1. The frequency of variable degrees of ischaemia of soft tissue in closed tibial and fibular shaft fractures is emphasised.

2. Two cases with ischaemia of calf musculature are described.

3. A follow-up study of 100 cases of closed tibial shaft fractures is analysed; ten patients were found to be affected.

4. The anatomical and pathological changes are discussed.

5. A plea is made for early surgical exploration in cases manifesting signs of ischaemia.

1. Cancellous bone cubes from calf and man were deproteinised with hydrogen peroxide and with ethylenediamine.

2. Long bones were removed aseptically from sheep, stored in the bone bank and used for cancellous homografts.

3. Holes were drilled in the upper part of the tibia or ulna or in the lower part of the femur of sheep. Some were left empty; others were filled with plugs of the deproteinised heterogenous bone, with autografts, or with homografts.

4. Histological appearances were studied after seventeen and thirty-six days.

5. At seventeen days repair was more advanced in the plugged holes; the biological result was better with the ethylenediamine-treated than with the peroxide-treated material. After thirty-six days repair was at an advanced stage. As much new bone had been deposited on the trabeculae of the deproteinised heterografts as on those of the homografts.

6. There was no evidence of metaplastic bone formation; new bone seemed to form from endosteal osteoblasts.

7. Certain clinical implications are briefly discussed.

1. Five cases of bilateral glenoid hypoplasia are described. Flattening of the humeral heads and sometimes other skeletal abnormalities coexisted.

2. The condition is considered to be congenital.

3. The differential diagnosis and etiology are discussed.