146 



VETERINARY PHYSIOLOGY 



by the greater variations in the degree of pressure which are 

 produced by more powerful aerial waves, and how the greater 



ci 



ANT. HORN 



FIG. 73. Connections of Semicircular Canals with Central Nervous System, 

 Ves. R. t Vestihular root of eighth nerve sending fibres upwards to CB. 

 (cerebrum) and CBL. (cerebellum), downwards to the centre in medulla 

 oblongata (Med. ), and to Deiters' nucleus (N. Deit.), from which fibres 

 pass to the oculo-motor mechanism (N.vi.) and to the centres in the 

 anterior horn of the spinal cord. 



stimulation of the receptive centre in the brain will be 

 accompanied by a sensation of greater loudness. 



Pitch. A study of the structure of the cochlea seems to 

 show a mechanism well suited to afford a means of estimating 



