136 THE FAIRY-LAND OF SCIENCE. 
All this is what is going on outside your ear, but 
what is happening in your ear itself ? How do these 
blows of the air speak to your brain ? By means of 
the following diagram, Fig. 33, we wil1 tr 7 to under ' 
stand roughly our beautiful hearing instrument, the 
ear. 
Fig. 33- 
a, Concha, or shell of the ear. b c, Auditory canal, c, Tympanic 
membrane stretched across the drum of the ear. E, Eustachian tube. 
d, e, f, ear-bones : d, the hammer, malleus ; e, the anvil, incus ; f, the 
stirrup, stapes. L, Labyrinth, g, Cochlea, or internal spiral shell. 
A, One of the little windows ; the other is covered by the stirrup. 
First, I want you to notice how beautifully the out- 
side shell, or concha as it is called (a), is curved round 
so that any movement of the air coming to it from 
the front is caught in it and reflected into the hole of 
the ear. Put your finger round your ear and feel how 
the gristly part is curved towards the front of your 
