BONES Or THE SKULL. 



121 



The nead is almost 

 in equilibrium on the 

 condyles ( 1 6, 16), but 

 that portion situated 

 in front of the joint 

 is heavier than that 

 placed behind it, 

 hence it overweighs 

 the latter : this ne- 

 cessitates the presence 

 of more powerful 

 muscles in the pos- 

 terior region of the 

 neck, to maintain the 

 head erect upon the 

 spinal column; when 

 these become relaxed, 

 as in sleep, the head 

 falls forward upon the 

 chest. 



[ 246. The sphe- 

 noid and ethmoid 

 bones, Fig. 91 (1,2), 

 are wedged between 

 the cranial bones at 

 the base of the skull, 

 and may be said to be 

 common to the cra- 

 nium and the face. 



[ 247. The face is 

 formed by the union 

 of fourteen different 

 shaped bones, which 

 form five large cavi- 4 

 ties for lodging the 

 organs of vision, smell, 

 and taste. All the 

 bones of the face, the 

 lower jaw excepted, 

 are completely im- 

 moveable, and firmly 

 united to each other 



Fig. 90. 



