1. Naitoh, Y., and Kaneko, H., Science, 176, 524–532 (1972).
2. Holwill, M. E., and McGregor, J. L., Nature, 255, 157–158 (1975).
3. Hyams, J. S., and Borisy, G. G., J. Cell Biol., 67, 186 (1975).
4. Eckert, R., Science, 176, 478–481 (1972).
5. Eckert, R., Naitoh, Y., and Machemer, H., Symp. Soc. exp. Biol., 30 (edit. by Duncan, C.), (Academic, London, 1976).