NATURAL HISTORY OF MAN. 29 



are wide and flat, thus affording a support to the touch, without 

 in the least interfering with its delicacy; finally, the whole hand 

 is capable of performing extensive rotatory movements. 



5. His vertical and biped position. In all the mammalia, with 

 the exception of man, the superior (anterior) extremities are ap- 

 plied to the same uses as the lower (or posterior; extremities, and 

 are always employed in locomotion, even when they are formed so 

 as to be used also as organs .of prehension ; in man, on the con- 

 trary, the lower extremities serve exclusively for station, (the 

 act of standing) and for locomotion, while the superior extremi- 

 ties remain free to act as the organs or instruments of prehen- 

 sion and of touch, a difference in itself sufficient to render them 

 fit to discharge their function with a degree of perfection far above 

 any thing seen in the monkey tribes and other mammalia. The 

 vertical position, which under every circumstance, is so very 

 favourable to man, has been considered by some authors, as not 

 being natural to him, and as being solely the effect of education ; 

 but this is an error. Even if he should wish to do so, man could 

 not habitually walk on his four extremities; of all the mammalia 

 the lower extremities of man are most favourably formed for sus- 

 taining the body, and every thing, in his whole organization, is 

 disposed for the vertical position. The foot is very large and so 

 fashioned as to rest nearly the whole of its lower surface upon 

 the ground ; the different bones of which it is formed are solidly 

 united one to the other, and the leg rests vertically upon it ; the 

 heel projects considerably behind this articulation ; the knee can 

 be completely extended, so that the weight of the body is trans- 

 mitted directly from the femur to the tibia; the muscles which 

 extend the foot and the thigh are remarkable for their volume 

 and strength ; the pelvis is much larger than in other animals, 

 which by separating the legs and feet from each other, increases 

 the extent of the base of support ; finally, the head is nearly 

 balanced on the trunk, because its articulation is placed beneath 

 the centre of its mass, and the eyes are directed forward, precisely 

 in the direction to be most useful to him. 



6. The horizontal position, on the contrary, would be extremely 

 inconvenient for man, for then his (hind) feet, short and almost 

 inflexible, and his very short thigh, would bring his knee against 

 the earth, while his anterior (superior) extremities would be too 

 flexible and too widely separated to afford him a solid support ; 



5. What is the position of man ? Could man sustain with ease, for any 

 considerable Itnjjth of time, any other than the vertical position? Why can 

 he not on all fours? 



6. Why would the horizontal position be inconvenient for man? 



