21 8 The Bird 



ated in the inner ear — which occupy the three planes of 

 space, — exercises a most important function, tliat of equi- 

 libration. They have been compared to the glass tube 

 filled with water and a shifting bubble of air, by centring 

 which a surveyor knows his instrument is perfectly level. 

 If these canals be injured or cut, the bird loses all 

 control of his actions ; if a certain one of the three canals 

 suffers, the bird moves its head rapidly sideways and 

 spins around in a circle; if another of the trio is by an 

 accident severed, the motion of the head is back and 

 forth, and the bird is compelled to execute forward som- 

 ersaults; when the third of these canals is cut the bird 

 continually falls backward. In reptiles and mammals 

 the same thing occurs, so the wisdom of Nature in pro- 

 tecting these delicate organs by a sheath of hard bone 

 is ver}' apparent. 



The Sense of Taste and Touch 



"The hands of birds being hidden in the feathers 

 which envelop the whole body, — their feet and their lips 

 and usuall}^ much, if not all, of their tongue, being 

 sheathed in horn, — these two faculties would appear to 

 be enjo3'ed in but small degree." 



The sense of taste is probably the least developed 

 of all. The nerves which find their way through the 

 pores of the bill and tongue are more properh' those of 

 touch than of taste, and this seems the more credible 

 when we consider the food of man}' birds, which is swal- 

 lowed entire, besides being so hard that nerves of taste 

 would be useless. Parrots and ducks, with their fleshy 



