HANDS OF MAN. 135 



every respect, one rolls easily over the other, and the hand 

 is articulated with the moveable bone. In the lower extre- 

 mity these rolling motions would have introduced danger- 

 ous unsteadiness and insecurity. The foot therefore is ar- 

 ticulated with the tibia, which corresponds to the ulna 5 and 

 the fibula possesses no perceptible power of motion. 



The principal differences in the hand and foot occur in 

 the relation which the carpus and metacarpus, the tarsus and 

 metatarsus — the solid or resisting portions — bear respec- 

 tively to the phalanges of the fingers and toes, the flexible 

 portions of the members. The solid part of the hand is less 

 developed, and has far less volume than the analogous part 

 of the foot, on which the whole weight of the body in stand- 

 ing finally rests : the phalanges, on the contrary, which are 

 the principal agents in executing the functions of the hand, 

 are much longer and stronger than those of the toes, which 

 are not so essential to station or progression. The three pha- 

 langes of the middle finger equal in lengtli the length of the 

 carpus and metacarpus together ; while the respective propor. 

 tions of the tarsus and metatarsus and toes are about 5-6'ths 

 and l-6th. The parts of the foot and hand are disposed in- 

 versely in respect to their importance. The posterior por- 

 tion of the former, and the anterior of the latter, are of the 

 most consequence, and possess the most remarkable charac- 

 ters. The functions of the hand render it necessary that its 

 plane should be nearly continuous with that of the fore- 

 arm ; otherwise the radius could not guide it so precisely 

 to the objects in view. In the foot, the articulation is so 

 disposed, that its posterior part offers a powerful lever for 

 muscular agents, and a solid support for the mass above : 

 it is formed by a single bone of the foot, which adds to its 

 solidity. The metacarpus and metatarsus have a much 

 greater similarity to each other ; the latter is the more solid, 

 and ofters this principal difference : the metatarsal bone of 

 the great toe, by far the strongest of the whole, has scarcely 

 any motion on the tarsus, and is parallel to the others ; 

 while the corresponding bone of the thumb has a very consi- 

 derable extent of motion, and is anterior to the rest of the 

 metacarpus, supposing the palm to be turned directly for- 



