496 THE MECHANICAL FUNCTIONS. 



gressive movements, by the variations she has 

 introduced into the comparative lengths of the 

 several parts of the trunk, and the size and mo- 

 bility of the extremities. Of all the large ani- 

 mals, the Lion has been constructed with the 

 finest proportions for conferring both strength 

 and activity. The mass of his body is supported 

 more by the fore than by the hind extremities. 

 In walking, the lion takes long strides, and exhi- 

 bits strongly the lateral undulations of the trunk. 



Quadrupeds having a very long, or a very 

 massive body, or whose limbs are short, and 

 nearly of equal height, are incapable of ad- 

 vancing by a gallop, or at least cannot sustain 

 this pace without a painful effort, and never but 

 for a short time. The Tiger, which has a longer 

 body than the lion, gallops with less facility ; 

 and runs chiefly by an acceleration of its walk- 

 ing pace. It excels principally in the vigour 

 and extent of its bounds ; for which it is admi- 

 rably qualified by prodigious power of its mus- 

 cles, enabling it to spring forwards upon its victim 

 with an impetus which nothing can resist. 



The speed with which a quadruped is capable 

 of advancing depends more on the disposition of 

 the muscles and the extent of the articulations, 

 and more especially on the power of the ex- 

 tensors of the hind extremities, than on the form 

 of the body. Great length and muscularity in 

 the hind legs are generally attended with con- 



