“_The simplest method for removing the ear_ for the sake of dissection is, after the removal of the calvarium in the usual way, to take out both the petrous bones together by means of two transverse vertical sections, one in front of the two petrous bones and the other posterior to them. The anterior of these sections should pass in a line a little anterior to the anterior clinoid processes, and the posterior in a line through the posterior third of each mastoid process. By means of these two sections, the trumpet-shaped extremity of each Eustachian tube, a portion of the mucous membrane of the fauces, and the whole of each petrous bone, together with the mastoid processes, can be taken out. “The disadvantage of this procedure is the disfigurement which is apt to ensue from the falling in of the face. To avoid this disadvantage, another mode of removing the ear may be resorted to. This consists in taking out each petrous bone separately in the following manner: The calvarium having been sawn off, an anterior section is to be made in each side in the same line as in the above plan, but extending only as far as the outer part of the body of the sphenoid bone; a posterior section in each side is then to be made, as in the first plan, but not extending farther inwards than the basilar process of the occipital bone. These two sections are to be made with a saw or with a chisel and hammer. The apex of each petrous bone is then to be separated from the sphenoid and occipital bones, and each petrous bone (the outer ear and integument being detached and reflected downwards) is to be drawn outwards, taking care, by inserting the scalpel deeply, to remove as much of the soft parts as possible. “The organ of hearing having been removed, the dissection may be conducted in the following manner: The auditory nerve in its meatus should be first carefully examined, presuming that a previous inspection has been made of the portion of the brain to which the portio mollis and portio dura nerves are attached. The size of the external meatus having been ascertained by allowing a strong light to fall into it, its anterior wall is to be removed by the cutting forceps.