Immunohistochemical staining for S-100 protein was carried out on one case of von Recklinghausen's neurofibroma and one of giant congenital nevus. Uniformly positive staining was ootained in all cells of the numerous pseudomeissnerian corpuscles in both cases. These structures thus appear, like the true Wagner-Meissner tactile nerve endings, to consist entirely of Schwann cells and not to contain any demonstrable perineurial component.