1. Johnson, B., Austral. J. Sci., 18, 199 (1956).
2. Wigglesworth, V. B., and Gillett, J. D., J. Exp. Biol., 11, 120 (1934).
3. Kennedy, J. S., and Booth, C. O., Discovery, 17, 311 (1956); J. Exp. Biol., 40 (in the press).
4. Jones, M. G., Proc. Roy. Entomol. Soc. Land., A, 19, 13 (1944).
5. Slifer, E. H., and Sekhon, S. S., J. Morph., 109, 351 (1961).