48 EVOLUTION, SOCIAL AND ORGANIC 



be able to obtain almost any kind of a bird by 

 selecting as parents those pigeons which had 

 the desired characteristics developed to the 

 most pronounced degree, and then again se- 

 lecting in the same way from their progeny. 

 In this way were produced birds so different 

 from each other and their ancestors as the 

 tumbler, the fantail, the pouter, and about a 

 hundred and fifty other varieties. The same 

 with horses. If the breeder desired draught 

 horses, he selected for parents those 

 animals with massive shoulders and sturdy 

 limbs. When a racer wins a "classic" race, it 

 is at once sent to the stud-farm. Although in 

 the zenith of its powers it races no more; ,i,t* 

 is "selected" for another and more important 

 role — the reproduction and, it is hoped, the 

 accentuation of the characteristics which 

 enabled it to outrun its competitors. 



All this impressed on Darwin's mind the 

 importance of the word "selection," which 

 appears in the title of his theory and the sub- 

 title of his epoch-making book. Could it be 

 possible that nature contained some principle 

 or combination of principles, which performed 

 among wild animals a part analogous to that 

 of the breeder, among domestic animals? 

 Darwin discovered that this is precisely what 

 takes place. 



