1. For the structure of the genetic code and the evidence for nonsense triplets see the papers in the Cold Spring Harbor Symposium XXXI on “The Genetic Code”, 1966 (in the press).
2. Weigert, M. G., Lanka, E., and Garen, A., J. Mol. Biol., 23, 391 (1967).
3. Sarabhai, A., and Brenner, S. in preparation.
4. Barnett, L., Brenner, S., Crick, F. H. C., Shulman, R. G., and Watts-Tobin, R. J., Phil. Trans. Roy. Soc. (in the press).
5. Brenner, S., Stretton, A. O. W., and Kaplan, S., Nature, 206, 994 (1965).