330 DR. C. 1''. SONNTAG ON TUE ANATOMY, 



surface of the zygoma, and the fibres converge to be attached to 

 the anterior two-thirds of the outer surface of the mandibular 

 ramus and coronoid process. Numerous large vessels (T.F.V) 

 ramify between the masseter and parotid gland and supply both. 

 The actual insertions are shown in text-fig. 28 B. 



The temporal muscle is large and powerful. It arises from the 

 entire temporal fossa from the external angular process of the 

 frontal bone in front, to about four centimetres behind the concha 

 and upwards to a point level with the supra-orbital crest. It 

 also arises from the temporal fascia which covers it. The fibres 

 are strong, coarse and mixed with tendinous bands ; they 

 converge to be inserted into the anterior border, point and 

 posterior border of the coronoid process (text-fig. 28 B). The 

 anterior part of the muscle is attached by muscle fibres to the 

 antei'ior border of the process, which is of considerable length. 

 But the posterior part is attached by aponeurosis to the back- 

 wardly-directed point and short posterior border. On the surface 

 of the muscle the zygomatico -facial artery i-amifies. A piece of 

 the aponeurotic insertion sweeps over the outer surface of the 

 coronoid. The deep tempoi-al vessels anastomose within it. The 

 action of the temporal muscle is described at length by Gratiolet. 

 The attachments of the masseter and tempoi-al muscles to the 

 mandibular ramus are shown in text-fig. 28 B. The iemporcd 

 fascia is attached to the temporal crest, external angular process 

 of the frontal bone, malar bone and upper border of the zygoma. 

 It is overlain by a considerable deposit of fat. It gives an 

 attachment to the fibres of the zygomaticus minor and extrinsic 

 muscles of the auricle. A few fibres of the temporal muscle arise 

 from it. 



The pterygoid muscles (text-fig. 29 A) are very similar to those 

 in Man, and all authors who have described them come to similar 

 conclusions. The relations of the various nerves in the pterygoid 

 region are the same as in Man, and the internal maxillary artery 

 (I.M.A) crosses the outer surface of the external pterygoid 

 (E.P.M) as in some human bodies. The veins, however, do not 

 form a large difl:use plexus, but consist of tributaries accom- 

 panying the large arteries and opening into an internal maxillary 

 vein. It divides into two veins which unite with the superficial 

 temporal vein. It communicates with the anterior facial vein 

 and with deep veins in the neck. No lymphatic gla,nds are 

 present in the pterygoid region, but much fat is present. It is, 

 therefore, evident that, with the exception of the characters 

 of the veins, the pterygoid region is essentially similar to that 

 in Man. 



The sterno-mastoid (text-fig. 30, S-M.M) arises by a long, 

 gently tapering, strong tendon from the inferior border of the 

 manubrium sterni, and it does not develop muscular fibres till it 

 reaches the neck. A few small tendinous bundles run from the 

 tendon of origin to the upper and mesial aspects of the sterno- 

 clavicular articulation, and strong: fascia unites the tendon to the 



