POSTERIOR EXTREMITY OF THE HEAD. 83 



A. The Poll or Nape (Fig. 19). 



Situation; Limits; Anatomical Base. The poll or nape 

 occupies the summit of the head. It is limited laterally by the ear 

 and the parotid region, anteriorly by the forehead, posteriorly by the 

 crest of the neck and the mane. 



This region, which corresponds anatomically to the occipito-atloid 

 articulation, has for its base, on the median line, the funicular por- 

 tion of the nuchal ligament, separated from the surface of the atlas by a 

 synovial bursa ; on each side are eight pairs of muscles disposed in several 

 layers. Over the side of the atlas, corresponding to the two foramina, 

 at the base of its transverse process, are the two principal blood-vessels, 

 the retrograde and occipi to-muscular arteries, separated from each other 

 by a space of about two inches. The skin which covers it is ordinarily 

 protected by the mane, which is usually cut to lodge the head-piece 

 of the halter or bridle. 



Diseases and Blemishes. The veterinarian must thoroughly 

 assure himself of the fineness and freedom from disease of this region ; 

 for, on account of the movements and the disposition of the muscles 

 into layers, filtration is favored, and all diseases in this location assume 

 an unfavorable aspect. 1 Wounds of the poll result sometimes from 

 a misfitting bridle or halter and from contusions, consequent on the 

 animal's rearing and striking the poll against resisting bodies. The 

 most common result of these is fistula with necrosis of the tendons, 

 nuchal ligament, and even the bones. This is extremely serious and 

 often fatal ; sometimes a cicatrix alone betrays the disease. A less 

 serious disease is a synovitis and dilatation of the above-mentioned 

 bursa. The swelling is usually bilateral. 



No one but the most ignorant would buy horses with such blem- 

 ishes without observing them. We know of instances in which the 

 hood was employed to cover the parts. An abnormal sensibility 

 of the poll is always indicative of a previous or now-existing disease, 

 which can be demonstrated by passing the hand over this region. 



B. The Parotid Region (Fig. 19). 



Situation; Limits; Anatomical Base. The parotid re- 

 gion, like the gland which forms its base, derives its name from its 

 proximity to the ear. It is limited above by the ear, below by the 



1 A. Goubaux, Note sur quelques lesions de la region de la nuque, chez le cheval (Arch, 

 veter., 1877, p. 137). 



