214 The Ixyves of the Moles, 



preservation of its existence; and it burrows equally for the 

 continuation of its species. And as it is our object, in this 

 notice, to describe its habits during the period of the propagation 

 of its kind, it may not be out of place to shew how the adaptation 

 of its organization to the purpose of burrowing illustrates the 

 above remarks. 



The anterior locomotive organs of the mole exhibit several 

 striking peculiarities of structure. The clavicle, which seems to 

 influence all the other modifications, deserves particular notice. 

 In man, the ape, and the bat, the clavicle forms a powerful arch, 

 which maintains the separation of the arms. In the bat especially, 

 where it is longer, it supplies the arm with a point for rotation 

 towards the head, during flight, — a position in which it is perma- 

 nent in the mole. With this view, the clavicle is contracted and 

 short, forming a trunk, whose length is less than its breadth. It 

 is supported anteriorly by the extremity of a vertical plate, 

 which comes from the sternum ; and in order that the bone, thus 

 shortened, may be preserved at a certain distance from the trunk, 

 the scapula is converted into an elongated bone, with a mere 

 rudimentary spine towards the posterior edge, and anterior to the 

 tubercle, which supplies the place of the acromion. Thus the 

 shoulder is placed anteriorly to the trunk, and at the same 

 time below, and far removed from the cervical vertebrae. 



The long sternum, which advances towards the head, carries 

 with it the shoulders. They do not rest on the thorax; and 

 thus the muscles moving the arm, which are of such a size as to 

 weigh more than all the rest of the muscular mass, are prevented 

 from exercising any injurious pressure. 



The shaft of the humerus is so small, that the bone may be 

 said to be composed of little more than two large extremities. 



The bones of the fore arm partake of the modifications of the 

 other parts. The radius is short and strong, and although not 

 anchylosed with the ulna, has no power of supination. The ulna 

 is a long trigonal plate, prolonged beyond the articular cavity, 

 and terminated by a strong transverse hook, into which the 

 olecranon is transformed. The curvature, and lateral position of 

 the humerus, and many concurring circumstances arising from the 

 disposition of the muscles, particularly of the panniculus carnosus, 

 raise the elbow higher than the shoulder, and draw the palm of 

 the hand backwards, a beautiful provision for throwing the earth 

 sidewise, during the animal's progression. 



The conformation of the hand is equally adapted to the habits 

 of the animal : It is strong, as broad as long, and the extremities 

 of the fingers are provided with nails, terminated by a sharp 

 margin, thickened externally, and provided internally with a 

 cutting edge. 



From this description, it will be evident that the anterior 

 member of the mole is ill adapted for uninterrupted progression. 

 The precautions which have been taken to separate and maintain 



