372 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS - . • ß . • ---- - . , •..•.•- . •.• ...... •.. . • ß -- . --,• • •. - • ..- -. • •.,* , • '• ., • ,•..•-. • ' •-. . • ....• . : • •' .... : • • . .. . • . , -- . -•-• Figure 8. Transmission electron micrographs of Caucasian beard (left) and scalp hair (right) cuticle cross-sections. Magnification 36,•x. same subject (Table IV, Figure 8). The thickness of individual cuticle cells was about 0.5/xm in both cases. While the gross surface structure appeared to be similar in facial and scalp hair, larger areas of the cuticle cells were exposed and the scale pattern was more ordered on scalp fibers (Figure 9). Cylindrical fibers and the convex portions of flattened or irregular fibers had wider, more oblong shaped cuticle cells. Distal edges of cuticle scales on beard hairs were often less chipped than on the corresponding scalp hairs. This was probably due to less mechanical damage having been inflicted by grooming practices on the beard than on the scalp hairs. On scalp hairs within a few millimeters of the skin line this scale edge damage was not apparent. Longitudinal sections of beard hair, examined in the TEM or under polarized light, usually revealed a continuous or discontinuous medulla, representing material joined by a filamentous network parallel to the long axis of the fiber (Figures 10, 12). By comparison, scalp hairs were much less extensively medullated. However, even scalp or facial hairs from the same individual showed significant variation in medullation. The studies also demonstrated, particularly in beard hairs, that the melanin pigment granules appeared not only in the cortical cells, as commonly reported in the literature, but also in the cuticle and medulla (Figures 13-14), especially in heavily pigmented Chinese hair (Figure 15) or Negro hair.

COMPARISON OF BEARD AND SCALP HAIR 373 / " . .-,- ......... . • .... . ": :.. ':. •'• •,' .... _ ........... .• % .-•.... • ... ...... , ..... •.. • :.: ........ ,•.: . .. ,.• ............ • • ..... :. ...... .......... ::•, • ' •-' . '- .• .• . c .... -• • • . • •'-' • . : • .•: • • • . :.'.• •. . ..• ' '.-•- • -- '• '" :-r • •':'• • " *•' •, •'• •- : . . -.:., • •.. • • • • .-• •."'. ... - ". .• .. - . • .. . • -. . • . Figure 9. Comparison of the cuticul• patterns of Caucasian scalp hairs (A, B) and beard hairs (C, D). Magnifications l•x (A, C) and 2•x (B, D).