AND PERSONALITY 



cold, wet Shetland Islands, is used as a circus horse. The 

 zebra, a fast and furious runner, mingling with the antelopes, 

 exists in great numbers among lions and other Carnivora 

 that always seek its flesh. 



Because the horse family presents a fair test of the 

 validity of the energy conception in our thesis, we turned 

 at long last to a study of the pattern of the energy-con- 

 trolling organs of these various types of horses. To that end 

 we studied 23 1 horses. Among these were burros, mules, 

 work horses, western horses, hunters, saddle horses, polo 

 ponies, Shetland ponies, zebras, Arabian stallions, Ken- 

 tucky thoroughbreds, newborn foals, and fetuses. 



For our purpose, we tested these data to see whether there 

 was an energy formula for horses bred for carrying a pack; 

 another for horses bred for slow power, such as the work 

 horse; another for horses with more mobile energy, such 

 as the saddle horse and hunter; another for horses with 

 great endurance and gentle disposition, such as the Arabian; 

 and another for horses with great speed or explosive energy, 

 such as the thoroughbred. 



We also contrasted these various types of horses with the 

 wild zebra of the hot tropics and the Shetland pony of the 

 cold north to see what might be the influence of climate 

 upon their energy mechanisms. 



For thousands of years the horse has been developed 

 by man through breeding selection. Breeding selection by 

 man partly suspends the law of natural selection in the wild, 

 such as is effected in the lion, the tiger, the leopard in 

 fact, in all the carnivores, the rodents, and the hoofed 

 animals. 



In the natural selection imposed by the carnivores upon 

 the herbivores, there has always been involved the extermi- 

 nation of those that are weakest in muscle and the least fit 

 in the special senses; therefore, natural selection leaves 

 those with the keenest senses, the fleetest feet, the most 

 intelligent minds to reproduce their kind. In this selection 



127 



