CHAPTER III. 



MATERIAL OF THE FRAME. 



Structure of Bones. Shape of the Bones. 

 Particular Description. Growth of Bone. 

 Vessels of the Bones. 



You have already seen that the frame-work 

 of " the house I live in " consists chiefly of 

 bone. I think, therefore, that before we go 

 any farther, I ought to tell you how bones are 

 constructed, and of what substances they are 

 made. 



STRUCTURE OF BONE. Sticks of timber 

 are evidently full of little holes ; for if you 

 take a piece of wood, of several kinds which I 

 could mention, and put your mouth at one end 

 of it, and blow hard, you can force air through 

 it. This shows'that there are little holes in it, 

 running lengthwise, all the way through. If 



