LECTURE III. 113 



or backwards, or any turning of one verte- 

 bra upon another; a form which allows 

 only of a motion from side to side, to 

 which, however, the ribs present an insur- 

 mountable obstacle. In the back, we find 

 the spinous processes sloping considerably 

 downwards, and absolutely locked together, 

 by a sharp ridge of one being received into 

 a groove of the other. We find, also, the 

 rib connected to the transverse processes, 

 so that every circumstance concurs to pre- 

 vent any motion, save that which results 

 from the elasticity of the intervertebral 

 substance. It seems, therefore, evidently 

 the intention of nature, to make the verte- 

 bral column, in the back, a fixed support 

 for the ribs to move upon. 



In the loins, we find the articular pro- 

 cesses very differently formed from what 

 they are either in the neck or back. The 

 descending ones are shaped like half an 

 oval, the convex surface of which is re- 

 ceived into a cavity of corresponding figure 

 in those which ascend, which form is admi- 

 rably adapted to admit of the suddenly 



