1. Staba, E. J., et al., in: Proc. Internatl. Conf. on Plant Tissue Culture. Ed. byP. R. White andA. R. Grove. S. 191. Pennsylvania 1965.
2. Carew, D. P., andE. J. Staba: Lloydia28, 1 (1965).
3. Bell, R. C., andL. H. Briggs: J. Chem. Soc.1942, 1.
4. Rao, P. S., andS. Narayanaswami: Planta (in press).