1. Young, D., in Developmental Neurobiology of Arthropods (edit. by Young, D.), 179–202 (Cambridge University Press, London, 1973).
2. Carbonell, C. S., Smithson. misc. Collns, 107, 1–23 (1947).
3. Pearson, K. G., and Iles, J. F., J. exp. Biol., 54, 215–232 (1971).
4. Cohen, M. J., and Jacklet, J. W., Phil. Trans. R. Soc., B 252, 561–592 (1967).
5. Pearson, K. G., and Bradley, A. B., Brain Res., 47, 492–496 (1972).