754 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS (37) (3s) (39) (40) (41) (42) (43) (44) (45) (46) (47) (48) (49) (so) (51) (52) (53) (54) (55) (56) (57) (ss) (59) (6O) (61) (62) (63) (64) (65) (66) Oliver, R. F. in Fleischmajer, R. and Billingham, R. E. trpithelial-mesenchymal inter- actions 267 (1968) (Williams and W'ilkins, Baltimore). Oliver, R. F. The experimental induction of whisker growth in the hooded rat by im- plantation of dermal papillae. J. Ernbryol. Exptl. Morphol. 18 43 (1967). Cohen, J. Transplantation of hair papillae. Syrup. Zool. Soc. London 19, 83 (1964). Cohen, J. in Lyne, A. G. and Short, B. F. Biology of skin and hair growth 183 (1965) (Angus and Robertson, Sydney). Oliver, R. F. The induction of hair follicle formation in the adult hooded rat by vibrissa dermal papillae. J. Ernbryol. Exptl. Morphol. 9,8 219 (1970). Oliver, R. F. Unpublished results. Wessells, N. K. Differentiation of epidermis and epidermal derivatives. New Engl. J. Med. 2?? 21 (1967). Cohen, J. in Montagna, W. and Dobson, R. L. Hair growth 1 (1969) (Pergamon Press, New York). Wessells, N. K. Morphology and proliferation during early feather development. Develop. Biol. 12 131 (1965). Straile, W. E. in Montagna, W. and Dobson, R. L. Hair growth 369 (1969) (Pergamon Press, New York). Hardy, M. H. in Montagna, x•V. and Dobson, R. L. Hair growth 35 (1969) (Pergamon Press, New York). Montagna, W. and Chase, H. B. Histology and cytochemistry of human skin. X. X- irradiation of the scalp. Am. J. Anat. 99 415 (1956). Kligman, A.M. Pathologic dynamics of human hair loss. I. Telogen effluvium. Arch. Dermatol. 83 175 (1961). Ebling, F. J. and Johnson, E. Systemic influence on activity of hair follicles in skin homografts. J. Embryol. Exptl. Morphol. 9 285 (1961). Ebling, F. J. and Johnson, E. The control of hair growth. Syrup. Zool. Soc. London 12 97 (1964). Ebling, F. J. in Lyne, A. G. and Short, B. F. Biology of skin and hair growth 507 (1965) (Angus and Robertson, Sydney). Silver, A. F., Chase, tt. B. and Arsenault, C. T. Spontaneous and experimental hair growth of the mouse pinna. J. Invest. Dermatol. 48 444 (1967). Bullough, W. S. Mitotic and functional homeostasis: a speculative review. Cancer Res. 25 1683 (1965). Montagna, W., Chase, H. B., Malone, J. D. and Melaragno, H. P. Cyclic changes in poly- saccharides of the papilla of the hair follicle. Quart. J. Microscop. Sci. 93 241 (1952). Johnson, P. L., Butcher, E. O. and Beverlander, G. The distribution of alkaline phos- phatases in the cyclic growth of the rat hair follicle. Anat. Record 98 355 (1945). Hamilton, H. L. in Lyne, A. G. and Short, B. F. Biology of the skin and hair growth 313 (1965) (Angus Robertson, Sydney). Rudall, K. M. The size and shape of the papilla in xvool follicles. Proc. Int. Wool Textile Conf. Australia P F9 (1965). Van Scott, E. J. and Ekel, T. M. Geometric relationships between the matrix of the hair bulb and its dermal papilla in normal and alopecic scalp J. Invest. Dermatol. 81 281 (mSS). Van Scott, E. J., Ekel, T. M. and Auerbach, R. Determinants of rate and kinetics of cell division in scalp hair. J. Invest. Dermatol. 41 269 (1963). Priestley, G. C. and Rudall, K. M. in Lyne, A. G. and Short, B. F. Biology of the skin and hair growth 165 (1965) (Angus and Robertson, Sydney). Priestley, G. C. Histological studies of the skin follicle types of the rat with special reference to the structure of the Huxley layer. J. A nat. 101 491 (1967). Straile, W. E. in Lyne, A. G. and Short, B. F. Biology of the skin and hair growth 35 (1965) (Angus and Robertson, Sydney). Puccinelli, V., Caputo, R. and Ceccarelli, B. Changes in the basement membrane of the papilla and wall of the human hair follicle. •/rch. Klin. Exptl. Dermatol. 233 172 (1968). Parakkal, P. F. The fine structure of the dermal papilla of the guinea-pig hair follicle. J. Ultrastrucl. Res. 14 133 (1966). Oliver, R. F. The vibrissa dermal papilla and its influence on epidermal tissues. Brit. J. Dermatol. 81 Suppl. 3 55 (1969).

DERMAL PAPILLA AND THE DEVELOPMENT AND GROWTH OF HAIR 755 DISCUSSION PROF. F. J. G. EBLING: One aspect of your work which particularly intrigued me was your suggestion that oral epithelium, under the influence of dermal papilla, cannot quite decide whether to form a tooth-like or a hair-like structure. Could you expand this? THE LECTURER: Oral epithelium seemed to respond in two quite different ways under the influence of dermal papillae. Sometimes, and perhaps here understandably, it developed into recognisable hair follicle elements. However, at other times it closely resembled, particularly in its stellate reticulum-like configuration, enamel organ of early developing teeth. MRS. H. BUTLER: Did this phenomenon occur in lip as well as in gum epithelium? THE LECTURER: Yes. More hair follicles developed in lip epithelium than gum and stellate reticulum-like configurations in epithelia from both sites. DR. I. M. GInSON: Have you tried to develop hair follicles in the normally hairless epidermis of the rat foot pad? THE LECTURER: No, but Kollar (16) has induced follicle development in embryonic mouse foot pad epidermis. MR. K. M. GODFREY: Did you go far enough to allow the hair to grow and penetrate the epidermis? THE LECTURER: Yes. Hair follicles induced from ear epidermis grew hair above the ear surface.