Melanocytes are present in the respiratory mucosa, mucous glands and superficial and deep stroma of the nasal cavity. These cells are present in the stroma of most Caucasian and all Negro adults. Intraepithelial melanocytes occur focally and are observed only in adult Negroes. No melanocytes are found in young Negro children. The presence of melanocytes within mucous glands termed melanogenic metaplasia is not limited to the oral cavity and larynx but was also noted in this study in the nasal cavity. The occurrence of melanocytes in the nasal cavity explains the histogenesis of melanomas as primary neoplasms without an antecedent squamous metaplasia or the previous formation of nevus cells.