X. 



THOUGHTS UPON THE MUSICAL SENSE 

 IN ANIMALS AND MAN. 



Modern biology depends, as everyone knows, upon the 

 hypothesis of a gradual transformation of all forms of life— 

 the hypothesis of the origin of species by the slow process 

 of evolution, not by a sudden act of creation. Furthermore, 

 most people are aware that biological science holds the chief 

 agent of this transformation to be the principle of natural 

 selection, discovered by Charles Darwin and Alfred Russell 

 Wallace. Out of the vast number of offspring born into the 

 world in each generation, only a very small fraction can survive 

 long enough to become the parents of the succeeding genera- 

 tion ; the rest perish from the attacks of enemies, from the 

 inclemency of weather, from hunger or thirst,— in short, they 

 succumb in the struggle for existence. No two individuals are 

 exactly alike, but every one differs in certain respects from all 

 the others : such differences sometimes increase, sometimes 

 diminish the power to succeed in the struggle for life. Those 

 individuals which possess an increased power of resistance 

 will, as a rule, survive and produce offspring, whether their 

 advantage be due to greater muscular strength, keener senses, 

 thicker fur, greater speed or power of flight, &;c. This selective 

 process being repeated in each generation, so that only those 

 individuals which possess qualities the most helpful in the 

 struggle for Hfe, are enabled to become the parents of off- 

 spring, it follows that such qualities will gradually spread over 

 all the individuals which make up the species and will grow 

 until they have attained the highest perfection. 



VOL. II. D 



