Before one can begin to consider the question of the authenticity of the concept of follicular "degeneration" as it relates to a "syndrome," it is essential to attain thorough familiarity with the rudiments of histologic aspects of a follicle. A follicle may be divided histologically into an upper segment and a lower segment. The upper segment is permanent and consists of an infundibulum and an isthmus. The boundaries of the infundibulum are the ostium of the follicle above and the point of entry of the sebaceous duct below. The boundaries of the isthmus are the point of entry of the sebaceous duct above and the site where corneocytes of the inner sheath desquamate below. The lower segment is transient and consists of a stem and a bulb. The stem stretches from the base of the isthmus to the summit of the bulb (marked by Adamson's fringe, i.e., the end of the keratogenous zone where nucleated corneocytes of an emerging hair become anucleate), and the bulb extends from Adamson's fringe to the base of the follicle. Viewed in cross section, the stem, throughout its length, consists of an outer sheath, an inner sheath, and a hair. The inner sheath comes into being as a consequence of maturation of matrical cells in the bulb and is recognizable there by the presence of bright red trichohyalin granules, and in the stem it is identifiable by the presence of blue-gray corneocytes arranged compactly. Never do the corneocytes that make up the inner sheath "degenerate" or "disintegrate;" they eventually desquamate at a site that becomes the lower boundary of the isthmus.