LOCOMOTION, 661 
The length and flexibility of their bodies must also be taken 
into account, rendering many legs necessary for support. We 
Fic. 501.—Representation of horse at walking pace (Marey). 
can only briefly refer to the method of locomotion well exem- 
plified by our domestic quadrupeds. However, the whole sub- 
ject will become plainer after a careful study of the cuts intro- 
duced in this chapter. 
Fie. 502.—Horse in act of trotting. In this, as in all the other paces, the body of the horse is 
levered forward by a diagonal twisting of trunk and extremities, the extremities describ- 
ing a figure-of-8 track (s u, rt). The figure-of-8 is produced by the alternate play of the 
extremities and feet, two of which are always on the ground (a, b). Thus the right fore- 
foot describes the curve marked ¢, the left hind-foot that marked r, left fore-foot that 
marked wu, and right hind-foot, s. The feet on ground in the present instance are left fore 
and right hind (Pettigrew). 
