CA MKLS. liUISOCKROS 101 



lloliippiis Orohippus M(;s(>liip|)ijs 



have ontiiTly disapiH'arcd, or ixMiiaiii only as vosti^cs, the so-called "sj)lint 

 hones." The structure of the modern horse shows that it deveh)ped from 

 a fixe-toed ancestor. This ancestry has been traced hack to the four-toed 

 stage. [See Guide Lcajlcf No. 3(). The Kvolufioii of the Horse] 



In the wall case at the right of the entrance is gi\en 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 Koliippus, the four-toed stage of the horse and the earliest form that 

 has been discovered. This specimen is from the Wind Kiver 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 speci- 

 mens 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, skulls 



and bones of primitive ruminants in their natural position 



in the rock, show how these specimens are sometimes found 



Giant Pigs ^nd raise questions as to how^ they got there, more easily 



an igmy asked than answered. The giant pigs, or elotheres, and 



Hippopotamus . , . . 



the pygmy hippopotamus will repay examination. 



The primitive rhinoceros-like animals are shown near the center of 



_,^. the hall on the right. It seems hard to believe that our 



Rhinoceros ^ , , x- , 



vast western country and indeed all >sorth America, was 



