OSSEOUS SYSTEM OF MAMMALIA. 71 



of little use. Knowledge is not their sphere ; their wants, desires, and 

 pleasures are corporeal, not intellectual. 



It need scarcely be observed that, under the term, hand, is included 

 the part from the joint of the wrist to the point of the fingers, Its general 

 outline, the fingers being closed, approaches an oval : at the back part 

 it is inclined to be convex ; on the inner aspect, or palm, concave : it 

 is divided into a solid basal, and a digital, portion, comprehending the 

 fingers. 



The solid part of the human hand consists of the carpus, or wrist, 

 and an anterior portion termed the metacarpus. The metacarpus is 

 that upon which the fingers are immediately based. The convexity of 

 the external aspect of this solid portion, and its palmar concavity, have 

 been mentioned above ; this concavity, which certainly results, in the 

 first instance, from the arrangement of the bones, is rendered more 

 apparent, in consequence of the adductor muscles of the thumb and first 

 finger forming an elevation on one side, and the flexor muscles of the 

 little finger an elevation on the other, so as to bound a central depression. 

 The moveable part of the hand consists of the thumb and fingers : and it 

 will be well, before proceeding farther, to attend to their mutual rela- 

 tionship, and to their modes of action. 



It may be observed, then, that each finger, divided into three joints, 

 is capable only of being inflected towards or upon the palm, and of being 

 returned to its horizontal position. Such, however, is the muscular arrange- 

 ment, that no single finger can be fairly doubled down, though it admits 

 of partial inflexion ; as may be easily discovered, by trying to bring 

 each finger, separately, to a bent position against the palm, in the same 

 manner as when all are fairly doubled down. The stress of the fingers 

 is directly toward or against the palm ; not so that of the thumb, which 

 cannot be brought to press firmly against the palm, to which it merely 

 applies itself laterally. The position and the direction of motion allotted 

 to the thumb, render it antagonist to the fingers. To the tips of each 

 of these, either successively or all together, it can oppose its tip ; and, 

 when the fingers are doubled upon the palm, or folded around any 

 object, it presses obliquely upon them with great power, thereby ma- 

 terially adding to the firmness of the grasp. Man has, by far, the most 

 perfect thumb ; that of the Ape being so short as to oppose, with dif- 

 ficulty, the tips of the fingers : in some of the Simise, as will be seen 

 hereafter, this member is even wanting, or in a rudimentary condition ; 

 and in none of them is it fairly opposable to the fingers. 



It has been often asked, why the fingers are of unequal length ? a 

 question involving much in the answer. Ease and facility, in the ever- 

 varying and multitudinous performances which the fingers are called upon 

 to execute, are of the first consideration ; and to this point has Nature 



