222 THE EEASOK WHY. 



* Again he said unto me, Prophesy upon these bones, and say unto them, O jrt 

 dry bones, hear the word of the Lord." EZEKIEL xxxvu. 



935. Why are the bones of the arms and legs formed in 

 long shafts ? 



Because a considerable leverage is gained, by which, the advan- 

 tages of quickness of motion, and increase of mechanical power, 

 are secured. 



936. Why are the bones of the hands and feet numerous 

 and small ? 



Because the motions of the hands and feet are very varied and 

 complicated. There are no less than twenty-eight banes in one 

 hand and wrist; and about as many in a foot and ankle. To 

 these are fastened a great number of ligaments and muscles, by 

 which their varied compound movements are controlled. But for 

 the complexity of the mechanism of our hands and feet, our motions 

 would be extremely awkward, and many of the valuable mechanical 

 inventions which now benefit mankind, could never have been 

 introduced. The bones of the hands and feet are in number equal 

 to one-half of the whole of the bones of the body. 



CHAPTER XLVI. 



937. What are ligaments ? 



Ligaments consist of bands and cords of a tough, fibrous, and 

 'tmooth substance, by which the bones are bound together and held 

 in their places, allowing them freedom to move, and supplying 

 smooth surfaces over which they glide. 



938. W hy are the joints bound with ligaments ? 



Because the bones would otherwise be constantly liable to flip 

 from their places. 



