Lacrimal Apparatus.

Lacrimal Apparatus.

This consists, first, of a gland for the secretion of the tears, and, second, of a series of canals for the conveyance of the superfluous tears into the cavity of the nose.

The gland is situated above the outer part of the eyeball, and the tears which have flowed over the eye and reached the inner angle are there directed by a small, conical papilla (lacrimal caruncle) into two minute orifices, and thence by two ducts (lacrimal) to a small pouch (lacrimal sac) from which a canal leads through the bones of the face into the nose. This opens in the lower part of the nose on the floor of the passage and a little outside the line of union of the skin which lines the false nostril with the mucous membrane of the nose. In the ass and mule this opening is situated on the roof instead of the floor of the nose, but still close to the external opening.

Plate XXII.
Diagrammatic vertical section through horse's eye.