OUR ANCIENT RELATIVES 



three planes and capable of analyzing any move- 

 ment of the body into three directional components. 

 These instruments of precision communicate 

 their findings to the brain and form essential 

 partners to the instruments carried by the face. 

 Capsz/.^<?s 



^ 





jaw-s 



labial 



/lyoic^ a/^c/ y^^^<^^^'^^^ 



Fig. 7. Cartilaginous Skeleton of Head of Shark, Comprising 



Braincase, Primary Upper and Lower Jaws and 



Branchial Arches. 



The scaffolding or skeleton of the face (Fig. 7) 

 consists of three principal parts: first, the carti- 

 laginous capsules (olfactory, optic, otic) that sup- 

 port the paired organs of smelling, sight and 

 balancing; second, the cartilaginous trough and 

 box that enclose the brain; third, the cartilaginous 



upper and lower jaw-bars (palatoquadrate, Meck- 



17 



