jR. S. Lull — The Evolution of the Horse Family. 163 



This collection was begun in our western country in 1868, 

 before the completion of the Union Pacific Railroad, and sub- 

 sequently for several years the explorers had an escort of IT. S. 

 cavalry for protection from the assaults of the Indians. In 

 1876, the collection was seen and studied by Professor Huxley, 

 profoundly altering his views in regard to the place of evolu- 

 tion of prehistoric horses. 



The completeness of our record of the evolution of the 

 horse tells us something of the enormous numbers of ancestral 

 forms which must have existed in the more than two million 

 years that have elapsed since the first diminutive horse 

 appeared in North America. While not strongly given to 

 migration, in the course of time these animals wandered over 

 the entire world with the exception of such inaccessible places 

 as Australia and the Oceanic islands. 



It would seem that the original stock was of Eurasian deriva- 

 tion, though the great theater of the evolutionary drama was 

 soon transferred to North America, the Eurasian, African, and 

 South American horses which appear from time to time being 

 in all probability of North American origin. As we shall see, 

 the ultimate fate of the horses in both North and South 

 America was extinction, all wild horses of our own time, 

 including the asses and zebras, being confined to Asia and 

 Africa. The apparently wild bands of our western plains and 

 those which roam over the pampas of South America are feral, 

 which means that they are the descendants of domestic horses 

 that have escaped from human bondage, largely from the early 

 Spanish explorers. 



The Origin of the Horse. 



While we do not know the ultimate ancestor of the horses, 

 we are unquestionably sure of the group of mammals from 

 which they sprang. In this group, the Condylarthra, the 

 animals are five-toed on both hand and foot, also resting a 

 great part of the sole upon the ground. The wrist and ankle 

 bones are arranged in series one above the other in such a. 

 manner as to produce a weak structure when exposed to< 

 splitting strains. 



Phenacodus primcevus, one of this group found by Pro- 

 fessor Cope, was hailed by him as the " five-toed horse," and 

 its figure has appeared in many text-books as such. It is far 

 too large and in some respects too specialized to be in the 

 equine series, but its feet give one a very good idea of the 

 character of those of the antecedent horse. 



The first undoubted horselike animal appearing in the rocks 

 of North America is a little creature not more than eleven 



