260 



MOVEMENT 



detail with absolute accuracy. Thus the diagrams 

 182, 183, and 184 represent almost on the same scale 

 the movements of the different segments of the lower 



Fig. 182. — Movement? of a uiai 



in executing a step. 



limbs during the execution of half a step in the case 

 of a man, a horse, and an elephant. 



These diagrams demonstrate that the same segment 

 can execute different movements, just as it may be of 

 different length and different shape in the three types 

 under comparison, and that the same segment may 



Fig. 183. — Movements of the various segments of a horse's hind leg in executing a 



step. 



play a variable part in the flexion and extension of the 

 limb. 



We can now understand why the muscles which act 

 upon these bones present, in different species of 

 animals, differences in length and volume, although the 



