234 



THE SKELETON 



Cranium. — This is a box almost spherical, formed of eight 

 bones. The bone that forms the forehead is called the 

 frontal bone. Back of this, forming the top and part of 

 the sides of the box, are two large parietal bones; while 

 the back of the box is a single large bone, the occipital. 

 The occipital has a large openuig (the foramen magnum) 



thi'ough which the 

 brain communi- 

 cates with the 

 spinal cord. Two 

 smaller bones, the 

 temporals, and part 

 of the wedge- 

 shaped sphenoid, 

 complete the sides 

 of the box. In the 

 temporals are cavi- 

 ties which contain 

 the dehcate parts 

 of the ears. The 

 lower part of the 

 sphenoid bone, to- 

 gether with an- 

 other bone called 

 the ethmoid, form 

 the base of the 

 cranium and separate it from the face portion. On each 

 side of the foramen magnum are large facets which articu- 

 late with those of the atlas. 



The face bones. — The face is composed of fourteen 

 bones, of which t'welve are paired. One pair, the molars, 

 or cheek bones, form the base of the eye socket and the 



Pig. 93 — The skull; 1, frontal tone; 2, parietal 

 hone ; 3, temporal hone ; 4, sphenoid hone ; 5, eth- 

 moid hone ; 6, occipital hone ; 7, superior maxillary 

 (upper jaw) hone ; 8, malar hone ; 9, lachrymal 

 hone ; 10, nasal bone ; 11, inferior maxillary (lower 

 jaw) hone. 



