OSSEOUS SYSTEM OF MAMMALIA. 69 



the fore limbs are changed into oars, and every trace of hind limbs 

 has disappeared. To follow out, thoroughly, this part of the subject, 

 while yet limiting the observations on it to the class under review, 

 would occupy more space than the plan of this work will admit. It is, 

 however, so interesting, and so important a topic, that it would be un- 

 pardonable not to present something like a general outline of its principal 

 features. 



In all Mammalia, excepting the Cetacea, there are four limbs ; in 

 pairs, two anterior and two posterior ; and in all, Man excepted, these 

 limbs are organs of locomotion ; not, perhaps, of locomotion exclusively, 

 for, in many, the anterior pair, and, in some, both pairs, are constructed for 

 grasping and retaining ; and in others, again, the fore limbs are employed 

 as weapons, with which to strike : but these are not the sole purposes to 

 which the organs in question are destined ; on the contrary, though the 

 Monkey may seize with his hand, or grasp with his foot, though the 

 Squirrel may hold the fruit on which it is feeding, or the Lion dash the 

 Antelope to the ground with the stroke of his paw, still, in these cases, 

 and in every other, all the limbs are, in the strictest sense, organs of 

 locomotion. Not so in Man. Of the four limbs with which he is 

 endowed, the posterior, or lower pair, alone, are agents of progression ; 

 the anterior, or upper pair, being free ; and this freedom is connected 

 with Man's attitude, his upright bearing, his exalted intellect, and his 

 rank in creation. Thus, while the four limbs of brutes are simple organs 

 of locomotion, or, at most, are endowed with the mere power of grasping 

 or seizing a power only occasionally exerted while they are all 

 required to take a servile part in transporting the body from one 

 location to another, the arms of Man are free : their form, their pro- 

 portions, their parts, their situation, all accord with this exemption 

 from bondage. 



When the arm of Man is alluded to, in a general sense, every part, 

 into which the anterior extremity is divided, is included in that term ; 

 the whole, indeed, constitutes the organ, and no portion is independent 

 of another. It is usual, however, and convenient, to divide it into the 

 shoulder, the true arm, and the hand by which it is terminated : of 

 these parts the hand is the first which demands consideration, for, 

 because the hand is what it is, the remainder of the extremity is 

 modelled as we find it ; the arm is adapted to the hand, the hand is 

 essential to Man. Without the hand, the arm would be useless ; and 

 without the arm, the uses of the hand would be very circumscribed. 

 To the arm and the hand, then, as the type of the anterior extremity in 

 the lower Mammalia, as exhibiting the most complete degree of 

 development in all their parts, and that for duties and services of the 

 most important nature to the most important of all animals, considerable 



