1. Cowan, S. T., in Microbial Classification, edit. by Ainsworth, G. C., and Sneath, P. H. A., 433 (Cambridge University Press, 1962).
2. Anon, Liturgical Constitution, Second Vatican Council. Const, art., 36, 3 (1964).
3. Bawden, F. C., Plant Viruses and Virus Diseases, fourth ed. (Ronald, New York, 1964).
4. Lwoff, A., Horne, R., and Tournier, P., Cold Spring Harbor Symp. Quant. Biol., 27, 51 (1963).
5. Cowan, S. T., J. Gen. Microbiol., 39, 143 (1965).