304 EVOLUTION OF THE HORSE. 



disturbed for ages, and under modifying conditions which 

 have nearly doubled the comparative length of the limbs. 



Like the horses of the present day, the members of the 

 Htpparion gractle tribe differed a good deal among each other 

 as regards conformation; as we may see by the fact that 

 the cannon-bones of some are very much thicker than those 

 of others. 



The Horse of the Future. — The bones of the limbs, 

 as we have seen, are gradually assuming the character of a 

 single column, and are increasing the rigidity of their con- 

 nections between the joints necessary for locomotion. We 

 may observe a tendency to bony union between the splint 

 bones and their cannon-bones, and between the lower row of 

 the small bones of the hock and knee, and their respective 

 metatarsal and metacarpal bones. Thus we find that com- 

 paratively harmless forms of "simple" splint and '*low" 

 spavin are increasingly common among young horses sub- 

 jected to civilised conditions. They will, as suggested by 

 Mr. H. G. Rogers, gradually lose their morbid character, and 

 will become normal processes of development. Agreeably 

 to this, we may note that such splints and spavins are less 

 liable to injuriously affect the usefulness of a thoroughbred 

 than of, for instance, a Mongolian pony or a South American 

 broncho. As ages roll on, the splint bones will disappear, 

 d.Vi^ pari passu, the small bones of the knee and hock which 

 rest on them. The increasing prevalence of '' side-bones " 

 among heavy cart-horses seems to justify the idea that the 

 Shires and Clydesdales of the near future will have no lateral 

 cartilages. Among other changes, the bones of the sternum 

 will in time become joined together, and anchylosis will 

 take place between the pelvis and sacrum. The racer will 

 become comparatively longer in the legs and neck, stronger 

 in the loins, rounder in the barrel and better ribbed up than 

 he now is ; and the draught animal will become shorter in the 

 limbs, and more massive in muscle. Both will increase in 

 height and docility. 



