182 THE ANATOMY OF THE HORSE. 



A reference to Plate 29 will enable the dissector to identify these 

 muscles. 



The Panniculus Carnosus does not form a continuous muscle on 

 the face. It consists of disconnected bundles developed in the sub- 

 cutaneous fascia. It is best developed over the masseter muscle, 

 where it is continuous over the edge of the inferior maxilla with 

 the same structure in the parotideal and intermaxillary regions. On 

 the cheek a few bundles reach the angle of the mouth, in whose 

 retraction they assist. 



Below the rim of the orbit there is found a thin layer of pale mus- 

 cular fibres and intermediate fascia, which may be viewed as part 

 of the facial panniculus. It wrinkles the overlying skin. This is 

 the lachrymal muscle of French authors, and the inferior 'palpebral 

 muscle of Leyh. 



The Levator Labii Superioris Aueque Nasi (Plate 29). This 

 muscle has a narrow, thin, and aponeurotic origin from the frontal 

 and nasal bones, below and internal to the orbit. It passes over 

 the levator labii superioris proprius ; and, widening as it descends, 

 it divides into an anterior and a posterior branch, between which 

 the lateral dilator of the nostril emerges. The anterior is the 

 larger branch, and it passes beneath the last-mentioned muscle to 

 end in the outer wing of the nostril and the adjacent part of the 

 upper lip. The posterior branch is inserted into the angle of the 

 mouth. 



Action. — To dilate the nostril and elevate the upper lip by its 

 anterior branch ; to raise the angle of the mouth by its posterior 

 branch. 



The Levator Labii Superioris Proprius (Plates 29 and 30, and. 

 Fig. 21). By its superior extremity, which is rounded and fleshy, 

 this muscle takes origin below the orbit, from the malar and superior 

 maxillary bones Becoming narrower and thicker, it passes down- 

 wards and forwards beneath the last-described muscle, whose direction 

 it crosses. Appearing in front of this muscle, it lies on the £ilse 

 nostril ; and here its muscular portion is succeeded by a narrow 

 tendon, which passes inwards above the superior commissure of the 

 nostril to gain the upper lip. In the lip it passes over the transverse 

 dilator of the nose; and, approaching the muscle of the opposite 

 side, it becomes united to it across the middle line by an intermediate 

 fascia, and is inserted into the texture of the upper lip. 



Action. — Acting together the right and left muscles elevate the 

 upper lip vertically. When the muscle of either side acts singly 

 the lip is raised and inclined towards that side. ' 



The Dilatator Xaris Lateralis. (Doubtfully the homologue of 

 the caninus of man) (Plate 29). This muscle is triangular in form. 



