_Cirsoid aneurysm_ is usually met with in the course of the temporal artery, and may involve the greater part of the scalp. Large, distended, tortuous, bluish vessels pulsating synchronously with the heart are seen and felt. They can be emptied by pressure, but fill up again at once on removal of the pressure. The patient complains of dizziness, headache, and a persistent rushing sound in the head. Ulceration of the skin over the dilated vessels, leading to fatal hæmorrhage, may take place. They may be treated by excision, after division and ligation of the larger vessels entering the swelling; or the dilated vessels may be cut across at several points and both ends ligated. Krogius recommends the introduction of a series of subcutaneous ligatures so as to surround the whole periphery of the pulsating tumour, and interrupt the blood flow. Ligation of the main afferent vessels, or of the external or common carotid, has been followed by recurrence, owing to the free anastomatic circulation in the scalp. In some cases electrolysis has yielded good results. _Traumatic aneurysm_ of the temporal artery was comparatively common in the days when the practice of bleeding from this vessel was in vogue, but it is seldom met with now. _Arterio-venous aneurysm_ may also occur in the course of the temporal artery, as a result of injury, and is best treated by complete extirpation of the segments of the vessels implicated. CHAPTER XII THE CRANIUM AND ITS CONTENTS Anatomy and physiology--Cerebral localisation--Lumbar puncture. HEAD INJURIES--Concussion--Cerebral irritation--Compression--Contusion and laceration of the brain, and traumatic intra-cranial hæmorrhage: _Middle meningeal hæmorrhage_; _Hæmorrhage from internal carotid and venous sinuses_--Intra-cranial hæmorrhage of the newly born. Cerebral œdema--Wounds of brain--After-effects of head injuries--Traumatic epilepsy and insanity--Infective complications. #Anatomy and Physiology.#--The _Cranium_ is irregularly ovoid in shape, and its floor is broken up by various projections to form three separate fossæ--anterior, middle, and posterior--in which rest respectively the frontal, the temporal, and the occipital lobes of the brain; the cerebellum, pons, and medulla oblongata also occupy the posterior fossa.