MUSCLES AND TENDONS, 9 



find that the race-horse, Hke all quadrupeds of which speed is 

 the chief characteristic, has comparatively slender bones of 

 extremely dense texture, and that his muscles are par- 

 ticularly strong for their thickness. Owing to the law of 

 compensation, which governs the conditions of animal life, it 

 is almost impossible to obtain bone of great volume, and, at 

 the same time, of the finest quality. On this account, as size 

 is indispensable with the cart-horse, we endeavour, with him, 

 to obtain large bone of sufficient strength to meet his 

 requirements. In the intermediate classes of horses, the 

 relations between volume and quality should be judged 

 according to the nature of the work in view. 



Arrangement of bones. — The relative position which 

 bones occupy with respect to each other affect their leverage, 

 weight-carrying, and concussion-resisting powers — conditions 

 which will be treated in detail when we consider the various 

 points which they affect 



Cartilage, — Cartilage or grisde is a strong, flexible;, 

 bluish-white substance which is found in connection with 

 bone, and of which there are various kinds* Articular 

 cartilage covers the ends of bones that form movable joints. 

 Temporary cartilage is bone in a transition form. The ribs are 

 connected to the breastbone by cartilages which form elastic 

 prolongations. Cartilages also are interposed between the 

 bones of various joints in order to connect or protect them. 

 The cartilage of prolongation forms an elastic continuation 

 of the top of the shoulder-blade. 



Muscles and Tendons.— The animal's moving power 

 is derived from muscles^ which form the lean of meat, and 

 which, as a rule, are attached to bones. Muscles act by 

 virtue of the property they possess of being able to shorten 

 themselves on being stimulated by the nervous system. 

 Thus, if we wish to raise, say, our right hand to the shoulder, 

 our brain telegraphs, so to speak, the order, by means of the 



