1. An apparatus was designed to determine the shearing strength of the upper tibial epiphysis in the rat. Observations were made with this instrumenton normal animals, on animals receiving growth-hormone, and on animals receiving oestrogen.

2. When the epiphysis separates from the diaphysis, the plane of cleavage is constant, passing through the third layer of the epiphysial plate.

3. Growth-hormone decreases and sex-hormone increases the shearing strength of the epiphysial plate. These changes are due to alterations produced by these two hormones in the thickness of the third layer of the epiphysial plate.

4. It is suggested that these findings may be of significance in providing an anatomical basis for slipping of the upper femoral epiphysis in man, especially when it is associated with the adiposo-genital syndrome or with rapid adolescent growth.

1. Serial arteriograms show not only the anatomical distribution of blood vessels but also the functional state and activity of the peripheral circulation. The technique is of value in the diagnosis of tumours of soft tissues and bone, and particularly in the differential diagnosis of bone tumours from chronic osteomyelitis. It may be used to assess the response of malignant bone tumours to treatment by irradiation.

2. In malignant bone tumours, serial arteriograms show irregular formation of new vessels of uniform diameter, "blood pools," and increased rapidity of flow from the arterial to the venous systems.

3. In osteoclastomas there is new vessel formation and an appearance of "blood pools," but less rapid filling of the veins. In simple tumours there is no new formation of vessels. The tumour itself is often relatively avascular.

4. In osteomyelitis there is no new formation of vessels but only dilatation of existing vessels. The vessels retain their orderly and regular arrangement of successive branches of gradually decreasing diameter.

1. Three cases of localised deposition of calcium salts deep to the origin of the common extensors of the forearm with acute symptoms clinically indistinguishable from "tennis elbow" are described.

2. Reports of nine similar cases have been found in the literature.

3. It is suggested that "tennis elbow" is caused by a lesion, probably an adventitial bursa, in the tissue space between the tendon of origin of the forearm extensors and the capsule of the radio-humeral joint; and that it is the sudden precipitation of calcium phosphate at this site which causes the lesion here described.

4. Acute calcification near the elbow joint is compared with the similar calcification which may occur in the insertion of the supraspinatus tendon.

5. Operative treatment is advised.

Five cases of fracture-separation of the proximal epiphysis of the humerus are recorded. A method of reduction and immobilisation is described, and the literature is reviewed.

1. It is possible that neonatal sciatic palsy occurs more often than is suggested by perusal of the literature: paralysis of a foot may easily be overlooked in the new-born infant; it may be regarded as a temporary paresis due to mild birth trauma; or in later months it may be attributed to poliomyelitis.

2. Eleven cases of neonatal sciatic palsy are reported. Autopsy in one suggested that the paralysis was due to direct pressure on the sciatic nerve before birth.

3. A hypothesis is advanced by which to explain how pressure on the nerve trunk may arise in utero.

1. One hundred cases of torticollis and 117 cases of sternomastoid tumour have been reviewed.

2. Congenital torticollis can be sub-divided into two groups: postural and muscular.

3. Congenital postural torticollis is present at birth; it is not associated with a sternomastoid tumour; it is transient in nature; and it does not require operation for its relief.

4. Congenital muscular torticollis is preceded by a sternomastoid tumour which is clinically evident in one-fifth of all cases.

5. The ischaemic theory of the causation of sternomastoid tumours is not supported by recent histological investigations. Some other cause, which probably is operative before birth, must be sought.

6. Four-fifths of all cases of sternomastoid tumours resolve spontaneously and leave no deformity. Excision of the tumour in infancy is therefore unjustifiable.

7. Open division of the muscle and of the cervical fascia in congenital muscular torticollis cures the deformity but leaves an unsightly scar.

8. Subcutaneous tenotomy can be relied upon to cure the deformity if post-operative treatment is carried out skilfully and assiduously over a prolonged period.

9. If complete correction is not gained at the time of subcutaneous tenotomy a better result can be assured by open division of the upper end of the muscle through an incision within the hair line.

The clinical and pathological features of a pedunculated tumour of the left foot in a woman aged eighty-three years are recorded. The tumour had been present for forty years. Histologically, its pleomorphic structure was that of the "mixed tumour" of salivary gland with predominance of the myo-epithelial element. Its origin from sweat-gland tissue is presumed.

1. Study of 200 cases investigated by pneumarthrography has shown that the introduction of air or oxygen into the knee joint is followed by a specific reaction characterised by transient localised eosinophilia in synovial membrane and synovial fluid.

2. Complications after meniscectomy seem to be more frequent when operation is performed during the phase of eosinophil reaction.

3. The significance of these observations has been discussed in relation to other causes ofeosinophilia and it is suggested that this method of local production of eosinophils may be of experimental importance.

1. Pain and pressure sensibility has been studied in the fibrous articular ligament and synovial membrane of the knee joint in normal human subjects and in patients subjected to arthrotomy under local anaesthesia.

2. The fibrous ligament was found to be a highly sensitive structure, containing many spots which give rise to sensations of pain or pressure when stimulated mechanically or chemically. Synovial membrane was found to be a relatively insensitive structure which only occasionally contains pain-sensitive spots.

3. Histological examination of articular capsule from the knee joints of normal and sympathectomised cats shows that articular ligaments have a rich nerve plexus and a variety of specialised and unspecialised nerve endings, most of which are somatic in origin. Synovial membrane contains a more delicate nerve network and also a variety of nerve endings, the majority of which are autonomic in origin. But a substantial number of somatic nerves enter the synovial membrane, some of which terminate in nerve loops, globular endings or simple unspecialised endings.

4. Histological examination of normal human articular capsule shows that its innervation closely resembles that of the cat, but no sympathectomised human material was examined.

5. The bearing of these findings on the symptomatology of joint disease is discussed briefly.

1. The movements of flexion and extension at the knee joint take place above the menisci; the movements of rotation take place below the menisci.

2. The popliteus muscle consists of two halves, one being attached by tendon to the femur, the other by aponeurosis to the lateral meniscus. The action of the muscle is to rotate the knee and retract the posterior arch of the lateral meniscus. The flexing action of the muscle is quite negligible.

3. The effects of rotation of the knee joint on the two menisci are dissimilar. The medial meniscus is distorted during rotation; its horns move with the tibia, but the intervening arch moves with the femur, and the distortion renders it liable to injury during rotation. The lateral meniscus does not become distorted during rotation; it follows the lateral condyle of the femur by reason of the attachments of the ligaments of Humphry and Wrisberg and the popliteus muscle. It is thus relatively immune from injury daring rotation.

1. The pathology of avascular necrosis of bone and its relationship to the radiographic changes are considered briefly.

2. The inadequacy of radiographic examination in the early diagnosis of avascular necrosis is stressed.

3. Methods of early assessment of the residual vascularity of a bone mass are discussed.

4. Details of the principles, methods, and results of using radioactive phosphorus in the diagnosis of avascularity of bone are described.

5. The dangers and technical difficulties of using radioactive substances are discussed.

6. The possibility is envisaged that surgeons may soon be able to determine at the time of emergency operation whether the femoral head is dead or alive.