38 PRINCIPLES OF VETERINARY SCIENCE 



The malar bones are situated below the lacrimal bones and 

 correspond to the cheek bones of man. 



The turbinated bones, four in number, two on each side, 

 divide the nasal cavity into three passages. The bones are very 

 delicate and are covered in the living animal with mucous mem- 

 brane. The anterior extremity of each bone is prolonged to the 

 nostril by a plate of cartilage. 



The vomer is a single bone placed in the median plane. It is 

 grooved for the reception of the septal cartilage of the nose. 



The mandible, or lower jaw, is the largest bone of the face. It 

 is composed of a body and two branches. The body is the 

 anterior part, which lodges six incisor teeth. Behind these, in 

 the male on each side, is an alveolus for a canine tooth. The 

 branches diverge backward from the body to form the submaxil- 

 lary space. Each branch has a horizontal and a vertical part and 

 presents two surfaces, two borders, and two extremities. Both 

 surfaces of the horizontal part are slightly convex and smooth. 

 The superior border has six alveoli for the lower molar teeth; the 

 inferior border is thick and rounded in the young animal, but 

 becomes thin and sharp in the old. The vertical part is wide and 

 thin with external and internal surfaces that are concave and 

 rough to lodge the powerful muscles of mastication. The anterior 

 extremity joins the body, while the posterior presents an articular 

 condyle for the temporal bone. A thin, flat process projects 

 upward from the front of this articular surface. 



The hyoid bone is situated between the vertical parts of the 

 mandible. It supports the root of the tongue, the pharynx, and 

 the larynx. 



B. The trunk is composed of the vertebral column and the 

 thorax. 



The vertebral column is made up of five groups of vertebrae, 

 designated cervical, thoracic, lumbar, sacral, and coccygeal in 

 the order of their occurrence. Each group has a typical number 

 of segments as shown in the following formula: 



Individual vertebra in each group closely resemble each other. 

 AH the vertebrae are constructed on a common plan, so a descrip- 

 tion of a typical member will serve as a basis, and any marked 

 deviation from this plan will be noted afterward. 



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