THE ORBITS ^THE FACE. Q7 



VII. d), which are strengthened by several minute pillars 

 running from one plate to the other. 



THE ORBITS 



Are in the horse merely bony rings, one on each side ; not 

 osseous cups, as in man. The reader, however, at a glance 

 will perceive the place in which the eye should be situated, 

 and he will also discover numerous holes which serve the 

 purposes we have already alluded to ; save one placed near 

 the lower edge of the orbit, which allows of the secure loca- 

 tion of an important vessel called the lacrymal duct. The 

 bones of the face and of the skull unite to form the orbit, 

 which has no distinct bone allotted to it. 



The orbit is composed of eight bones, yet the two orbits 

 are formed by only fourteen bones ; because the ethmoid and 

 sphenoid, which are both single bones, enter into the forma- 

 tion of each orbit. 



The bones which enter into the composition of the orbits 

 are the sphenoid, squamous temporals, ethmoid, and frontals; 

 the lacrymal, malar, palatine, and superior maxillaries ; thus 

 four come from the face, and a like number from the cra- 

 nium. The cup of the orbit is chiefly made up by the 

 ethmoid, sphenoid, palatine and squamous temporals. The 

 rim of the orbit consists of the frontals, the lacrymals, the 

 malars, and the superior maxillaries. 



THE FACE. 



The face is principally formed by the protrusion of the 

 nose, which in this animal is carried so far as to form by 

 far the largest portion of the head. It has two large open- 

 ings (the nostrils), divided by a cartilaginous wall {Plate 

 VI. a), the septum; within the nasal passages are two 

 bones rolled round, and composed of very fine osseous net- 

 work ; upon these lie the vascular and highly sensitive 

 membrane of the nose, within which resides the sense of 

 smell (Plate VII. a, h). The nose, however, does not extend 

 from the skull to the most forward point of the head ; 

 behind the passages of the nostrils are situated several 

 comparatively large, vacant spaces, termed the frontal facial 

 (Plates W. and\\l. d), and maxillary sinuses. The use 

 of these spaces is not very well understood. Two things, 



f2 



