210 THE HUMAN HCE1L. 



difference in the structure of the foot ? I really do noi 

 observe any as yet. 



Dr. B. Consider one moment, and you must see 

 how beautifully this arrangement conduces to facility and 

 security in walking. In setting down the foot in walking, 

 the heel first touches the ground, but being a little in the 

 rear of the leg, does not receive the direct weight of the 

 body. 



Emily. And thereby prevents a painful jar, which 

 would unavoidably take place, were the heel placed per- 

 pendicularly to the leg, or directly under instead of a 

 little behind it. 



Dr. B. Excellent you comprehend the tendency 

 of these mechanical provisions, as if it were no new sub- 

 ject. But it is hardly possible that any one who has 

 ever enjoyed that exhilerating exercise, dancing, should 

 not be struck with that admirable mechanism which 

 gives such grace and facility to the movements of the 

 foot. The heel having now touched the ground, the 

 weight of the body falling a little before, carries down 

 the rest of the foot by a gradual and steady motion. 

 The heel and toes now both touching the ground, some 

 force is expended in spreading out and separating to 

 their fullest extent, the pieces of this elastic arch. 



The human heel, by its great size and backward pro- 

 jection, has the advantage of affording a large space for 

 the attachment of the muscles, by which it is raised in 

 progression. Where it rests on the ground, it is covered 

 by nothing but skin and cellular tissue, whereas in the 

 brutes, various muscles and tendons pass over the heel, 

 in their course to the sole of the foot. 



Emily. This must effectually prevent them from 

 walking like man, since the muscles would be compressed 

 and prevented from action. But is it so in the apes 

 also ? The orang-ulang, you know, is said to walk like 

 man. 



Dr. B. They are taught to walk sometimes, but it 

 is always with feeble and tottering steps. Their foot is 



