"<em>A</em>, membrane of hair follicle, showing cells with nuclei and pigmentary granules; <em>B</em>, external lining of root sheath; <em>C</em>, internal lining of root sheath; <em>D</em>, cortical or fibrous portion of hairshaft; <em>E</em>, medullary portion (pith) of shaft; <em>F</em>, hair bulb, showing its development from cells." — Blaisedell, 1904

Hair Follicle

"A, membrane of hair follicle, showing cells with nuclei and pigmentary granules; B,…