Postnatal transformation of the epithelium lining the nasolacrimal duct of the mouse.

The nasolacrimal duct of the newborn mouse was lined with the stratified cuboidal epithelium, while in the mouse after 15 days of age the epithelium was stratified squamous. Further, in the adult mouse the epithelium could not be classified definitely as typical stratified squamous epithelium, but was somewhat modified. It is suggested that the stratified cuboidal epithelium corresponds to the "intermediate epithelium (NAKANO 1986)", and transforms into the modified stratified squamous epithelium with passing through the typical stratified squamous epithelium.