76 

 PART TIT. 



APPLICATION TO THE HIGHER ANIMALS. 



§ 79. Kegarding, then, the snake's contortions 

 as exemplifying the fundamental mechanics on 

 which the locomotions of quadiTipeds and man are 

 based, we observe in these higher animals — 



1st. — That the spine is not so pliable as in the 

 snake ; but that it is still a most elastic rod, made 

 up of httle blocks of bone, every two of which, in- 

 stead of having, as in the snake, a ball and socket 

 joint at their surfaces of co-adaptation, are, as it 

 were, threaded together throughout the two sur- 

 faces by an infinite number of short, strong elastic 

 filaments, which, rising from the whole surface of 

 one block, run into the whole corresponding sur- 

 face of the other, and form a solid elastic mass- 

 between them. 



2d. — That from a number of the vertebrse the 

 ribs have been removed. In fact, two such vacant 

 spaces exist, one at each end of the spine, and be- 

 tween them is the space to which ribs remain at- 

 tached. 



3d. — That, on this space, the motion and the 

 elasticity of the anterior ribs is very much re- 

 duced, in comparision with the posterior ones, and 



