ANATOMY OF THE HORSE. 35 



form extremities are contracted and closed ; and give origin, in 

 the recent subject, to two cartilaginous productions, which project 

 into the chambers of the nose. 



Particularities. — These bones are four in number : two supe- 

 rior, and two inferior. They are thin, and porous or spongy in 

 their texture ; brittle, and yet possessing sufficient elasticity to 

 enable them to resist considerable pressure, and withstand, without 

 fracture, any ordinary injury. 



Difference. — The superior bone exceeds in volume the inferior, 

 and makes its convolution from below, its upper border being 

 attached ; whereas, the reverse is the case with the inferior one. 



Connexion. — The superior bone is connected, above, with the 

 ethmoid; and laterally, with the nasal bone. It contributes to the 

 formation of the anterior part or floor of the frontal sinus. The 

 inferior turbinated is fixed to the superior maxillary bone. 



THE VOMER. 



Situation. — Along the floor of the nose, preserving the median 

 longitudinal line dividing the chambers. 



^i^w/e.— Elongated : posterior portion, broad, quadrilateral, 

 and flattened ; anterior, narrow, grooved, and lengthened. 



Division. — Into two extremities and two borders. 



Extremities. — The Posterior or broad part exhibits a 

 lower surface, somewhat convex, which is smooth and free ; an 

 upper sujface, somewhat concave, which embraces and almost 

 conceals the body of the ethmoid bone ; a superior crescenlic bor- 

 der, between which and the ethmoid is a narrow hiatus, giving 

 passage to some blood-vessels and nerves to the septum narium ; 

 two lateral borders, united with the palate bones ; and four cornua 

 or projecting acuminated ends, the two superior articulating with 

 the sphenoid bone, the inferior with the palate bones. The an- 

 terior extremity is broader than other parts of the grooved 

 shaft, in consequence of being flattened above and below ; it 

 reaches as far forward as the palatine processes of the anterior 

 maxillary bone. 



Borders. — The superior presents a long narrow chasm or 

 groove, deeper posteriorly than anteriorly, which receives the car- 

 tilaginous partition called the septum narium. The inferior 

 border is semi-cylindrical, and presents a posterior part, smooth 

 and free from any connexion ; and an anterior, which denticulates 

 with the palatine processes of the superior maxillary bone. 



Connexion. — With the ethmoid and sphenoid, and with the 

 superior and anterior maxillary and palate bones. 



