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 preéminent 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. 
