128 THE HOUSE I LIVE IN. 



body, a great number of the muscles are em- 

 ployed. In moving the hand alone, we use 

 nearly forty ; and in using the whole arm, not 

 much less, I presume, than one hundred. 



If you look on a skeleton, (see page 107 and 

 the frontispiece,) you see how the bones at the 

 joints project, and also how ragged the spine 

 and many of the flat bones appear. Now the 

 several hundred muscles of our frame fill up all 

 these spaces, cover the ragged bones, and pro- 

 duce that smooth surface which we see on a 

 healthy human body. 



The change which takes place is something 

 like that which would happen, if we were to 

 take some rather soft pliable substance, as 

 hemp, and not only wind it about all the side- 

 pieces of timber in a wooden house frame, but 

 extend it across from timber to timber, until 

 the whole were so filled up and rounded as to 

 appear like an even and regular surface, in- 

 stead of a broken range of pieces of timber, 

 with large vacancies between them. 



ABOUT FAT. But I must not leave the 

 impression that the muscles and tendons per- 

 form all the " filling up " of the human frame, 



