THE FACTORS OF EVOLUTION 157 



i.e., if always those are selected which have proved most 

 successful in the fight for existence. The result of such natural 

 selection must be a constant improvement of the organic world. 

 That this survival of the fittest is actually the rule in Nature 

 Darwin endeavoured to prove by an enormous mass of evidence. 



Those who are accustomed to look around with open eyes 

 will always be surprised anew at the high degree of fitness 

 observable in every organism. Most distinctly does this far- 

 reaching adaptation and fitness of organisms appear in the 

 many cases of protective coloration and mimicry which have 

 become known during recent years. 



Formerly it was thought that such adaptation could only be 

 understood on the basis of a teleological principle. Like an 

 engineer about to construct an engine, who first calculates and 

 draws on paper the single parts and their proportions to each 

 other, and then proceeds to transform the theory into reality, 

 thus the world-creating spirit, according to teleology, first 

 designed the plan of his mighty work and then created the 

 world. But there is no doubt whatever, nor need of specific 

 proof, that the means employed by Nature in the evolu- 

 tion and, speaking figuratively, in the construction of its 

 organisms, when compared with human planning, can only be 

 described as the result of blind chance. Wherever we may 

 look, we shall find in Nature an extraordinary waste of life. 

 Thousands, even millions, of descendants are produced ; 

 thousands and millions must prematurely perish, and only a few 

 reach full maturity. Indeed, the destruction of life-germs, the 

 failure is the rule, and the attainment of the aim, the natural 

 development, the rare exception. "If," says Friedrich Albert 

 Lange, " a man standing on a large heath were to fire millions 

 of barrels in all directions in order to shoot one hare ; if in 

 order to enter a locked room he were to buy ten thousand 

 different keys and try them all one after the other ; if in order 

 to procure shelter for himself he were to build a town, choose 

 one house, and leave the rest to become the play of wind and 

 weather, no one would call his action rational ; still less must 

 we look in his procedure for hidden reasons and a superior 

 wisdom." 



There is another point : the different species of animals and 



