1. John, A., in Organogencsis (edit. by de Haan R. L., and Ursprung, H.), 611 (Holt, Rinehart and Winston, New York, 1965).
2. Singh, R. P., and Carr, D. H., Anat. Rec., 155, 369 (1966).
3. Beatty, R. A., in Intersexuality (edit. by Armstrong, C. N., and Marshall, A. J.) 17 (Academic Press, London and New York 1964).
4. Witchi, E., Contrib. Embryol. Carnegie. Inst., 32, 67 (1948).
5. Torrey, T. W., Amer. J. Anat., 76, 375 (1945).