The external carotid may be tied either above or below the crossing of the posterior belly of the digastric muscle. For the latter purpose an incision should be made through the integuments and platysma myoides, from beneath the angle of the jaw to the side of the thyroid cartilage. This incision will expose the digastric muscle, and by drawing it a little upwards the artery may be exposed and secured beneath the origin of its superior thyroid branch. Care should be taken not to include the superior laryngeal nerve, which descends obliquely inwards behind the origin of the external carotid. Mr. Guthrie is of opinion that the ligature should be applied near its origin, that is, immediately below where the superior thyroid artery is given off. In opening abscesses of the tonsil it should be borne in mind that the convexity of the external carotid may be closely applied to the outside of the swollen gland.

The branches of the external carotid artery are nine in number, and may be included under the following heads :

Anterior. Internal, or Ascending.

Superior Thyroid. Pharyngea Ascendens. Lingual.

Facial or Labial. External.

Transversalis Faciei.

Posterior. Terminating.

Occipital. Superficial Temporal.

Posterior Auricular. Internal Maxillary.