THE GAITS IN PARTICULAR. 



517 



Finally, when the trot is marched, as is seen most frequently in 

 that which is termed short, the phase of simple suspension is entirely 

 absent. The body never leaves the ground altogether, and the period 

 of exchange of contact gives rise to short quadrupedal bases, 1, 3, 5 

 (Fig. 211), which are interposed between the principal bases, 2, 4, 6, 

 formed by the diagonal feet. 



FIG. 211. Notation of the marched trot. 



Displacements of the Centre of Gravity and Reac- 

 tions. The centre of gravity, in the trot as in the amble, undergoes 

 two sorts of displacements, from side to side and from behind to 

 before. The latter give origin to reactions so much more forcible as 

 the gait is higher and more elongated. 



Concerning the lateral or transverse displacements, " since the body," 

 as Lecoq * properly says, " is successively supported by the diagonal 

 bipeds, the centre of gravity should always lie upon a point of the line 



FIG. 212. 



which unites the two members. If we suppose it to be at the point 

 C (Fig. 212) of the diagonal AB, we will find it at D upon the diag- 

 onal BA', when the left diagonal biped is on the ground, and it will 

 advance to E, upon the diagonal A'B f , when the right diagonal biped 

 will have completed the step. We see, therefore, that in the complete 

 step of the trot the line described by the centre of gravity, longer 

 than in the amble, forms less acute angles and approaches less the 

 borders of the rectangle of the members ; and that, consequently, a 

 more favorable condition for the equilibrium coincides with less ener- 

 getic muscular effort for an equal distance, since the expenditure of 



1 Lecoq, loc. cit., p. 354. 



