94 



CHAPTERS ON EVOLUTION. 



of the " splint-bones " (Fig. 34, c, c 1 , d, //,), which, according to 

 Owen, must have " dangled by the side of the large and functional 

 hoof (or third toe) like the pair of spurious hoofs behind those 

 forming the cloven foot in the ox." This conformation, continues 

 Owen, " would cause the foot of the Hipparion to sink less deep into 

 swampy soil, and be more easily withdrawn than the more simplified 

 horse's foot." Furthermore, the ulna or bone of the fore-arm, deficient 

 in the horse of to-day, is tolerably well developed in Hipparion. 



Backwards in time, and in the older Miocene formations of Europe, 

 another fossil horse was disentombed, and was duly described under 

 the name of Anchitherium. This latter horse possesses a completely 

 developed ulna (Fig. 32, u) in the fore-arm, and fibula (Fig. 33, fi) in 

 the leg ; but its chief point of interest lies in the fact that each foot 



FORE-FEET. 



PROTOHIPPUS AND MIOHIPPUS AND 

 HORSE. PLIOHIPPUS. HIPPARION. ANCHITHERIUM. MESOHIPPUS. OROHIPPUS. 



FIG. 34. 



possessed three fully developed toes (Fig. 34, D, D 1 , d, d,} which ap- 

 parently must have touched the ground in walking. Already our splint- 

 bones are seen to better their condition as we pass backwards through 

 the ages, and to appear as the natural supports of well-developed second 

 and fourth toes. Here the geological history of the horse in the 

 Old World may be said practically to end. Modern history assures 

 us that the first horses which peopled the New World, and whose 

 descendants roam over American prairies as the famed mustangs, 

 were imported by the Spaniards at the period of the Mexican 

 conquest Geology has a more curious tale to relate of the New 



