wlle the damaze is spotty in character with areag of damage surrounded by rela~ tively ncrmal tissue. The histcpathological changes induced in the skin by faliout in the Marshallese lesions were studied in section of a number of biopsies taken during the first 7 weeks, at 6 months and at 2 years. changes can be found elsewhere (Conard et al.). seen are summarized below. Details of these Some of the major chanjes During the early,acute period of the lesions, the epidermis showed marked damage characterized by atrophy and flattening cf the rete pegs with disorganization of malpigian and basal layers and marked cellular changes (pleomorphic nuclei, pyknosis and cytoplasmic halos). Additional features were atrophy or absence of the stratum granulosun, im perfect keratinization, and loose fibrillation and hyperkeratosis of the stratum corneum. Celis laden with pigment were frequently present through~ out the epidermis. In the dermis the changes were largely confined to the upper part with edema, telangiectasis of vessels with perivascular infile tration of lymphocytes. Chromatophores filled with melanin were prominent. Fig. 10 shows scme of these changes in a pigmented legion biopsied 3 weeka after exposure. By six months there was ccnsiderable improvement in the histological appearance of the lesions. in virying degrees: The following changes were found to persist focal atrophy of the stratum granulosum, slight focai pigmentary disturbances in cells of the basal layer, and slight disturbances in polarity of the epithelial cells in basal papiliary projections. In the dermis, telangiectasis of slight to moderate degree persisted. At two years, biopsies at sites of persistent gross abnormalities re=- vealed that none of the lesions were neoplastic or showed alterations suggestive of a precancerous condition, In scme sections, acanthosis, absence