88 



THE HORSE IN MOTION. 



Wc have inserted two plates of the skeleton in the positions corre- 

 sponding with Figs. 6 and i 2 in order to enable the reader to under- 

 stand their action in the various movements, and by reference to Plate 

 II. he will be enabled to follow the descriptions in this chapter, and 

 the action of the various muscles that produce them, as described in 

 the previous chapters. 



Fig. 2. 



Fig. 2 represents the left fore foot upon the ground nearly under 

 the centre of gravity ; the centre of motion for the corresponding limb 

 has passed in advance of the foot, and a line drawn through these two 

 points would not be perpendicular to the surface of the ground ; or, for 

 brevity of expression, we will say he has passed the perpendicular. 

 The limb is being elongated or extended by the straightening of the 

 pastern joint and the joints at the elbow and shoulder; by these means 

 the support given by the muscles is continued. In this position there 

 is no muscular force exerted upon this limb below the knee. It was 

 shown at page 76 how the " back tendons," while the limb is in this 

 position, are converted into ligaments over which their muscles have 

 for the instant surrendered control, and in conjunction with the suspen- 

 sory ligament are supporting the weight of the body by their passive 

 resistance. As the body advances by its own momentum and the con- 

 tinual action of the great pectoral and dorsal muscles, the pastern joint 



