56 THE HOUSE I LIVE IN. 



bones nearly into the shape of an ox-bow. 

 Why does it not produce mischief in some 

 way ? 



The gristle or cartilage between the verte- 

 bra? is very thick and strong, but at the same 

 time very yielding, like India rubber ; and it 

 is so constructed and placed, as will best allow 

 the spine to bend about in all the various ways 

 which even tumblers and rope-dancers could 

 wish. 



It is so elastic or springy, and also so readily 

 compressed, that people who stand or walk 

 much, are really a little shorter at night than 

 they are in the morning. Rest gives the 

 elastic cartilages time and opportunity to spring 

 back again into their place, while we sleep, so 

 that by the next morning we are as tall as ever. 



I ought, however, to say for it is a fact 

 that old people settle down a little, and are not 

 so tall as in middle age ; which is partly owing 

 to these cartilages yielding and yielding till 

 they become thinner. 



If the soft marrow of the spine, (which runs 

 down from the brain,) should happen to be 

 bruised or injured, there would be an end of all 



