CASE 1.—M. O., a domestic servant aged seventeen, was admitted into St. Thomas’s Hospital in September 1889. On examination the third, fourth, and fifth fingers of the right hand were found to be flexed at the metacarpo-phalangeal and inter-phalangeal joints—the two latter strongly, the former slightly. When the wrist was fully extended the contraction became more marked, and the distal phalanges of the ring and little fingers touched the palm, but when the wrist was fully flexed the fingers could be voluntarily brought into a state of complete extension. The power of grasp was good, although somewhat less than in the left arm; the bones were normal in form and size; and the joints were quite free in their movements when the flexors were relaxed by position. The forearm muscles appeared to be of normal size. A small scar was seen about two inches below the elbow, over the inner side of the front of the arm, the result of a fall thirteen years before. The patient was strong and healthy in appearance, and showed no sign of neurotic disorder. She had never suffered from rheumatism or any other severe illness, and the family history appeared to be good. She stated that the contraction began to appear in childhood, shortly after the injury to the arm, but that it had been making more rapid progress in the past eighteen months, during which she had been growing very quickly. After a fruitless attempt to improve the condition by passive motion and splint extension, neither of which was well borne, it was determined to lengthen the tendons by operation. On October 18, 1889, the patient was chloroformed, and it was observed that the deepest anæsthesia caused no relaxation of the contraction. A semicircular incision was made over the inner side of the front of the forearm just above the wrist, the convexity overlapping the tendon of the flexor carpi ulnaris, the horns reaching to a line midway between the radial and ulnar borders of the limb. The flap of integument and fascia was reflected towards the radial side, exposing the inner portion of the flexor sublimis. The tendon of this muscle going to the ring finger was then isolated, transfixed by a fine tenotomy knife, and split longitudinally for a distance of two inches. At each end of the fissure so made the tendon was divided in such a manner as to leave one-half of the split portion attached to the proximal, the other to the distal, end of the tendon. (Fig. 8.) The tendon, a very slender one, to the little finger was similarly treated. The effect of this measure upon the contraction was very slight. The portion of the flexor profundus common to the middle, ring, and little fingers was then drawn out and divided after the same method, and the section was followed by immediate and complete extension of the digits.