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. 
