12 The Horse Industry in New York State 



ancestor were short-crowned and covered with low ronnded cnsps 

 of enamel somewhat similar to those of swine, and differing widely 

 from the long-crowned, rather complicated molars of the modern 

 horse. 



A nnmber of stages are recognized in the evolution of the horse 

 from this early period to the present, each stage being character- 

 istic with the horse becoming more and more developed toward 

 the present-day type as the times become more and more recent. 

 Some of these stages are especially interesting because of the 

 changes brought about by the changes in natural conditions, show- 

 ing the adaptation of the animal to his environment. 



Thus with the disappearance of the side toes there was a con- 

 siderable increase in the length of the legs, especially the lower 

 part. The increased length of the lower leg increased the length 

 of the stride without decreasing its quickness, thus giving the ani- 

 mal greater speed. The heavy muscling in the' upper' leg in con- 

 nection with the increased strength at the joints gives the animal 

 greater strength. 



The increase in the lengih of limb made necessary a similar 

 increase in the length of head and neck in order to enable the 

 animal to reach the ground when grazing. The increase in the 

 length of crown development of the teeth enabled the animal to 

 subsist on the hard grasses of the dry plains, which required much 

 more thorough mastication before they could be used as food than 

 did the softer green foods of the swamps and forests, the horse's 

 early habitat. 



Such changes in the evolution of the horse adapt him to live 

 in the regions of level, smooth, and open grassy plains. In the 

 beginning the horse was better fitted for forest life, but it has 

 become more and more completely adapted to live and compete 

 with its enemies or rivals under the conditions which prevail on 

 the high dry plains. The increase in size which has occurred 

 during this evolution has depended upon the ability of the animal 

 to secure an abundance of food. This end was provided with the 

 changes in form which enabled the horse to cover larger areas 

 in a shorter length of time. 



