NATURAL THEOLOGY. 127 



sloping direction of the muscular fibres between the 

 ribs must operate in the same way. It must produce 

 a swifter motion than in any other position in which 

 the muscles could be applied. 



a, d, c, b, two ribs exhibiting a part of the intervening muscles, 

 passing obliquely from bone to bone ; by which direction of 

 the muscles a mechanical advantage is obtained as to the 

 quickness of the motion, for the purpose of respiration or 

 breathing. 



But there is a still more remarkable circumstance 

 to be noticed in the structure before us, which shows 

 the perfect foresight, and knowledge of mechanical 

 laws exhibited in our frame. Do you not perceive that 

 the sidelong action of these muscular strings a, b } 

 must tend, while they pull the ribs together, to give 

 a sidelong motion to the bones themselves, to cause 

 the rib a, d, to move to the right and the rib c, b, to 

 the left, and thus make them crowd against the 

 places where their ends are inserted ? 



A. It shows creative wisdom in our structure, 

 that this difficulty seems evidently to have been con- 

 templated. There are two sets of muscles employ- 



