DURING the period of World War II, approximately 8,000 specimens of skin were received at the Army Institute of Pathology for histologic consultation. It is well known that there are problems associated with the diagnosis of disease from a section of skin that do not obtain in nearly as great a degree to other tissues. In a considerable number of cases, changes in the skin produced by a large assortment of agents are histologically indistinguishable from each other. In such instances the clinical evaluation of the lesions must necessarily guide the pathologist's diagnosis. Ideally, each case should have been discussed by the consulting pathologist and the clinician. Inasmuch as this was manifestly impossible, the former had frequently to rely on the clinical history and the occasional clinical photographs submitted with the protocols. Often the histories either were not included or were inadequate. Notwithstanding these limitations, it is clear that there