2. _Aneurysmal symptoms._ The tumour pulsates synchronously with the heart’s beat, whilst compression of the common carotid of the same side results in cessation of pulsation and great diminution in the size of the aneurysmal swelling. On releasing the compression force the tumour regains its original size in two or three beats of the heart, and, for a short time, pulsates more forcibly than before. A definite thrill is imparted to the examining finger, and, on auscultation, a loud murmur is heard, not only over the tumour itself, but also widely conducted over the bones of the vault, especially along the line of the superior longitudinal sinus. The free collateral circulation between the angular and ophthalmic arteries permits of the involvement of vessels in the inner orbital and upper nasal regions. This is well shown in the case depicted in Fig. 61. [Illustration: FIG. 61. A CASE OF TRAUMATIC ORBITAL ANEURYSM.] 3. _Pressure symptoms._ The impairment of venous flow in those radicles which drain into the cavernous sinus is evidenced by the marked engorgement of palpebral, conjunctival, episcleral, and retinal veins. Obstruction to lymph flow is shown by a hazy cornea, chemosis, and œdema of the parts surrounding the orbit. The danger thus incurred by the cornea is rendered more serious by the inability on the part of the patient to close the eyelids over the protruded globe. Keratitis and sloughing of the globe are to be feared. From muscular involvement, squints and diplopia are frequently observed. The pupil may be fully dilated through paralysis of the third nerve. 4. _Subjective symptoms._ Defect in vision is experienced at an early date, but perhaps the most prominent subjective symptom lies in ‘noises in the head’, compared by the patient to the thud of a steam-hammer, the whirring of wheels, the buzzing of bees, &c. These noises are more or less constant, most annoying to the patient, and increased on bending down, straining, &c. All these symptoms tend to become more severe as time lapses, though cases have been recorded in which the symptoms remained _in statu quo_. In the event of failure at relief or cure, the patient runs considerable risk of losing his sight from corneal ulceration, whilst repeated hæmorrhages and secondary infection may place the patient in imminent danger of his life. =Treatment.= In the consideration of the treatment of this condition, the results obtained in the 26 cases investigated will afford a valuable guide. In 4 cases an expectant attitude was adopted, the patient being kept quiet, restricted in diet, and dosed with potassium iodide. One case improved, two experienced no material benefit, and the fourth, dissatisfied, discharged himself from the hospital.