THE GAITS IN PARTICULAR. 551 



mencement and the end of the step the body rests upon one foot only 

 (1 and 1) ; that in its middle the base is diagonal (2), and during the 

 intermediary periods, tripedal (3 and 3). 



The instantaneous photographs of Lissa, 1 taken from a cavalry 

 horse going at a full gallop, confirm in all respects the principal results 

 obtained by M. Marey. As they are descriptive of a much greater speed 

 of the gait, and as the horse which furnished them was less held in check 

 and less trained than the preceding, they give rise to some differences 

 worthy of note. We have recorded them with the greatest care in the 

 notation of Fig. 242, which furnishes the necessary information. 



FIG. 242. Notation of the/wW gallop. 

 (From the instantaneous photographs of Lissa.) 



The duration of the stride is divided into twenty equal periods: the unipedal contacts (1 and 

 7), as well as the projection (8), each equal four; the tripedal (3 and 5) and the diagonal (4) each 

 equal two ; as to the bipedal (posterior, 2, and anterior. 0), they each equal one. 



Each foot remains in contact during seven periods, while its oscillation occupies thirteen. 



The most prominent factor of this gallop, when it is compared to 

 that which we have analyzed above, is that the beats A G, PD of the 

 second contact are no longer synchronous ; the posterior slightly pre- 

 cedes the anterior. In fact, the step is executed with four times. 

 This disassociation, which we will again find much more perceptible on 

 the race-course, and which presents a great analogy with that which is 

 manifested in the flying trot, is the result of the acceleration of the speed 

 as well as of new conditions of equilibrium. In the gallop of the 

 specially-dressed horse, the head and neck are more raised ; the general 

 attitude is higher ; the weight is thrown upon the posterior members. 

 Here, on the contrary, the two bipeds have a tendency to share the 

 weight of the body in an inverse manner, which horsemen express by 

 saying that the horse is upon his shoulders; 2 a certain independence of 

 action is established between the anterior and posterior bipeds, which 

 seem to gallop each on its own accord, the hind increasing its pro- 

 pelling force, the fore serving for the reception of the weight. 



1 G. Barrier, in Bulletin de la Soci&e' centrale de medeciue vteriiiaire, stance du 14 Fvrier, 

 1889. 



2 Lenoble du Teil, Revue des haras, Aout 15, 1889. 



