68 



THE HORSE. 



They commu* icate with the cavities of the nose, and likewise with those 

 of the sphenoid, ethmoid, and upper jaw bones, and like the windings of a 

 French horn, increase the clearness and loudness of the neighing. They 

 are sufficiently evident at I in the following cut. 



SECTION OF THE HEAD. 



PRINCIPAL BONES, LIGAMENTS, ETC. 



a Nasal bone, or bone of the nose. 



b Frontal bone. The cavities or cells beneath are called the frontal sinuses. 



c Crest or ridge of the parietal bones. 



d Tentorium, or bony separation between the cerebrum and cerebellum. 



e Occipital bone. 



f Ligament of the neck, or ■pack-wax, by which the head is chiefly supported. 



g Atlas, sustaining or carrying, or first bone of the neck. 



A Dentata, tooth-like, or second bone of the neck. 



i Cuneiform, or wedge-shaped process, or base of the occipital bone. Between it and 

 the other porti m of the occipital bone, e, lies the great foramen or aperture through 

 which the prolon5,ation of the brain — the spinal marrow — issues from the skull. 



k Sphenoid, wedge-like, bone, with its cavities. 



I Ethmoid, sieve-like bone, with its cells. 



m Cerebrum, or brain, with the appearance of its cortical ana medullary sv oatance. 



n Cerebellum, or little brain, with its beautiful aborcscent appearance. 



A portion of the central medullary, marrow-like, substance of the brain, and the pro- 

 longation of it under the name of the crus cerebri, leg of the brain, and from which 

 many of the nerves take their origin. 



p Medulla oblongata, — the prolongation of the brain after the medullary substance oi 

 the cerebrum and cerebellum have united, and forming the commencement of th« 

 spinal marrow. The columnar appearance of this portion of the brain is repre- 

 seuted, and tlie origins of the respiratory nerves. 



