THE OSSEOUS TISSUE. 163 



at 211; not including, however, in this calculation, the 

 teeth and the sesamoid bones. The former are separated 

 from the skeleton for reasons to be given hereafter, and the 

 latter are regarded as developments of the tendinous struc- 

 ture. 



The head has 22 bones, 1 frontal, 1 occipital, 2 parietal, 

 2 temporal, 1 sphenoid, and 1 aethmoid, constituting the 

 cranium ; while the 2 superior maxillary, 2 palatal, 2 ma- 

 lar, 2 nasal, 2 lachrymal or unguiform, 2 inferior turbi- 

 nated, 1 vomer, and 1 inferior maxillary, making 14, form 

 the face. 



The trunk has 56; 24 true or movable vertebrae, 1 

 sacrum, 4 caudal vertebrse or bones of the coccyx, 2 ossa 

 innominata, 12 ribs on each side, and 1 sternum. 



The hyoid bone stands by itself, at the upper part of the 

 neck, and consists of three, sometimes of five, pieces. 



The superior extremities have 68 bones, viz: 2 clavicles, 

 2 scapulas, 2 humeri, 2 radii, 2 ulnae, 16 carpal, 10 meta- 

 carpal, and 28 phalanges, forming the shoulder, arm, fore- 

 arm and hand, of both upper extremities. 



The inferior extremities have 64 bones, viz: 1 femur, 

 1 tibia, 1 fibula, 1 patella, 7 bones of the tarsus, 5 for the 

 metatarsus, and 14 phalanges for each lower limb, consist- 

 ing of the thigh, leg, and foot. 



The situation of the bones is either superficial or deep. 

 Examples of the former are seen in the tibia and clavicle, 

 which, excepting a little cellular and adipose structure, are 

 only covered by the skin; while the latter, as the thigh 

 bone, are some distance from the surface, and have a thick 

 covering of muscle. 



Bones present different degrees of density, varying even 

 in different parts of the same bone; those of the carpus and 

 petrous portions of the temporal bone presenting specimens 

 of the greatest density and compactness, while the long 

 bones have their bodies or diaphyses compact, and their 

 extremities loose or spongy. (Fig. 30.) 



Under the head of structure, to be presently noticed, we 

 shall see that the osseous fibres are brought either very 



