106 ANIMAL MKCIIAMSIU. 



In this series of movements the ear lias, therefore, dis- 

 tinguished three sounds, at nearly equal intervals. The first 

 sound is produced by a hinder foot, the second by a diagonal 

 biped, tin; third by a fore-foot. Between the single impact of 

 the fore-foot, which constitutes the third sound, and the first 

 brat of the pace which follows, reigns a silence whose dura 

 tion is exactly equal to that of the three impacts taken 

 together; then the series of movements recommences. 



By the inspection of the curves, we see that the pressure 

 of the feet on the ground must be more energetic in tin- 

 gallop than in the other paces already represented, for the 

 height of ihe curves i.s evidently greater than for the trot, 

 and especially so as compared with the walk. In fact, the 

 animal must not only support the weight of its body, but give 

 it violent forward impuU.cs. The greatest energy seems to 

 belong to the first impact. At this moment, the body, raised 

 for an instant from the ground, falls again, and one leg 

 alone sustains this shock. 



Fio .V, 0:illn]i in tliroo-tiinc (A) imlicition of tlircu-time. B. indication 

 of I lie iiiinii'cr of ti'et wliich form tlie support ot tbe body at cacti instant 

 of tlic gallop in three timo. 



If we wish to take account of the successive pressures which 

 sustain the body during each of the steps in the gallop, we 

 have only to divide the duration of this pace into successive 

 instants in which the body is sometimes supported on one or 

 on several feet, and sometimes suspended. The notation (fig. 

 50) allows us to follow in (A) the succession of impacts, and 

 shows in (B) the succession of the limbs wliich cause these 

 pressures on the ground. 



II wo wish to ascertain what are (he rr-iictimis produced nt 

 the withers, we see them represented in lig. '>'> Cupper line K 

 We find an undulatory cle\ ; uioii, \\hich lasts all the tune 



