1. Freeman, M. A. R., and Wyke, B. D., J. Anat. (Lond.), 98, 299 (1964).
2. Greenfield, B. E., and Wyke, B. D., J. Anat. (Lond), 98, 300 (1964).
3. Kirchner, J. A., and Wyke, B. D., J. Anat. (Lond.), 98, 684 (1964).
4. Kirchner, J. A., and Wyke, B. D., Nature, 203, 1243 (1964).
5. Freeman, M. A. R., and Wyke, B. D., J. Bone Joint Surg. (to be published).