THE SCAFFOLDING LEFT IN THE BODY. 91 



youth. It is difficult to imagine any other theory than 

 that of Descent which could account for all these facts. 

 That Evolution should leave such clues lying about is 

 at least an instance of its candor. 



But this does not exhaust the betrayals of this most 

 confiding organ. If we turn from the outward ear to 

 the muscular apparatus for working it, fresh traces of 

 its animal career are brought to light. The erection 

 of the ear, in order to catch sound better, is a power 

 possessed by almost all mammals, and the attached 

 muscles are large and greatly developed in all but 

 domesticated forms. This same apparatus, though he 

 makes no use of it whatever, is still attached to the 

 ears of Man. It is so long since he relied on the warn- 

 ings of hearing, that by a well-known law, the mus- 

 cles have fallen into disuse and atrophied. In many 

 cases, however, the power of twitching the ear is not 

 wholly lost, and every school-boy can point to some 

 one in his class who retains the capacity, and is apt to 

 revive it in irrelevant circumstances. 



One might run over all the other organs of the 

 human body and show their affinities with animal 

 structures and an animal past. The twitching of the 

 ear, for instance, suggests another obsolete, or obso- 

 lescent power — the power, or rather the set of powers, 

 for twitching the skin, especially the skin of the scalp 

 and forehead by which we raise the eyebrows. Sub- 

 cutaneous muscles for shaking off flies from the skin, 

 or for erecting the hair of the scalp, are common 

 among quadrupeds, and these are represented in the 

 human subject by the still functioning muscles of the 

 forehead, and occasionally of the head itself. Every 

 one has met persons who possess the power of moving 



