FIG. 38. TO ILLUSTRATE THE PROBABLE SOURCE OF PROFUSE HÆMORRHAGE FROM THE EAR. A, The fracture the roof of the external auditory meatus. B, Comminution of the tegmen tympani, the fracture involving the groove for the posterior branch of the middle meningeal artery.] (_b_) _Hæmorrhage from the ear and mouth._ The great majority of middle fossa fractures involve the external auditory meatus, passing inwards across the roof and floor of the middle ear towards the body of the sphenoid. Examination will show that the fracture passes inwards towards the junction of the inner and anterior walls of the middle ear, that is to say, towards the tympanic orifice of the Eustachian tube. The membrana tympani undergoes a variable degree of destruction. In the lesser cases the membrane is torn in its upper and front part only--in the region of the membrane of Shrapnell--whilst in the more serious cases it may be completely destroyed. The blood that escapes from the ear is derived from those vessels that supply the lining cuticle of the external and middle ears, from the numerous tympanic vessels, from the lateral sinus, and from the middle meningeal artery. The amount of blood which escapes varies according to the source of the hæmorrhage. When hæmorrhage occurs from the smaller vessels, the blood either clots in the external meatus or trickles from the ear. In the most severe cases the hæmorrhage is profuse and long-continued. Some years ago a case came under my observation that threw light on the probable source of such severe hæmorrhages. A man was admitted into the hospital, suffering from profuse hæmorrhage from the ear as the result of a fall down an area. The bleeding continued for fourteen hours, soaking the dressings and continuing so long as the man lived. At the post-mortem examination an extensive comminution of the tegmen tympani was discovered, the fracture being associated with great extra-dural extravasation of blood from a lacerated middle meningeal artery. The extra-dural hæmorrhage was enabled to escape through the tegmen tympani into the middle ear, and thence by means of the lacerated membrana tympani (see Fig. 38). Profuse and long-continued hæmorrhage from the ear should always arouse suspicion as to the possibility of injury to the middle meningeal artery. Since meeting the case recounted above, many similar cases have come under my care, and, in several instances, guided by this symptom alone, operative measures have been carried out successfully. The two following cases show, however, that the extra-dural extravasation may be derived not only from the middle meningeal artery but also from the lateral sinus.