1. Balazs, A., and Holmgren, H., Exp. Cell Res., 1, 206 (1950).
2. Fell, H. B., and Danielli, J. F., Brit. J. Exp. Path., 24, 196 (1943).
3. Firket, H., Arch. Biol., 62, 335 (1951).
4. Needham, A. E., “Regeneration and Wound-Healing”, 41 (Methuen and Co., Ltd., London, 1952).
5. Grogg, E., and Pearse, A. G. E., J. Path. Bact., 64, 627 (1952).