144 



SKELETON OF THE PIG 



over the roots of the molar teeth and overhangs the concave lower part. The 

 alveolar border is thin in front and widens behind; it does not follow the axis of 

 the ramus, but runs nearly straight and produces the marked overhang noted above. 

 There are seven alveoli for the lower cheek teeth, which increase in size from before 

 backward. The first is small, not always present in the adult, and is separated by 

 short spaces from the second and the canine alveolus. The vertical part is rela- 

 tively wide above. The condyle is convex in both directions, wide in front, narrow 

 and declivitous behind. The very small and thin-edged coronoid process is not 

 quite so high as the condyle, from which it is separated by a very wide notch. The 

 mandibular foramen is large. The two halves of the bone unite soon after birth 

 in the improved breeds. 



The body of the hyoid bone is broad from before backward, short transversely, 

 and bears on its ventral aspect a very short pointed lingual process. The thyroid 

 cornua are wide and curved, concave and grooved dorsally; their ends are attached 

 to the thyroid cartilage of the larynx by rather long bars of cartilage. The small 

 cornua are short, wide, and flattened dorso-ventrally ; they are attached to short 

 bars which project from the junction of the body and thyroid cornua. The middle 



cornu is a little longer than the 

 small cornu, but is relatively 

 slender; it is largely cartila- 

 ginous in the young subject 

 and does not ossify at either 

 end. The great cornu is a 

 very slender rod, slightly en- 

 larged at either end ; the upper 

 extremity is attached to the 

 hyoid process of the temporal 

 by a rather long and wdde bar 

 of cartilage. 



Fig. 112. — Mandible of Pig. 

 a, Body of mandible; b, horizontal part of ramus; /, vertical 

 part of ramus; c, interalveolar border; c', interval between canine 

 and corner incisor; c" , interval between first and second premolars; 

 d, mental foramina; e, vascular impression; g, coronoid process; 

 h, condyle; i, sigmoid notch; A-, mandibular foramen; 1-7, cheek 

 teeth, S, canine tooth; 9, 10, 11, incisors. (Ellenberger-Baum, 

 Anat d. Haustiere.) 



THE SKULL AS A WHOLE 



The length and the profile 

 contour vary greatly in dif- 

 ferent subjects. Primitively 

 the skull is long — especially in 

 its facial part — and the frontal 

 profile is almost straight. The condition is very pronounced in wild or semi-feral pigs, 

 and exists also in the improved breeds during extreme youth. IVIost of the latter are 

 decidedly brachyce])halic when fully developed; the face is "dished" in a pro- 

 nounced fashion. The frontal region slopes sharply upward, and the nasal region 

 is shortened, and in some specimens even distinctly concave in profile. The supra- 

 orbital foramina are about midway between the orbital margin and the frontal 

 suture. The supraorbital grooves extend forward from the foramina to the nasal 

 region and turn outward and downward toward the infraorbital foramina over the 

 ridges which separate the nasal and lateral regions. 



The lateral surface is triangular when the mandible is included. The tem- 

 poral fossa is entirely lateral and its long axis is almost vertical. It is bounded 

 above by the occipital crest, behind by the temporal crest, in front by the parietal 

 crest, and is marked off from the orbital cavity by the supraorl^ital process and a 

 curved crest which extends from it to the root of the pterygoid process. The 

 zygomatic arch is strong, high, and flattened from side to side. Its root is notched 

 above and bears a projection below. It curves sharply upward behind and forms 

 a pointed recurved projection above and in front of the external auditory meatus. 



