Examination of tissue sections from biopsy specimens obtained from affected foci on the scalp revealed different findings at different stages of the process (Figures 7, 8, 9 and 10). Unfortunately, we have no instructive examples of very early lesions, that is, lesions that appear before alopecia is obvious clinically. The earliest findings observed by us are a superficial perivascular and lichenoid peri-infundibular infiltrate of lymphocytes followed in time by peri-infundibular fibroplasia. As the process progresses, the lichenoid infiltrate wanes and the fibrosis waxes, the fibroplasia giving the appearance of "strangling" the epithelium of the upper segment of the follicle. The number of follicles in anagen is decreased, and the number in catagen and telogen is increased. Later still, the number of follicles in anagen decreases further and, at sites where follicles resided formerly, fibrous tracks are widened by thickened bundles of collagen. Degenerated glassy membranes (basement membranes that envelop the lower segment of follicles normally), often several of them, are situated within the altered fibrous tracks and represent the residuum of the inferior segment of follicles which have participated in more cycles of progressively lessened length. Follicles still in anagen are shortened and thinned. At the end of the process, hardly a follicle is terminal and in anagen; the few follicles in anagen are vellus. Most of the follicles are in telogen. Altered fibrous tracks dominate. Subtle fibrosis may be present in the upper part of the dermis. Episodically, hair shafts are noted within the reticular dermis, having been wrenched by traction from the viable component of follicles, and there are surrounded by histiocytes, some of them multinucleate, in the manner of a foreign-body reaction.