THE HUMAN SCAI,P AS A HABITAT FOR YEASTS 87 Preliminary studies undertaken by the authors indicate the possibility that both P. ovale and Rh. mucilaginosa are capable of utilizing keratin as a source of nitrogen following the technique of Kapica and Blank (15, 18). If such is the case the parasitic nature of these organisms would be es- tablished. SUMMA RY 1. The yeast flora of the scalps of 189 college seniors has been in- vestigated. 2. From 122 of these individuals (65%) a total of 145 yeasts were isolated by culture and were identified according to the monograph of Lodder and Kreger-Van Rij. 3. The 145 yeasts were represented by 14 species. 4. The three most prevalent yeasts were Pityrosporum ova/e, Candida parapsi/osis, and Rhodotorula mucilaginosa. 5. A comparative study was made with other surveys of yeasts of skin surfaces, which also showed that C. parapsilosis and Rh. mucilaginosa were common yeasts found on the scalp and on other skin surfaces. 6. Because of the frequency with which C. parapsilosis has been iso- lated fi'om onychomycotic infections and because of its proved keratin- olytic activity an association with pathological scalp conditions is sug- gested. Preliminary studies indicate a similar activity for P. ovale and Rh. mucilaginosa. 7. There is no evidence from this paper or from a survey of the litera- ture that any of the other yeasts isolated could be causative of a pathologi- cal condition of the scalp. 8. This survey shows that the human scalp harbors yeasts in greater abundance and variety than other areas of the body. 9. The prevalence of P. ovale as reported by other workeri has been substantiated by this survey. (Received September 12, 1962) REFERENCES (1) Rivolta, S., Paraesiti Vegetali Torino, 469 (1873). (2) Gots, J. S., Thygeson, P., and Waisman, M., vim. 5•. Ophthalmol., 30, 1485 (1947). (3) Gordon, M. A., 5 e. Invest. Derrnatol., 17, 267 (1951). (4) Benham, R. W., Ibid., 2, 187 (1939). (5) I.odder, J., and Kreger-Van Rij, N.J. W., "The Yeasts: A Taxonomic Study," Amster- dam, North Holland Publishing Co. (1952). (6) Wickerham, L. J., "Taxonomy of Yeasts," U.S. Dept. vigr. Tech. Bull. 1029 (May) (1951). (7) Huxley, M. J., and Hurd, R. C., pt. Bacleriol., 71, 492 (1956). (8) Connell, G. H., and Skinner, C. E., Ibid., 66, 627 (1953). (9) Croft, C., and Black, L. A., 7- Lab. Clin. Meal., 23, 1259 (1938). (10) DiMenna, M. E., pt. Pathol. Bacteriol., 38, 89 (1954). (11) Skinner, C. E., Connell, G. H., and Hurd, R. M., Bact. Proc. (Soc. vim. Bacteriologists), 52, 86 (1952). (12) Benham, R. W., and Hopkins, A.M., At. M. At. virch. DermatoL, 28, 532 (1933).

88 JOURNAL OF THE SOCIETY OF COSMETIC CHEMlSTS (13) Sturde, H. C., .4rch. klin. u. exptl. Dermatol., 203, 266 (1956). (14) Rieth, H., ]bid., 207, 413 (1958). (15) Kapica, L., and Blank, F., Dermatologica, 117, 433 (1958). (16) Fischer, E., Schweiz. Z. allgem. Pathol. u. Bakteriol., 18, 1 (1955). (17) Nino, F. L., Urzua, L. F., Nolte, A. L., 3lycopathol. et Mycol..4ppL, 5, 250 (1951). (18) Kapica, L., and Blank, F., Dermatologica, 115, 81 (1957). (19) Ota, M., and Huang, P. T., .4nn. parasitol. humaine et comparge, 11, 49 (1933). (20) MacKee, G. M., and Lewis, G. M., f. ]nvest. Dermatol., 1, 131 (1938). (21) Benham, R. W., ]. Infectious Diseases, 57, 255 (1935). (22) Spoor, H. J., Traub, E. F., and Bell, M., .4. M..4..4rch. Dermatol. and Syphilol., 69, 323 (1954).