1. Eayrs, J. T., Hormones in development (edit. by Hamburgh, M., and Barrington, E. J. W.) (Appleton-Century Crofts, New York, 1971).
2. Berry, M., and Rogers, A. W., J. Anat., 99, 691 (1965).
3. Dobbing, J., and Sands, J., Nature, 226, 639 (1970).
4. Munro, H. N., and Fleck, A., Methods of biochemical analysis, XIV, 113 (1966).
5. Thorson, S. C., Mincey, E. K., McIntosh, H. W., and Morrison, R. T., Br. med. J., 2, 67 (1972).