114 LECTURE III. 



turning horizontal motion which takes 

 place in this part of the vertebral column. 

 It also freely admits of motion from side 

 to side, but does not allow of it in any 

 considerable degree either forwards or back- 

 wards. Indeed had such motions been 

 permitted beyond a certain extent, the ab- 

 dominal viscera would have been injuriously 

 compressed by the ribs. Neither is much 

 motion, in this direction, requisite, because 

 we can carry forwards and backwards the 

 trunk of the body, by moving the pelvis 

 upon the rounded heads of the thigh bones. 

 The spinous processes of the loins extend 

 horizontally, so as not to interfere with one 

 another in the turning motion, but their 

 great breadth is prohibitory of extension 

 beyond a limited degree. 



The head is joined on to the first verte- 

 bra, (which, from supporting this globe on 

 its shoulders, is generally called the atlas,) 

 by two oval processes placed obliquely and 

 received into corresponding cavities in the 

 upper articular processes of this vertebra. 

 The form of the bones precludes any hori- 



