204 ORDER CARNIVORA ; GENERAL CHARACTERS. 



adapted to the same purposes. We do not find such differences 

 in the structure of the anterior and posterior limbs, as we have- 

 seen in Man, the Bats, and the Mole ; all of them are equally 

 adapted for supporting the body on the ground, and for enabling 

 it to execute rapid and energetic movements upon the surface of 

 the earth, as in running, leaping, &c. The only exceptions to 

 this principle are among the aquatic species, such as the Otter 

 and Seal, in which we find an adaptation, more or less complete, 

 for residence in the water ; and the comparatively sluggish 

 Bears, a large part of whose life is passed among trees. The 

 muscular energy of the Carnivora is very great ; their respiration 

 and circulation very active ; and the demand for food, therefore, 

 (on the principles elsewhere stated, ANIM. PHYSIOL., 140), is 

 very constant. The rapid movement which they require for 

 pursuing a living prey is provided for in the structure of their 

 limbs, which are usually long, and moved by powerful muscles. 

 As these limbs have but little variety of movement (their action 

 in running and leaping being simply backwards and forwards), 

 a clavicle is but little required ; and this bone is usually very 

 small, not uniting the shoulder to the breast-bone, and is some- 

 times almost entirely deficient. In the Bears, however, whose 

 fore-limbs must be kept more apart, for the purpose of climbing, 

 and must be provided with strong muscles to draw them 

 together, we find a more complete clavicle than in most others 

 of the order. The two bones of the fore-arm still remain distinct, 

 and are capable of being in some degree rotated, one on the other, 

 as in Man. 



184. In regard to the arrangement of the bones of the hands 

 and feet, we find a marked variation in different species. In the 

 most active, and especially in those which have the greatest 

 powers of leaping, these bones are so connected with those above, 

 as to form nearly a continuous line with them ; and the animal 

 rests upon the points only of the toes. But in others, the hands 

 and feet are so united with the limbs above, that the animal 

 bears upon its palms and soles, thus acquiring a firmer footing, 

 but losing in activity. The animals which have the former con- 

 formation are said to be digitigrade ; those possessing the latter 



