32 HORSE AND MAN. 



Those of the lower jaw will sometimes curl over the 

 top of the head, while those of the upper jaw, on 

 account of the greater curvature of the socket, will 

 continue their growth until they form a perfect ring. 

 Examples of these overgrowths may be seen in the 

 College of Surgeons. 



Eabbit- keepers must have noticed how their pets 

 are continually moving their jaws as if masticating 

 something. This movement so closely resembles that 

 of ruminant animals when they chew the cud, that 

 the Jews of old times took for granted that the 

 hare and the cony — i.e. the hyrax — chew the cud, 

 whereas they only rub the upper and lower teeth 

 against each other for the purpose of preserving the 

 chisel-like edge. 



Another needful characteristic of the hoof now 

 comes before us. In order to avoid jarring the 

 brain and spinal cord at each step, it is necessary 

 that the hoof should be elastic. 



As I have already mentioned, the general elasti- 

 city of the whole frame is largely due to the mode 

 in which the joints of the limbs are made. The 

 peculiar angle at which the fetlock is set has also an 

 influence on the elasticity, and horsemen are well 

 aware that when the pastern is too upright they feel 

 jarred at every step. 



