Our knowledge concerning the structure, distribution and function of the normal glomus has been greatly expanded since the original description by Masson1 in 1924 of a tumor which resembled the glomus coccygeum of Luschka. Masson's description of the glomus tumor and Popoff's2 subsequent studies concerning the distribution and alterations of the normal cutaneous glomus in conditions involving the peripheral vascular bed have stimulated interest in this subject.
It was suggested that the glomus tumor should not be regarded as a neoplasm but as an exaggerated development of a normal structure. This conception would simplify our understanding of the tumor and aid us in explaining its physiologic manifestations. Regarding its development and distribution, it is of practical importance as well as of academic interest that the normal glomus, which represents a cutaneous arteriovenous anastomosis, is not present before birth and does not begin to develop in the infant until