Abstract
In earlier papers the present author (Forsberg, 1963, 1965a, b; Forsberg & Olivecrona, 1964) has presented studies of the derivation and differentiation of the vaginal epithelium by morphological, histochemical and autoradiographic methods and by counts of mitotic rates. These investigations favour the view that the vaginal epithelium in mouse and rat has a dual origin: the anterior part being derived from the Müllerian epithelium and the posterior part from the sinus epithelium. This means that in these species the pseudostratified columnar Müllerian epithelium in the vaginal region undergoes a transformation into a stratified squamous epithelium. The possible mechanism behind this transformation has been discussed (Forsberg & Olivecrona, 1965). Results from estradiol treatment of neonatal mice during the differentiation of the vaginal epithelium support the above-mentioned investigations. (For a detailed review on the problem of the derivation of the vaginal epithelium, see Forsberg, 1963.)