History. —Mrs. R., aged 36, Feb. 28, 1910, fell down-stairs and in some way hurt her left wrist. She immediately came to my office three blocks distant. Walking into the consultation room she held out her forearm in medium pronation, the hand and fingers slightly flexed. the patient thinks now that the hand was somewhat drawn to the ulnar side. I noticed an abnormal protuberance on the dorsum of wrist and made a hasty (before examination) diagnosis of Colles' fracture. Examination and Treatment —I examined the wrist and soon discovered that there was not a Colles' fracture; now could I make out any fracture, except possibly one of the ulnar styloid. It was discovered that the ulna was dislocated forward and that it was easily reduced, but that when the pressure which was needed to reduce it was released, dislocation recurred. Motion in all directions was somewhat limited