LEGS 



67 



E-- 



a long lever, such as the leg represents, would not only render the steps 

 heavy and the movements awkward, Ijut it would also lower the centre of 

 gravity and seriously interfere with progression. Moreo^•er, the grace and 

 elegance of form and action which the horse now possesses could not in 

 such circumstances exist. 



Function of the Limbs.— Although the action of the fore and 

 hind extremities have much in common, their functions are in some 

 respects widely different. This might be inferred from the manner of 

 their attachment to the trunk, the fore part of which is supported, as 

 in a sling, by muscles wliich con- 

 nect it to the fore extremities. 

 By reference to fig. 44, p. 50, it 

 will be seen that there is no joint 

 or solid union between the fore- 

 limbs and the chest such as is 

 found between the hind extre- 

 mities and the pelvis. In the 

 former case the scapula or blade- 

 bone moves freely over the sur- 

 face of the ribs with which it is in 

 loose contact, while in the latter 

 the head of the thigh-bone (fig. 50) 

 is confined by strong ligaments 

 within the cup-like cavity of the 

 pelvis, with which it forms the 



hip-joint, through which the hind-limbs transmit their propulsive efforts 

 and effect the forward movement of the body. 



It will l:)e noticed later that the weioht borne bv the front limbs 

 exceeds that sustained by the hind ones, and in addition to this they 

 have also to receive and disperse the forcible impact from behind which 

 is imposed upon them in racing and jumping, and in a less degree 

 in the slower paces. Their ability to meet these requirements is 

 explained by the peculiar manner of their attachment to the trunk. 

 This, as we have seen, is effected by muscles only, which permit the 

 weight and propulsive force to fall upon the passive organs of locomotion 

 — bones, tendons, and ligaments — without exciting that violent reaction 

 which would necessarily result had the scapula a fixed articulation with 

 the trunk, such as exists between the pelvis and the thigh-bone. 



It will be seen, therefore, that besides being organs of support, the fore- 

 limbs are specially designed to break and disperse the concussion to which 

 they are exposed in the more energetic movements of the body. 



Fig. 50. — Articulation of the Hip Joint 



A A, Capsular or enclosing- ligament. B, Round ligament, 

 c, Pu bio -femoral ligament. D, Cotyloid ligament. E, Head 

 of femur. 



