POSTERIOR MEMBER. 307 



contractions, in order to maintain the equilibrium of the fetlock which 

 receives the weight of the body, whose lever-arm has augmented. 



Finally, the results are identical when the animal machine, moving 

 at great speed, strikes the ground at each step of the gait. 



When the levers A OB and A OD (Fig. 105) are of the second class, the 

 power is always applied at A, the fulcrum is at 0, while the resistance becomes 

 the reactions, DE, BF, of the soil against the weight of the body, which are per- 

 ceived at the points B and D. By drawing the perpendiculars Oi^and OE from 

 the fulcrum, or point of relation, upon the direction of the vertical forces BF 

 and DE, it is found, as in the preceding figure, that the greater the inclination 

 of the pastern the more the lever-arms OE and OF augment at the expense of 

 the arm, OA, of the muscles, AAI. 



This implies that the obliquity of the phalangal region renders the 

 reactions of the soil against the quantity of movement with which the 

 body is animated at great speed more laborious and fatiguing for the 

 tendons. 



It results from the preceding that the inconveniences of low-jointed- 

 ness are of the same value as those of long-jointedness, and hence it 

 follows that they will be superadded to each other in horses suffering 

 simultaneously from these two defects. The same may be said of the 

 straight and the short-jointed pastern. 



These conformations, nevertheless, do not offer the same gravity in 

 all services. The long and oblique pastern renders the horse more 

 supple and more pleasant to ride ; it enables him to disperse more 

 easily the violent reaction of locomotion at great speed, and it would 

 be very desirable in the saddle-horse, the driving-horse, and the race- 

 horse, were it not a source of danger to the integrity of the tendons. 

 The short and straight pastern is strong ; it has no very prejudicial 

 influences against heavy-draught services, but it renders the reactions 

 hard and jeopardizes thereby the integrity of the osseous apparatus ; 

 hence it unfits a horse for the ridino;-school or for fast ridinar. 



To recapitulate, numerous disadvantages and sometimes advantages 

 may accrue from a pastern erring in its length and in its direction. 

 If both sides be compared, it will be seen that it is injudicious to extol 

 too much any one of these conformations in preference to that which 

 we have indicated as the beautiful : the long, low, straight, and short 

 joints will always constitute defects. 



Neatness of Outline and Freedom from Blemish. — The 

 pastern is called neat when its skin is thin, the subcutaneous connec- 

 tive tissue rather scarce, the hairs delicate and short ; the bones and 

 the tendons are then apparent in their special form and direction. 



