eye, and by their action contribute to our perception of the
relative position of objects. There is a leash of four muscles rising
from a spot behind the exit of the optic nerve from the cranium to the
upper, under, anterior, and posterior sides of the eyeball. These are
the superior, inferior, anterior, and posterior recti. Running from the
front of the orbit obliquely to the underside of the eyeball is the
inferior oblique muscle. Corresponding to it above is a superior oblique.
A lachrymal gland lies in the postero-inferior angle of the orbit, and a
Handerian gland in the corresponding position in front. In addition to
the upper and lower eyelids of the human subject, the rabbit has a
third, the nictitating lid, in the anterior corner of the eye.