214 MANUAL OF MODERN FARRIERY 



would otherwise take place is avoided, by the springy 

 action this slanting pressure produces among the 

 several bones which compose the joint. This will be 

 more readily understood by a reference to the skeleton, 

 Plate ii, fig. 21. As we have already shown, this 

 joint consists of six bones, all of which are covered 

 with articular cartilage, and each admitting of a 

 certain degree of motion, which diminishes concussion 

 by the weight, pressure, and action being diffused 

 among them all, and thus the concussion is neutralised 

 and rendered harmless. Besides the cartilaginous 

 covering, each of these bones has a membranous 

 covering, which secretes the synovia or oily fluid, 

 which we have already mentioned at page 89 and 

 elsewhere. In fact these bones may be considered 

 as so many distinct joints, all separated from each 

 other and protected from injury, yet united by different 

 ligaments, binding them so firmly together as to 

 prevent the possibility of dislocation, yet permitting 

 sufficient motion for the important office they have 

 to fulfil. Beautiful and wonderfully powerful as 

 this joint is, it is sometimes injured, too frequently, 

 we lament to say, by the brutal cruelty of those to 

 whose care horses are entrusted. In ordinary action 

 this joint has heavy work to perform, but often more 

 severe exertion is exacted from it than even its ad- 

 mirable construction can possibly perform. Much of 

 the lameness of the hind-quarters will be found, upon 

 careful examination, to be seated in the hock. If 

 the exact locality of lameness cannot be detected 

 elsewhere, we may almost consider that it is some- 

 where connected with the complicated structure of 

 the hock joint, and we may particularly refer to the 

 various diseases of this joint described towards the 

 beginning of Chapter VI, page 107. 



