The pathology of this case is very obscure. The contraction evidently depended upon a trophic lesion, perhaps due to the injury in childhood, involving the ulnar portion of the flexor profundus, impeding the growth of the muscle, and so preventing it from keeping pace with the normal growth of the bone, but not causing paralysis. The contraction of the flexor sublimis was evidently secondary. The recurrence of the deformity may be explained by the progressively increasing length of the bones of the forearm, the muscle remaining stationary; in other words, the original cause of the condition—the incapacity of the profundus for development—persisted, and led to a return of the effect. Under these circumstances it would obviously be advisable to delay a second operation until the osseous system had reached its permanent proportions. The operation I believe to be original; and so far as the restoration of continuity of tendon is concerned, the result proved a complete success. It might possibly be applied with advantage in various conditions as a substitute for tenotomy. The operation was performed independently by Professor Keen,[3] about a twelvemonth after this case, and has since been adapted to lengthening and shortening of tendons by Drs. H. A. Wilson,[4] Colgan,[5] and Ochsner, in America. CASE 2.—H. L., a youth aged seventeen, was admitted as an out-patient at St. Thomas’s Hospital, in November 1890. He complained of a contraction of the thumb and fingers of the right hand of three years’ duration. The condition began without apparent cause, and has increased progressively. He was fairly well grown, but of somewhat delicate aspect. He had an attack of rheumatic fever at the age of six, but had since been in good health. The contraction was of the same nature as that in Case 1, but less in degree, and involved all the digits. The hand was well formed, and all the bones, joints, and muscles were normal. The power of finger extension was complete during flexion of the wrist. The forearm flexors are rather small, but there is no distinct atrophy; the movements at the wrist, elbow, and shoulder are perfect. He said that the defect crippled him greatly for work, and that forcible extension caused pain in the forearm. He was instructed to carry out a system of massage, with active and passive movements of the fingers and wrist. CONTRACTIONS DUE TO UNBALANCED ACTION OF THE FLEXOR MUSCLES AFTER RUPTURE, DIVISION, OR DESTRUCTION OF THE EXTENSOR TENDON.