Nail

(mil). The horny lamina covering the dorsal aspect of the end of each finger and toe. N.-area, a thickening of the epitrichium over the end of the digit, marked out quite definitely by a limiting groove that persists more or le distinctly throughout life. It first appears in the human embryo about the beginning of the third month. N.-bed, the depre ion in which the nail rests. N.-bone, the lacrymal bone or os unguis. N. -brush, a hand brush for cleaning the finger-nails. N. -culture, a term applied in bacteriology to a stab-culture showing a growth along the needle-track, and en the surface a button-like projection, giving the appearance of a nail driven into the gelatin. N.-file, a small single-cut file for trimming the finger-nails. N.-fold, the portion of epi- Ungual Extremity of Finger, showing Nail.. Fold of skin covering root of nail. 2. Incised and turned back. 3. Semilunar portion of sub ungual skin. 4. Portion corresponding to body of nail. 1106 2 7 3 H Longitudinal Section Ungual Extremity Finger, showing Nail. Concave Aspect of 1. Its proximal border.: Portion corresponding t lunula. 3. Body. 4. Frc distal border.:. Corneous layer of epider mis of dorsal aspect. 2, Re flection of this la. 3. Superficial layer o: nail. 4. Corneous epiderm of pulp of finger 5. Rete Malpignii of dorsa aspect. 6. Refleetii layer. Second retl 8. Rete ol finger. 9. Derma ol aspect. 10. derma, n. Second tion of derma. 1. of palmar aspect of finger 13. Ungual phalanx. dermis that covers the root and edges of the nail. N. groove, the depre ion for the insertion of the nai N., Hang, a little shred of skin hanging from th finger at the side of the nail. Hang-nails are times quite painful, and the little wounds offer trance to septic matter. N., In fleshed, Ingrow ing, or Ingrown, an overlapping of the nail by th flesh, from pre ure, attended with ulceration. Nmatrix, the proximal end of the N.-bed; the ture from which the nail grows. N.-pad. The as N. -rampart. N. -plate, the volar side ol N. -rampart, the epidermic border against which th margin of the nail rests. N., Reedy, N., a nail presenting longitudinal furrows. N.-root, li portion of the nai: attached to the X. -matrix. N Spring. Same as Hang-nail. N., Turtle-back, ' name given by S. Weir Mitchell to a nail curved in all directions; it is a condition seen in certain trophic disturbances. N.-wall. The same as N. -rampart.