The sympathetic _caroticus cephalicus_ nerve, a third trunk extending to the head, after emerging from the large superior cervical nerve ganglion, receives some small branches from the glosso-pharyngeal ganglion, and then enters, in a horizontal manner, a foramen, the canalis caroticus externus, located in the lower part of the basi-occipital and the sphenoid bone. The anterior opening of this foramen, or canal, is close to the posterior part of the pterygoid bone. Inside this canal the sympathetic caroticus cephalicus receives a small branch which extends in a straight line from the basal part of the facial nerve. After receiving this branch, the nerve trunk, passing to the ear drum, lies close to the petrosum and the sphenoid. It is covered by the masseter muscle. The carotic ganglion is located at the point of the fusion of the caroticus cephalicus with the main trunk. At this point the caroticus cephalicus divides into two branches. The first is the superior recurrent nerve, which lies close to the upper surface of the alæ of the sphenoid, passes between the obliquus externus and the orbital wall, around the eyeball, and finally into the orbital septum and the internal muscles of the eye. It communicates with the ophthalmic nerve and sends twigs to the lacrimal gland, the gland of Harder, the upper eyelid, and the nose. The orbito-nasale ganglion is located where these nerves communicate near the nasal region. The second branch of the sympathetic caroticus cephalicus is the inferior recurrent nerve. This branch passes forward and dorsally from the pterygoid bone to a point where the upper rim of the rising wings of the jaw bone meets the sphenoid rostrum. In this course, some branches are given off to the pharynx, one branch near the lacrimal gland, and a branch which communicates with the superior maxillary nerve just before the nerve enters the jaw bone. The spheno-palatine ganglion is at the point of fusion. The terminal branches of the spheno-palatine are distributed to the hard palate, the nose, and the lacrimal gland. From the large cervical nerve ganglion and near the roots of the caroticus cephalicus are given off a few small nerve fibers which pass alone to the pharynx or accompany the jugular nerve branches, and fuse with the main trunk of the caroticus cephalicus nerve.