EVOLUTION OF THE HORSE 109 



tains the earliest known ancestors of tlie horse, the Httle four-toed 

 Eohippus, which was no bigger than a fox and on four toes scampered 

 over Tertianj rocks. As will be seen by an examination of the skeletons 

 of the horse and man, the modern horse walks on the tip of his middle 

 finger and toe. The front hoof bone corresponds to the last joint of 

 the third finger in the human hand, and the other bones of the leg corre- 

 spontl bone for bone with the structure of the finger, wrist and arm of 

 man. The similarity in structure of the skeletons of horse and 

 man is brought out in the exhibit of a rearing horse being controlled by 

 man. A comparison of these two skeletons will show that although 

 very different in proportions the bones of the one correspond with the 

 bones of the other. In the modern horse the remaining fingers or toes 

 of the fore and hind foot have entirely disappeared, or remain only as 

 vestiges, the so-called "splint bones." The structure of the modern 

 horse shows that it developed from a five-toed ancestor. This ancestry 

 has been traced back to the four-toed stage. [See Guide Leaflet No. 36. 

 The Evolution of the Horse.] 



In the wall case at the right of the entrance is given a synopsis of the 

 evolution of the foot and skull of the horse and the geological age in which 

 each stage is found. Across the alcove the visitor will find the skeleton 

 of Eohippus, the four-toed stage of the horse and the earliest form that 

 has been discovered. This specimen is from the Wind River beds of 

 Wyoming and may have lived 3,000,000 years ago. It is interesting to 

 note that while there were no horses found in this country by the white 

 settlers, America is the original home of the horse. 



Passing from skeleton to skeleton the changes that have taken place 

 in the development of the horse are easily distinguished. The exhibit 

 is made more lifelike by plaster restorations of the animals and by water- 

 color sketches showing primitive horses in their environment. These 

 paintings and models are by Charles R. Knight. In the later types of 

 the three-toed stage the two lateral toes have lost their original function 

 of support and are gradually becoming vestiges. The three-toed horse in 

 the center of the alcove is one of the most complete and finest examples 

 that has ever been unearthed. 



Opposite the horse exhibit on the other side of the hall, are series of 

 specimens illustrating the evolution of the camel, deer and other cloven- 

 hoofed animals. These animals like the cow of to-day walked on the 

 tips of the third and fourth fingers, and the gradual disappearance or 

 reduction to useless vestiges of the other fingers and toes can be traced 

 as in the horse series. 



The large blocks showing groups of skeletons of early camels, 

 Camels skulls and bones of primitive ruminants in their natural 



