THE AUDITORY APPARATUS 



201 



eral receptors of the cochlea and semicircular canals are obviously 

 as dissimilar as are their functions, but the functional significance 



Medial geniculate body 



^Inferior quadrigeminate body 

 ^Nucleus of trochlear nerve 



Nucleus fastigii 



Nucleus emboliformis 



Dentate nucleus 



Lateral nucleus of 



vestibular nerve 

 _,Restiform body 



Dorsal nucleus ol 

 ^ cochlear nerve 

 ^Ventral nucleus of 



cochlear nerve 

 ,. Cochlear nerve 



Nucleus of lateral lemniscus 

 Medial longitudinal fasciculus --- 

 Lateral lemniscus^. 



Peduncle of superior olive 



Superior olivary nucleus 

 Trapezoid body 



Fig. 96. Diagram of the auditory and vestibular connections. Com- 

 pare Figs. 71, 77, and 86. The fibers of the cochlear nerve enter the ven- 

 tral and dorsal cochlear nuclei (the latter being termed the tuberculum 

 acusticum) at the lateral border of the medulla oblongata. The auditory 

 path now divides, one tract, the trapezoid body, passing ventrally through 

 the pons to enter the lateral lemniscus of the opposite side, and the other 

 passing dorsally through the acoustic medullary striae (stria? medullares 

 acustici) across the floor of the fourth ventricle and also entering the lat- 

 eral lemniscus. These fibers may be interrupted by synapses in the supe- 

 rior olives, the nucleus of the lateral lemniscus or the inferior colliculus 

 (inferior quadrigeminate body) before they reach the medial geniculate 

 body of the thalamus, or they may pass by these nuclei without connecting 

 with them. The fibers shown in the diagram as passing from the inferior 

 quadrigeminate body to the temporal lobe of the cerebral cortex are prob- 

 ably interrupted by a synapse in the medial geniculate body. (From 

 Morris' Anatomy.) 



of the sensory organs of the utricle and saccule is more uncertain. 

 The fact that fishes undoubtedly hear, notwithstanding their 

 lack of cochlea or any other receptors more complex than the 



