The case herewith reported throws some light on the pathology and treatment of a lesion of the epiphysis of the femur in the young, the exact nature and proper therapeutics of which have been the subject of much recent discussion. REPORT OF CASE History.—C. P., a boy, aged 10 years, who entered the Presbyterian Hospital, March 1, 1920, complained of limited motion in the right hip; this had begun five months previously with pain in the hip and a slight limp. The pain, which was of a dull, aching character, was worse in the daytime. He was not confined to bed and had no constitutional symptoms. A physician had been called three weeks after the onset of symptoms, whereupon the patient was put to bed for three months, with the leg maintained in extension by weights. The pain disappeared and had not returned in the last six weeks, during