178 THE HOUSE I LIVE IN. 



this large apartment, but only into a bag or 

 sack, called the lungs, which lies in it, and fills 

 it ; and is divided into two portions, one on the 

 right side and the other on the left. The pas- 

 sage from the doorway at the top of the throat 

 into the lungs, is at first considerably large, and 

 may be both felt and seen at the top of the 

 throat. It appears, at first view, to be a long 

 bony tube, but it is not so. It is made of firm 

 cartilage, almost as hard as bene. As soon, 

 however, as it gets fairly within the cavity of 

 the chest, it ceases to be cartilage, and becomes 

 nothing more than common membrane. 



The passage now divides into two, like the 

 trunk of a tree when it divides into two 

 branches. One of these smaller passages goes to 

 the right side of the lungs, the other to the left. 

 Soon each of these parts divide again ; then 

 those branches subdivide ; and it is not long 

 before the branches become as numerous as the 

 limbs of the thickest tree top you ever saw ; 

 and indeed much more so. And what makes 

 them appear thicker than they really are, is the 

 ten thousand little cells, like innumerable small 

 berries among the limbs of a tree or shrub, which 

 are everywhere interspersed ; for every one of 



