The _external carotid_ and the cervical portion of the _internal carotid_ are seldom the primary seat of aneurysm, although they are liable to be implicated by the upward spread of an aneurysm at the bifurcation of the common trunk. In addition to the ordinary signs of aneurysm, the clinical manifestations are chiefly referable to pressure on the pharynx and larynx, and on the hypoglossal nerve. Aneurysm of the internal carotid is of special importance on account of the way in which it bulges into the pharynx in the region of the tonsil, in some cases closely simulating a tonsillar abscess. Cases are on record in which such an aneurysm has been mistaken for an abscess and incised, with disastrous results. _Aneurysmal varix_ may occur in the neck as a result of stabs or bullet wounds. The communication is usually between the common carotid artery and the internal jugular vein. The resulting interference with the cerebral circulation causes headache, giddiness, and other brain symptoms, and a persistent loud murmur is usually a source of annoyance to the patient and may be sufficient indication for operative treatment. #Intracranial aneurysm# involves the internal carotid and its branches, or the basilar artery, and appears to be more frequently associated with syphilis and with valvular disease of the heart than are external aneurysms. It gives rise to symptoms similar to those of other intracranial tumours, and there is sometimes a loud murmur. It usually proves fatal by rupture, and intracranial hæmorrhage. The treatment is to ligate the common carotid or the vertebral artery in the neck, according to the seat of the aneurysm. #Orbital Aneurysm.#--The term pulsating exophthalmos is employed to embrace a number of pathological conditions, including aneurysm, in which the chief symptoms are pulsation in the orbit and protrusion of the eyeball. There may be, in addition, congestion and œdema of the eyelids, and a distinct thrill and murmur, which can be controlled by compression of the common carotid in the neck. Varying degrees of ocular paralysis and of interference with vision may also be present. These symptoms are due, in the majority of cases, to an aneurysmal varix of the internal carotid artery and cavernous sinus, which is often traumatic in origin, being produced either by fracture of the base of the skull or by a punctured wound of the orbit. In other cases they are due to aneurysm of the ophthalmic artery, to thrombosis of the cavernous sinus, and, in rare instances, to cirsoid aneurysm. If compression of the common carotid is found to arrest the pulsation, ligation of this vessel is indicated. #Subclavian Aneurysm.#--Subclavian aneurysm is usually met with in men who follow occupations involving constant use of the shoulder--for example, dock-porters and coal-heavers. It is more common on the right side.