BONES AND HEAD. 



11 



Development. —Bones develop either in cartilage or membrane. 

 The long leg bones develop from cartilage ; the flat skull bones 

 develop from membrane. 



Composition. — Normal bone of mature animals contains about 

 one-third animal matter, and two-thirds mineral matter. Animal 

 matter gives elasticity, the mineral matter gives firmness and 

 strength. 



FIG. 5. TWENTY YEARS, LOWER JAW. 



A 



B 



FIG. 6. GRINDING SURFACES OF MOLARS. 

 Horse six to seven years old. A, right hand superior molars; B, left hand 

 inferior molars. 



Groups. — Bones are divided into the following groups for 

 study: Head, spinal column, sternum, ribs, front limb, hind limb. 



Head. — 26 bones; cranium 9, hyoid 1, face id. 



Cranium 9; occipital 1, frontal 2, parietal 2, temporal 2, eth- 

 moid 1, sphenoid 1. 



Hyoid 1. 



Face 16; superior maxillary 2, inferior maxillary 1, premax- 

 illary, 2 ; palate, 2 ; malar, 2 ; lachrymal, 2 ; nasal, 2 ; vomer, 1 ; in- 

 ferior turbinated, 2. 



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