LOCOMOTOR SYSTEM 631 



not yet reached the ground ; they are being advanced as far as 

 possible to the front, and to enable them to reach forward the 

 first hind-leg is snatched off the ground, and the animal is again 

 left standing on one hind-limb (4). The fore-legs now begin 

 their descent, and the one diagonal to the hind-limb on the 

 ground now makes contact (5). The horse's body is then sup- 

 ported on one fore and one hind diagonal legs. It is now the 

 turn of the fore-legs to make their stride, and to effect this the 

 body rotates over the fore-leg, and in doing so the hind-leg leaves 

 the ground. The animal is once more left on one leg (6). The 

 step is now made, both fore-legs being on the ground (7) ; the first 

 fore to reach the ground is now snatched up, and the horse is 

 left standing on one leg (8), which is the leading one, and within 

 the next fraction of a second the body is in the air. In Fig. 211 

 each of the important movements is shown in the horse. (1) is 

 the body in the air ; the manner in which the legs are collected 

 under it should be particularly noted ; the hind-limb which is 

 about to make contact is thrust as far forward as possible. In 

 (2) this limb has reached the ground ; in (3) its fellow has arrived, 

 and the step with the hind-legs taken ; in (4) the big reach 

 forward has occurred, to effect which one hind-leg has been 

 withdrawn ; in (5) the body is rotating over one fore-leg in order 

 to make its step ; at (6) this step has nearly been effected ; 

 at (7) the step has been taken, and the fellow fore-leg withdrawn ; 

 the body has now rotated over the leading leg at (8) , and when 

 this has been completed the spring into the air is made. The 

 gallop is an easier pace to follow than the canter ; there are 

 never more than two legs on the ground at any time, and the 

 greater part of the work is done with one leg. Briefly, a hind-step 

 with no support in front, a fore-step with no support from behind, 

 and a spring, constitute the essential features of the movement. 

 The only time when the hind-leg gives any assistance to the fore- 

 limbs is when one of the latter makes the forward reach prepara- 

 tory to taking its step. When a horse gallops, no matter how 

 fast, the fore-feet never extend in front of a vertical dropped 

 from the muzzle. In Fig. 212 is shown the track left on the 

 ground by a galloping horse. Muybridge, working with an 

 average thoroughbred in racing condition, galloping at the rate 

 of thirty-five miles an hour, obtained the following results : 

 Length of stride, 22 feet 10 inches, made up as follows : 



Fore -step . . . . . . 5 feet o inches. 



Hind-step . . . . . . 3 ,, 10 ,, 



Interval between hind and fore legs 7 ,, 6 ,, 



Spring 6 ,, 6 



With the ordinary horse, the strides of which vary from 15 feet 

 to 19 feet, the following results were obtained : 



