ADAPTATION TO ENVIRONMENT 33 



Before the active onslaught of lighter, lither, more 

 intelligent foes, the clumsy, inelastic types succumbed, 

 those only surviving which, through the fortunate 

 possession of more varied reactions, were able to evolve 

 modes of defense equal to the modes of attack possessed 

 by their enemies. This was a time when the quality 

 most needed for survival was the ability to perceive 

 enemies afar and to flee from them. The majority of 

 the leaf-eating species could not stand this test and 

 perished. Those more plastic forms which survived 

 became our modern horse, deer, antelope, ox and ele- 

 phant. Many, unable to evolve the acute senses and 

 fleet limbs necessary for the combat on the ground, 

 shrank from the fray and acquired more negative and 

 passive means of defense. Some, like the bat, escaped 

 into the air. Others, such as the squirrel and the ape, 

 took refuge in the trees. 



It was in this concourse of weak creatures which fled 

 to the trees because they lacked adequate means of 

 offense, defense or escape on the ground, that the linea- 

 ments of man's ancient ancestor might have been dis- 

 cerned. One can imagine what must have been the 

 pressure from the carnivora that forced a selective 

 transformation of the feet of the progenitor of the 

 anthropoids into grasping hands. Coincidentally with 

 the tree life, man's special line of adaptation 

 versatility was undoubtedly rapidly evolved. In- 

 creased versatility and the evolution of hands enabled 

 man to come down from the trees, millions of years 

 thereafter, to conquer the world by the further evolu- 

 tion and exercise of his organ of strategy the 

 brain. Thus we may suppose have arisen the intri- 



