1. Machin, K., and Pringle, J. W. S., Proc. Roy. Soc., B, 151, 204 (1959).
2. Jewell, B., Pringle, J. W. S., and Rüegg, J. C., J. Physiol., 173, 6 (1964).
3. Hodge, A. J., J. Biophys. Biochem. Cytol., 2, Supp., 131 (1956).
4. Huxley, H. E., and Hanson, J., Electron Microscopy Proc. Stockholm Conf., Sept. 1956, Uppsala, 202 (1957).
5. Auber, J., and Couteaux, R., J. Microscopie, 2, 309 (1963).