Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 8 On the Ossicles That Enter Upon the Construction of the Organ of Hearing

Appendix: 1555 version of the first 32 lines of the chapter 8 narrative (see note 6 above)

Although in the seventh book we shall deal at length with the structure of the instrument of hearing along with the other sensory organs, this structure must now be described in passing because of certain ossicles which it contains, lest by reserving them entirely until the seventh book we seem to have passed them over in an otherwise comprehensive account of the bones. It is conjectured that neither Galen nor any other before him had seen these ossicles — and several others besides — from the fact that no mention of them is ever made. A large and quite irregular cavity (in the principal illustration, and in the penultimate text figure of ch. 12) is carved in the temporal bone, with four foramina coming out from it. The first of these [meatus acusticus externus] (a in fig. 3, ch. 12) is wide but circuitous, on each side admitting the nerve 15 (a in figs. 1, 2, ch. 2 bk. 4) of the fifth pair of cerebral nerves into the region of the head where the cerebrum is contained. The second foramen [meatus acusticus internus] (a in fig. 3, ch. 12), shorter but much wider than the one just mentioned, runs to the ear. The third [f. stylomastoideum] (b in fig. 2, ch. 12) is narrow and variously twined; it is called the blind foramen, as we shall explain later, and transmits a branch (c in figs. 1, 2, ch. 2 bk. 4) of the nerve [n. facialis] of the fifth pair. The fourth [tuba auditoria, pars ossea] (V in fig. 2, ch. 12) is somewhat wider than the preceding one, and not as twisted. Proceeding forward as the former had backward past another branch [n. vestibulocochlearis?] (b in figs. 1, 2, ch. 2 bk. 4) of the the nerve of the fifth pair, to which it provides a passage, it transmits a vein [?] (n in the figure illustrating ch 14, bk. 3) that goes to the organ of hearing. But the nerve of the fifth pair is not entirely absorbed into those two branches: a larger portion [organum vestibulocochleare] (F in figs. 1, 2, bk. 4) of it surrounds and covers the cavity [c. tympanica] incised in the temporal bone somewhat like a membrane — not indeed the entire cavity but some surfaces of it, as if the larger portion of a nerve were divided into several membranes covering numerous regions of the cavity. Among the other surfaces of the cavity, some of which are flat and smooth and some porous like open pumice and sponge and irregular with considerable variation, one area (H) is round and smooth, surrounded by a bony circle that protrudes like a line. This is covered by a special portion (G) of the fifth nerve 16 as if by a small membrane. Near the outside of this circle, closest to the region of the ear, is placed an ossicle (I, N, O) braced and stabilized by two thin, sharp processes or legs; 17 the outer of these, nearer the ear, is shorter, thicker, and wider, and it ends in a sharp point.



Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 8 On the Ossicles That Enter Upon the Construction of the Organ of Hearing