been taken with a severe attack of what was regarded as an “attack of indigestion.” This attack ushered in a gradually developing muscular weakness, especially involving the limbs. By the age of 21 he had become irritable and the paresis was so extreme that the patient was unable to get in or out of a carriage. This generalized muscular weakness was plain upon admission to the hospital though there seemed to be no actual paralysis. The patient was unable to walk in a straight line and Romberg’s position could not be maintained. Marked tremor was present in the hands and lips. There was bilateral impairment of vision and nystagmus. Reflexes and sensations normal. Speech was markedly affected, all syllables being very much slurred. School knowledge and memory for both recent and remote events very poor. The patient’s habits were very untidy. He was very emotional, easily made to laugh or cry; and in behavior, extremely childish. Two months after his admission to the hospital, the weakness suddenly became extreme. He was constantly nauseated, refusing food. The face and hands were cyanosed and the heart’s action rapid, weak, and irregular. This attack lasted for a week and was followed by a period of improvement, during which, however, he still remained very weak and apathetic. One month later he again became so feeble that he was unable to raise himself in bed. He complained persistently of feeling very “sick.” His temperature was elevated and there occurred the same train of circulatory symptoms observed previously, _viz._, rapid and tumultuous action of the heart, with cyanosis of face and extremities. He soon became unconscious, remaining so until his death, which occurred on the seventh day of the acute attack. This case was under observation before the days of the W. R., yet clinically the case had been diagnosticated JUVENILE PARESIS. There was no history of the acquisition of syphilis or any likelihood of its acquisition. Considered clinically, many of the classical features described by Addison were present, _viz._, marked asthenia and apathy; severe and frequent gastro-intestinal symptoms (the disease probably commencing with the attack of so-called “acute indigestion” six years prior to patient’s death); attacks of extreme cardiac weakness with the characteristic small, low-pressure pulse. On the other hand, pigmentation of the skin (usually the most striking clinical feature) was limited to the external genitalia, these being colored a deep brown.