The term "congenital dacryocystitis" is a misnomer. The condition develops after birth, and not before, and is not a true inflammation of the sac wall, but an infection of the retained excretions from the conjunctival sac. The condition that predisposes to this postnatal infection, however, is congenital in the sense that there has been a delay in Nature's process of canalization of the lacrimal passageways. This is manifest in at least 95 per cent. of all cases by delayed opening into the inferior nasal wall.
We are indebted to Born, Legal, Kolliker, Ewetzky, Schaeffer and others for our knowledge concerning the embryologic development of the nasolacrimal passageways; but to Schaeffer, perhaps, belongs the credit of a more thorough study of the subject in the human embryo, commencing when the initial cells are laid down and continuing the study until it is complete at the end of gestation. From his investigations,