1 88 Charles Darwin. 



This leads us to an examination of some of these 

 extinct species which have been brought to the 

 attention of science, and which we may consider the 

 stepping-stones from the forms of to-day to an 

 ancestor in the remote past. One of the most 

 interesting examples is that of the horse. When 

 white men first came to this country, the horse was 

 not found here ; indeed, there appeared to be no 

 tradition of such an animal, and the Spaniard relied 

 almost as much upon the terror these animals 

 created in the land of the Incas, as they did upon 

 their arms, the natives believing that horse and rider 

 were one. Some of the horses of these adventurers 

 and others escaped, and from them descended what 

 are known as the wild horses of North and South 

 America. 



That horses were not found here by the white 

 discoverers is to some extent singular, as it is now 

 well known that these animals existed here in great 

 numbers in the Quaternary and Tertiary times of 

 geology ; some climatic or other change producing 

 their complete extirpation. Some idea of the 

 extent of the distribution of horses in these early 

 days can be realised when it is known that twelve 

 species have been discovered in the Quaternary 

 deposits, and more than thirty in the Tertiary ; so 

 that scientists have a remarkably complete chain of 

 evolutionary evidence in their remains. The small- 

 est of these, the Hipparion of the Eocene, was 

 about as large as a fox. It had large canine teeth, 

 three toes upon its hind feet, and four perfect toes 

 and a splint on the forefeet. In this horse the head 



