Quain's elements of anatomy . hat flattened. The saccule is situated in the lower and fore part of the cavity of the osseous Tm. 391. Fig. 391.—Membranous labyrinth and NERVOUS TWIGS DETACHED, MAGNIFIED (Breschet). k, facial nerve in the meatus auditoriusinternus ; I, anterior division of the audi-tory nerve giving branches, o, m, n, to theutricle and the ampulla of the superiorand external canals ; V, vestibular divisionof the auditory nerve, giving a branch, q, tothe saccule, another to the posterior am-pulla, q, and a third (r) to the cochlea, r ;a, b, c, ampuUffi of the superior, external,
Quain's elements of anatomy . hat flattened. The saccule is situated in the lower and fore part of the cavity of the osseous Tm. 391. Fig. 391.—Membranous labyrinth and NERVOUS TWIGS DETACHED, MAGNIFIED (Breschet). k, facial nerve in the meatus auditoriusinternus ; I, anterior division of the audi-tory nerve giving branches, o, m, n, to theutricle and the ampulla of the superiorand external canals ; V, vestibular divisionof the auditory nerve, giving a branch, q, tothe saccule, another to the posterior am-pulla, q, and a third (r) to the cochlea, r ;a, b, c, ampuUffi of the superior, external,and posterior semicircular canals respec-tively ; (I, the united part of the superiorand posterior canals ; e, the macula of theutricle ; /, the saccule. vestibule, close to the opening fromthe scala vestibuli of the cochlea, andis received into the hollow of thefovea hemispherica, from the bottomof which many branches of nerve enter it, and here there is a similarmacula in its waU. It also contains a small mass of THE MEMBRANOUS LABYEINTH. 451 The saccule is connected with the membranous canal of the cochleaby means of a short narrow canal, the canalis reuniens of Hensen (c. r.).There is also a minute canal, lined with epithehmn, which passes fromthe utricle along the aqueductus vestibuli to end blindly in a dilatedextremity (saccus endo-lymphaticus {)) on the posterior surface of thepetrous bone just below the orifice of the aqueduct and lying in thetissue of the dura mater. This canal is joined near its origin by a smalltube from the saccule, so that in this way the cavity of the saccule isbrought into communication with that of the utricle (Boettcher). Semicircijlae, Canals.—The membranous semicircular canalsare from one-third to one-fifth the diameter of the osseous tubes in whichthey are lodged, and are dilated into ampullse within the ampuUary en-largements of those tubes. In section they are oval or somewhat elliptical(fig. 392). At the ampuUte they ar
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