362 THE MECHANICAL FUNCTIONS. 



§ 9. Lisectivora. 



In the tribe of Insectivorous quadrupeds we meet with 

 several races which present singular conformations. In none 

 are these anomalies more remarkable than in the mole, an 

 animal which nature has formed for subterranean residence, 

 and whose limbs are constructed with a view to the rapid 

 excavation of passages under ground. The hands of the 

 mole, for its fore paws almost deserve that appellation, are 

 turned upwards and backwards for scooping the soil, while 

 the feet are employed to throw it out with great quickness. 

 These mining operations are aided by the motions of the 

 head, which is lifted with great power, so as to loosen the 

 ground above, and overcomie the resistances that may be op- 

 posed to the progress of the animal. That no impediment 

 might be offered to these motions of the head, the spinous 

 processes of the cervical vertebrae have not been suffered to 

 extend upwards. Large muscles are provided for bending the 

 head backwards upon the neck; and they are assisted by a 

 cervical ligament of great strength, which is generally in 

 part ossified. The muscles of the fore extremities are also 

 of extraordinary power. The scapula is a long and slender 

 bone, more resembling a humerus in its shape than an ordi- 

 nary scapula: the humerus, on the contrary, is thick, and 

 square, and the clavicle is short and broad. The radius and 

 the ulna are distinct from each other; the hand is very large 

 and expanded; the palms being turned outwards and back- 

 wards, and its lower margin being fashioned into a sharp 

 cutting edge. The carpal bones and the phalanges of the 

 fingers are very much compressed; but they are furnished 

 with large nails, which compose more than half the hands; 

 and they are expressly constructed for digging, being long, 

 broad, and sharp at the extremities. The sternum has a 

 large middle crest, and is prolonged at its extremity into a 

 sharp process, having the figure of a ploughshare, thus af- 



