1. Ogston, Nature, 162, 963 (1948).
2. Potter and Heidelberger (in the press).
3. Thesis submitted by Philip E. Wilcox to the Graduate School of the University of Wisconsin in partial fulfilment of the requirements for the degree of doctor of philosophy.
4. Marckwald, Ber., 37, 349 (1904).
5. Ritchie, “Asymmetric Synthesis and Asymmetric Induction", 17 (Oxford Univ. Press, London, 1933).