10 



THE EXTERIOR OF THE HORSE 



to the respiratory passages, a short blind pouch or cul-de-sac in each, 

 formed by an inHection or in-folding of the common integument or skin. 

 This is placed outwardly and somewhat above the main channel, and is dis- 

 tinguished as the "false nostril". Its use is not well understood, but it would 



appear to be the remains of 

 an organ once essential in the 

 economy of the primitive horse, 

 but now probably of little phy- 

 siological importance. At the 

 time this observation is being- 

 made, an opening, al^out the 

 diameter of a hemp - seed 

 (c, fig. 7), may lie noticed at 

 the point of junction of the 

 infolded skin and the mucous 

 membrane. This is the orifice 

 by which the tears or super- 

 fluous moisture escapes from 

 the eyes, from which it is 

 carried by a long narrow tube 

 termed the nasal duct. When 

 seen for the first time it has been regarded by some as an ulcer, and we 

 have on two or three occasions been consulted as to its treatment. 



LATERAL SURFACES OF THE HEAD 



Fig. 7. — Examination of the Nostnl 

 a, True Nostril. b. False Nostril. e, Nasal Duct. 



The lateral surfaces, or sides of the head, are distinguished as 7'ight 

 and left. They are symmetrical, and the parts presented for considera- 

 tion are the same in each. Commencing from the top, we have^-1, the 

 external ear; 2, the temple; 3, the supra -orliit; 4, the orbital - ridge ; 

 5, the eye; 6, the cheek. 



The External Ear. — The ear is situated on the lateral aspect of 

 the poll, on the outer side of the forehead, and above the temjDle. It is 

 formed by a plate of cartilage or gristle invested by a covering of skin, 

 and rests on a cushion of soft fat. It is acted upon by no fewer than 

 twenty muscles, so arranged as to enable it to move in any direction in 

 c[uest of sound. Internally it is covered with long soft hairs, which serve 

 to prevent the entrance of insects and other foreign matter. 



The Temple (fig. 2). — The temple occupies a space on the side of the 

 head immediately beneath the ear and on the site of the articulation of 

 the lower jaw. In front it has the supra-orhit, or hollow of the eye; 



