LATERAL FACES OF THE HEAD. 41 



All authors who have described this region have confounded it with 

 the superior lip, whose organization is entirely different. They have, 

 therefore, erred anatomically in saying that it has an extensive nerve- 

 supply, and physiologically none the less seriously in considering it as 

 the principal organ of touch in the horse. The superior lip fulfils the 

 latter role. It follows from this that we will describe neither beauty 

 nor defect of this region, excepting that it should be large as an index 

 of the respiratory functions. 



It is more important to assure ourselves that it is exempt from blemishes. 

 When they exist, they are nearly always the result of falls which the animal has 

 received. It is necessary, then, to examine with care the state of the incisor 

 teeth, the lips, the gums, and the plumb-line of the extremities, to determine as 

 nearly as possible whether the blemishes resulted from an accident or from a 

 weakness of the fore limbs, the effect of usage. They are never produced by the 

 application of the twitch, a means of torture employed to divert the attention 

 of the animal, and which can only be placed upon the superior lip, whatever 

 precaution in this respect be taken. 



CHAPTER II. 



LATERAL FACES OF THE HEAD. 



A. The Ear (Fig. 19). 



Situation ; Limits ; Anatomical Base. The ear is situated 

 at the superior extremity of the lateral face of the head, to one side 

 of the forehead and the dependency of the mane known under the 

 name of forelock, in front of the poll, above the parotid gland and 

 behind the temple. 



Anatomically, this region is easily visible, and has for its base the 

 conchal and scutiform cartilages. These give attachment to ten pairs 

 of muscles which endow the ear with movements either general or 

 partial. The former carry it backward, outward, forward, inward, 

 and rotate it on its adipose cushion. The latter (mastoido-auricularis) 

 are destined to move the concha so as to adjust the volume of air in 

 the auditory chamber (hiatus) to sounds of different intensities. 



Diverse beauties are recognized in this organ which are depend- 

 ent upon its length, thickness, situation, direction, and movements. 



1. Length. As Bourgelat has remarked, some prefer a long ear, 



