_Politzer’s method_ of removing the auditory apparatus in connection with the nasopharynx and the Eustachian tubes is also shown in Fig. 32 by the lines _a_, _b_, _c_, _d_, _e_. Two drill-holes are made in the floor of the anterior fossa at _a_, 1 cm. to the right and to the left of the crista galli, extending vertically through the nasal cavity to the under surface of the hard palate. A fine key-hole saw is then introduced through the right drill-hole, and the base of the skull is then sawed in the lines _ab_, _bc_, _cd_ and _de_ as indicated in Fig. 32. Symmetrical cuts are then made on the left side following the same lines and the two drill-holes connected by a transverse saw-cut. Any remaining bony connections are then cut with a wide chisel. In order to cut the bony bridges in the region of the nasopharynx it may be necessary anteriorly to use the Hey-saw through the mouth-cavity as well as from the cranial side. To facilitate the removal of the loosened portion two parallel saw-cuts are made in the occipital bone 3 cm. to the left and right of the median line, extending nearly to the posterior edge of the foramen magnum and connected below by a slightly rounded cut as shown in Fig. 32. A long-armed chisel can now be used conveniently through the opening thus made, for horizontal manipulations upon the base of the skull, while the loosened portion of the base is lifted with the bone-forceps or nippers set in the posterior saw-cut _e_ and the _sella turcica_. As the bone is raised the posterior and lateral pharyngeal walls are cut with the cartilage-knife, the posterior wall of the capsule of the maxillary articulation on both sides severed, the jaw disarticulated, and all muscular and membranous connections cut, until the preparation is completely freed. The auditory apparatus and the Eustachian tubes can now be examined by any one of the methods given above.