THE ANCESTRY OF THE HORSE 175 



browned and withered beneath the summer's 

 sun, the complex tooth had an advantage over 

 that of simpler structure, while the cutting- 

 teeth, so completely developed in the horse 

 family, enabled their possessors to crop the 

 grass as closely as one could do it with scis- 

 sors. Likewise, up to a certain point, the 

 largest, most powerful animal will not only 

 conquer, or escape from, his enemies, but pre- 

 vail over rivals of his own kind as well, and 

 thus it came to pass that those early members 

 of the horse family who were preeminent in 

 speed and stature, and harmonized best with 

 their surroundings, outstripped their fellows 

 and transmitted these qualities to their prog- 

 eny, until, as a result of long ages of natural 

 selection, there was developed the modern 

 horse. The rest man has done : the heavy, 

 slow-paced dray horse, the fleet trotter, the 

 huge Percheron, and the diminutive pony are 

 one and all the recent products of artificial 

 selection. 



