LOCOMOTION. 



55 



are developed, this intimate relation between the mus- 

 cles and the vertebra 

 goes on diminishing. The 

 muscles are more con- 

 centrated about the limbs, 

 where the greatest amount 

 of muscular force is re- 

 quired. For this reason, 

 the largest masses of flesh, 

 in the highest vertebrates 

 are found about the shoul- 

 ders and hips ; while in 

 the fishes, they are con- 

 centrated about the tail, Fig. so. 

 which is the part on which they principally depend for 

 motion. 



SECTION II. 



OF LOCOMOTION. 



163. One of the most curious and important applications 

 of this apparatus of bones and muscles, is that for LOCOMO- 

 TION. By this is understood the movement by which an 

 animal passes from place to place, in the pursuit of pleasure, 

 sustenance or safety, in distinction from those motions 

 which are performed equally well while stationary, such 

 as the acts of respiration, mastication, &c. 



164. The means which nature has brought into action to 

 effect locomotion under all the various circumstances in 

 which animals are placed, are very diversified ; and the 

 study of their adaptation to the necessities of animals is one 

 of the highest interest in a mechanical, as well as in a 

 zoological point of view. Two general plans may be noticed, 



