Chap. 38 



ORGANIC EVOLUTION CONSERVATION 



785 



Fig. 38.6. Evolution of the horse. Within each section from left to right the 

 drawings show: a reconstruction of an ancestor of the horse in the surroundings 

 in which it is believed to have lived; fossil remains of the animal's fore and hind 

 feet displaying the progressive reduction in the lateral digits; one of the molar 

 teeth and the skull. Only the teeth are drawn to scale. The oldest horse (eohippus) 

 in the bottom section, was about the size of a fox terrier (12 inches tall). (Cour- 

 tesy, Rogers, Hubbell, and Byers: Man and the Biological World, ed. 2. New York, 

 McGraw-Hill Book Co., 1952.) 



