Abstract

PIP: Lack of uniformity of opinions concerning the development of the vag ina prompted an investigation into the successive stages of the vagina's developmental events. Observations on the material studied indicated: 1) that the upper part of the vagina develops from the mullerian ducts: 2) the lower part of the vagina is formed from the urogenital sinus in an area fromerly occupied by the mullerian tubercle; it is here that the hymen forms; 3) the hymen is formed passively by the invagination of the posterior wall of the sinus attributed to expansion of the vagina's lower end and; 4) formation of the vagina occurs without the participation of the wolffian ducts which involute at 50mm and usually rapidly and entirely disappear from the genital cord. These observations suggest that a caudocranial process occurs in which epithelial cells in the center of the solid cord undergo involution, desquamate and are discharged in part of the hymenal opening thus forming the vaginal canal.