158 THE HOUSE I LIVE IN. 



spread out, the shape of which everybody 

 knows ; and a passage in the middle, leading 

 into the head. 



The external ear, which we see, is made 

 of gristle or cartilage, covered with the skin. 

 It is concave, for the collection of sound. 

 Such is the curious structure of the eye, that 

 the rays of light, from all directions, are col- 

 lected into a very small point in the hack part 

 of it ; and in like manner, such is the structure 

 of the external ear, that sound is collected by 

 it toward the passage, in the centre. 



This passage is lined by a membrane just 

 like the skin, except that it is a little thinner, 

 the little bottles, or oil glands, are more numer- 

 ous, and the oil which they furnish is more 

 bitter. What is called the ear-wax is this 

 oil, dried and accumulated in large quantities. 

 Sometimes it has been known to accumulate in 

 such hard masses and of such a size as to make 

 people deaf. There was lately a case of this 

 kind in Boston. Both ears were in this condi- 

 tion, but one was much worse off than the other. 



This oil or wax is supposed to have been 

 made bitter, to keep flies and other insects from 

 getting into the ear. These insects dislike such 



