CREATION BY EVOLUTION 



the wrist bones — is the longest and corresponds to the long 

 bone in the human hand that extends from the wrist througli 

 the region of the palm to the base of the middle finger. If 

 this single long bone in the horse is examined it will be found 

 to. have on either side of it delicate splint bones, which 

 lie in the flesh of this portion of the horse's legs but which 

 support no parts in particular (Fig. 5). In position these 

 two splint bones correspond to the long bones of our second 

 and fourth digits, but they are not continued as such in the 

 foot of the horse. The splint bones of the horse's foot are 

 obviously remnants of other digits and are in the strictest 

 sense of the word vestigial organs. 



Turning to man we find him no exception to the rule 

 that vestigial organs are abundantly present in the organiza- 

 tion of animals. The external ear of the human being is a 

 complicated fold of skin supported within by cartilage or 

 gristle and occupying a fixed position on the side of the head. 

 So far as hearing is concerned it is probably an organ of 

 no great value. At least its occasional loss works no serious 

 detriment to the hearing of its owner. But in listening for 

 very faint noises we commonly extend the ear by holding 

 a hand behind it, so that this organ probably serves some- 

 what as a collector of sound. 



Notwithstanding the functional insignificance of the 

 human external ear, this organ is provided with a rathei 

 remarkable group of muscles (Fig. 6). Extending from 

 what may be called its root outward to the surface of the 

 head are three considerable muscles, whose respective actions 

 would be to bend the ear forward, upward, and backward. 

 In addition to these muscles the surface of the ear proper 

 has upon it six or more small muscles whose contractions 

 would change slightly the form of the ear. All these muscles 

 are well developed in the ears of certain lower animals, 

 such as the horse and the dog, in which the three extrinsic 



[40] 



