232 THE MEANING OF EVOLUTION 



The old world horse was the companion of man. 

 The skeletons of those found with early man in the 

 caves of Europe look as if the horse had been a 

 creature to draw man's burdens and to serve him for 

 food, rather than to bear him upon its back. Its 

 roasted bones are often found about the old tribal 

 fires. Upon the discovery of the new world the Span- 

 iards brought with them to Mexico and to the Mis- 

 sissippi Valley the horses which carried them in their 

 battles against the Indians. In the course of these 

 frays many riders were killed and their horses roamed 

 wild. Slowly they made their way to the western 

 plains ; gradually they became tougher and more wiry ; 

 their diminished hoofs learned to catch more carefully 

 in the rocks of their mountain home; and the mus- 

 tang and bronco of more recent years are the de- 

 scendants of the little dawn horse, whose dainty skel- 

 eton is found in the rocks over which his later 

 descendants, after a long stretch of perhaps four 

 million years, are now running. 



