THE PREHISTORIC HORSE 5 



thereby increasing the length of stride and securing greater 

 speed. The surfaces of the joints, at first more or less open and 

 of the ball-and-socket type, changed to a grooved or pulley-like 

 form, this limiting the direction of movement forward and back- 

 ward, — a development better fitted for locomotion over level than 

 rough ground. The horse being a grazing animal, the increase 

 in height of body and length of leg necessitated elongation of 

 neck and head. The natural habitat of the earlier horse was the 



Fig. 3. Prejvalsky ponies in New York Zoological Park. Photograph by 

 courtesy of Edwin R. Sanborn 



forest, where it undoubtedly subsisted on the more tender parts 

 of plants and branches. In the course of time, however, along 

 with the increase in size came the development of teeth with 

 cutting and grinding surfaces better suited to the product of 

 grassy plains than the forest ; hence the horse eventually found 

 its natural home on the open plain or meadow where grazing 

 was afforded. 



The color of the prehistoric horse is not known, but it is sup- 

 posed to have been more or less striped, like the zebra, though 

 not brilliant in hue. The groundwork of this color was presum- 

 ably dun, or khaki. „. ... , , ... .^ 



•' ' Digitized by Microsoft® 



