458 THE EXTERIOR OF THE HORSE. 



Short- and straight-jointed when it approaches the vertical line mn. 



Having studied the last two defects in connection with the pastern, 

 we will not return to them here. We will speak only of the incon- 

 veniences which follow from the first two conformations. 



Horse Under Himself Behind (Fig. 163 [2]).— The direct axis 

 of the member in this case is oblique downward and forward, instead 

 of being vertical. This disposition diminishes the aptitudes of the 

 column as a support and favors its falling backward, borne down as it 

 is by the force of the body- weight acting \\\nm tiie point e in the di- 

 rection ed. There follows from this a weakened equilibrium, causing 

 the horse to slip forward, to be hesitating in his steps, and the bony 

 segments to be flexed, two causes which increase the strain on the ex- 

 tensor muscles, the tendons, and the ligaments from greater efforts. 



Besides, the metatarsus being situated obliquely under the tibia, the 

 tibio-tarsal angle acquires a state of defective closing, characterized by 

 the angular y elbowed hock, which renders this articulation liable, as we 

 have seen (page 266), to show the effects of use the earlier and more 

 seriously in proportion as the canon is more inclined under the 

 body. 



The foot also coming nearer to the centre of gravity, the base of 

 support is shortened to the detriment of the stability, while the over- 

 burdened posterior limb has not the same freedom of movement, 

 which augments its work and favors its chances of being blemished. 



Finally, this vicious direction is also detrimental to the speed of 

 the gaits, in consequence of the two following reasons : 



The first is dependent on the shortness of the stride, because the 

 member, advanced for a smaller distance than in the normal state of 

 the extreme limit of its forward oscillation, is incapable of passing 

 over much ground. 



The second consists in the loss of time determined at each step by 

 the vertical displacements of the croup, the member being able to com- 

 municate an efficacious impulsion only on condition of having attained 

 that particular degree of extension which makes it underpropped 

 against the trunk and not inclined inversely to the direction of move- 

 ment. 



We may add, in passing, a new cause of fatigue and wear for the 

 hock and the fetlock, resulting from overburdening these agents of 

 impulsion, which must here elevate the body before projecting it hor- 

 izontally, the only propulsive line favorable to speed. 



It follows from the preceding statements that a horse under him- 

 self is hardly capable of doing good service ; but the objections vary 



